endothelin-1 and Diabetes-Mellitus--Type-2

The heavy impact of obesity on the development and progression of cardiovascular disease has sparked sustained efforts to uncover the mechanisms linking excess adiposity to vascular dysfunction. Impaired vasodilator reactivity has been recognized as an early hemodynamic abnormality in obese patients, but also increased vasoconstrictor tone importantly contributes to their vascular damage. In particular, upregulation of the endothelin (ET)-1 system, consistently reported in these patients, might accelerate atherosclerosis and its complication, given the pro-inflammatory and mitogenic properties of ET-1. In recent years, a number of gut hormones, in addition to their role as modulators of food intake, energy balance, glucose and lipid metabolism, and insulin secretion and action, have demonstrated favorable vascular actions. They increase the bioavailability of vasodilator mediators like nitric oxide, but they have also been shown to inhibit the ET-1 system. These features make gut hormones promising tools for targeting both the metabolic and cardiovascular complications of obesity, a view supported by recent large-scale clinical trials indicating that novel drugs for type 2 diabetes with cardiovascular potential may translate into clinically significant advantages. Therefore, there is real hope that better understanding of the properties of gut-derived substances might provide more effective therapies for the obesity-related cardiometabolic syndrome.

Topics: Anti-Obesity Agents; Diabetes Mellitus, Type 2; Endothelin-1; Gastrointestinal Hormones; Humans; Insulin Resistance; Obesity; Peptide Hormones; Vasoconstriction; Vasoconstrictor Agents

Type 2 diabetes (T2D) accounts for about 90% of all diabetes patients and incurs a heavy global public health burden. Up to 50% of T2D patients will eventually develop neuropathy as T2D progresses. Diabetic peripheral neuropathy (DPN) is a common diabetic complication and one of the main causes of increased morbidity and mortality of T2D patients. Obstructive sleep apnea (OSA) affects over 15% of the general population and is associated with a higher prevalence of T2D. Growing evidence also indicates that OSA is highly prevalent in T2D patients probably due to diabetic peripheral neuropathy. However, the interrelations among diabetic peripheral neuropathy, OSA, and T2D hitherto have not been clearly elucidated. Numerous molecular mechanisms have been documented that underlie diabetic peripheral neuropathy and OSA, including oxidative stress, inflammation, endothelin-1, vascular endothelial growth factor (VEGF), accumulation of advanced glycation end products, protein kinase C (PKC) signaling, poly ADP ribose polymerase (PARP), nitrosative stress, plasminogen activator inhibitor-1, and vitamin D deficiency. In this review, we seek to illuminate the relationships among T2D, diabetic peripheral neuropathy, and OSA and how they interact with one another. In addition, we summarize and explain the shared molecular mechanisms involved in diabetic peripheral neuropathy and OSA for further mechanistic investigations and novel therapeutic strategies for attenuating and preventing the development and progression of diabetic peripheral neuropathy and OSA in T2D.

Topics: Animals; Diabetes Complications; Diabetes Mellitus, Type 2; Diabetic Neuropathies; Disease Progression; Endothelin-1; Glycation End Products, Advanced; Humans; Mice; Neurotransmitter Agents; Oxidative Stress; Plasminogen Activator Inhibitor 1; Poly(ADP-ribose) Polymerases; Prevalence; Protein Kinase C; Rats; Sleep Apnea, Obstructive; Vascular Endothelial Growth Factor A

Obesity is a metabolic disorder of increasing prevalence worldwide and a risk factor for the development of insulin resistance (IR), metabolic syndrome and type 2 diabetes. Obesity is related to endothelial dysfunction through indirect mechanisms such as IR and the associated risk factors, and through direct mechanisms including the production of proinflammatory adipokines and elevated levels of free fatty acids (FFAs) by adipose tissue. Both clinical and experimental studies using genetic and diet-induced animal models of obesity have consistently shown impaired metabolic, agonistor flow-induced vasodilatations correlated with the amount of visceral adipose tissue and improved by dietary interventions and exercise. Compromised bioavailability of NO due to oxidative stress emerges as a main cause of endothelial dysfunction in obesity. Inflamed adipose tissue due to hypoxia, and in particular perivascular adipose tissue (PVAT), secrete larger amounts of reactive oxygen species (ROS) and adipokines that deteriorate NO signaling pathways. Abnormal production and activity of the vasoconstrictor/proatherogenic peptide endothelin-1 (ET-1) is also a hallmark of the obesity- associated endothelial dysfunction. Obesity, and in particular visceral obesity, is one of the main causes of IR, and the pathogenic factors that induce endothelial dysfunction in the earlier stages of obesity will further deteriorate the insulin signaling pathways in endothelial cells thus leading to blunted vasodilatation and abnormal capillary recruitment and substrate delivery by insulin to the target tissues. The present review is an attempt to summarize the current knowledge and the latest novel findings on the pathogenic mechanisms underlying endothelial dysfunction in obesity, in particular the local contribution of oxidative stress and inflammatory response from PVAT, and its role in the obesity-associated cardiovascular and metabolic complications.

Topics: Adipokines; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Humans; Insulin Resistance; Nitric Oxide; Obesity; Oxidative Stress; Reactive Oxygen Species; Risk Factors; Vasoconstriction; Vasodilation

Treatment of chronic kidney disease (CKD) can slow its progression to end-stage renal disease (ESRD). However, the therapies remain limited. Blood pressure control using angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) has the greatest weight of evidence. Glycemic control in diabetes seems likely to retard progression. Several metabolic disturbances of CKD may prove to be useful therapeutic targets but have been insufficiently tested. These include acidosis, hyperphosphatemia, and vitamin D deficiency. Drugs aimed at other potentially damaging systems and processes, including endothelin, fibrosis, oxidation, and advanced glycation end products, are at various stages of development. In addition to the paucity of proven effective therapies, the incomplete application of existing treatments, the education of patients about their disease, and the transition to ESRD care remain major practical barriers to better outcomes.

Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Anti-Inflammatory Agents, Non-Steroidal; Antihypertensive Agents; Diabetes Mellitus, Type 2; Disease Progression; Endothelin-1; Humans; Hypertension; Kidney Failure, Chronic; Oleanolic Acid; Pyridones; Renal Insufficiency, Chronic; Renin-Angiotensin System

Endothelin-1 (ET-1) is a vasoconstrictor, proinflammatory and proliferative endothelial cell-derived peptide that is of significant importance in the regulation of vascular function. It is involved in the development of endothelial dysfunction including important interactions with nitric oxide. The expression and functional effects of ET-1 and its receptors are markedly altered during development of cardiovascular disease. Increased production of ET-1 and its receptors mediate many pathophysiological events contributing to the development of atherosclerosis and vascular complications in diabetes mellitus. The present review focuses on the pathophysiological role of ET-1 and the potential importance of ET receptors as a therapeutic target for treatment of these conditions.

Topics: Animals; Arteriosclerosis; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Humans; Nitric Oxide; Receptors, Endothelin; Vasoconstriction

It is well known that adverse conditions during intrauterine life, such as intrauterine growth restriction (IUGR), can result in permanent changes in the physiology and metabolism of the newborn, which in turn leads to an increased risk of disease in adulthood (fetal origin of adult disease hypothesis). In the first part of this review the epidemiological studies in which a correlation between low birth weight and chronic pathologies in adulthood was observed are reported. The second part of the review is focused on metabolomics studies that have revealed an altered metabolism in IUGR patients compared to controls. Together with more classic biomarkers of IUGR, such as endothelin-1, leptin, protein S100B and visfatin, the new holistic metabolomics approach has assumed a crescent role in the identification of disorders in the neonatal metabolic profile, determined by the interconnection of the different processes.

Topics: Biomarkers; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Endothelin-1; Epigenomics; Female; Fetal Growth Retardation; Fetal Nutrition Disorders; Genotype; Humans; Infant, Low Birth Weight; Infant, Newborn; Leptin; Metabolomics; Phenotype; Pregnancy; Prenatal Exposure Delayed Effects; Risk Factors

Diabetic nephropathy is a microvascular complication of diabetes. Specifically, it represents a major cause of morbidity and mortality in type 1 and type 2 diabetic subjects and has become the leading cause of end-stage renal disease in the Western world. Diabetic nephropathy appears to develop as a result of interactions between environmental insults and genetic susceptibility. Indeed, hyperglycemia is a clinical prerequisite for this complication, but it should be noted that only a subset of diabetic subjects will ultimately develop nephropathy. Over recent decades, cellular and molecular mechanisms underlying diabetic nephropathy have been increasingly delineated. In particular, diabetic kidney disease appears to occur as a result of the deleterious effects of both metabolic and hemodynamic insults, which at the cellular level lead to the activation of intracellular signaling pathways and transcription factors, thus triggering the production/release of cytokines, chemokines and growth factors, which mediate and/or amplify the renal damage. This ultimately leads to the structural and functional features characteristic of diabetic kidney disease. In the present review we summarize the evidence for key mediators of injury, which appear to be excellent treatment targets in diabetic nephropathy. The targets include various vasoactive hormones, the biochemical processes of the advanced glycation and protein kinase C. Furthermore, we review current and potentially new renoprotective therapies in the setting of diabetes.

Topics: Angiotensin II; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelin-1; Glycation End Products, Advanced; Humans; Hypertension; Protein Kinase C; Urotensins

The global epidemic of diabetes mellitus has led to a continuous increase in the prevalence of diabetic nephropathy over the past years. Thus, diabetic nephropathy is currently the number one cause of end-stage renal disease in the Western world. It represents a major public health problem for which more effective prevention and treatment strategies are needed. Thiazolidinediones (TZDs) are a class of agents that lower blood glucose through reduction of insulin resistance in patients with type 2 diabetes. Growing evidence support the concept that TZDs have several beneficial effects on the cardiovascular system beyond their effects on glycemic control. These benefits include: blood pressure lowering, triglyceride reduction, high-density lipoprotein-cholesterol elevation, and reduction in subclinical vascular inflammation. Moreover, data from several animal and human studies support the notion that TZDs reduce urine albumin excretion and may prevent development of renal injury. The relative lack of evidence, however, demonstrating the effects of TZDs on hard renal outcomes mandates the need for well-designed trials with this particular objective. This paper summarizes all the data from clinical and experimental studies relevant to a possible renoprotective effect of TZDs and discusses actions of these compounds that may contribute toward this effect.

Topics: Albuminuria; Animals; Blood Pressure; Chromans; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelin-1; Humans; Hypoglycemic Agents; Kidney; Kidney Failure, Chronic; Pioglitazone; PPAR gamma; Randomized Controlled Trials as Topic; Renin-Angiotensin System; Risk Factors; Rosiglitazone; Thiazolidinediones; Time Factors; Troglitazone

The prevalence of type 2 diabetes globally is reaching epidemic proportions. Type 2 diabetes is strongly associated with increased risk of cardiovascular disease. Atherosclerosis is thought to arise as a result of a chronic inflammatory process within the arterial wall. Insulin resistance is central to the pathogenesis of type 2 diabetes and may contribute to atherogenesis, either directly or through associated risk factors. The peroxisome proliferator-activated receptor-gamma agonists, the thiazolidinediones, pioglitazone and rosiglitazone, are insulin sensitizing agents, that are licensed for the management of hyperglycaemia. Growing evidence supports an array of additional effects of thiazolidinedione therapy, both immunomodulatory and antiinflammatory, which may attenuate atherogenesis in type 2 diabetes.. Studies have shown that thiazolidinedione therapy may lead to risk factor modulation in type 2 diabetes. Thiazolidinediones treatment has been shown to reduce blood pressure, modify the atherogenic lipid profile associated with type 2 diabetes, reduce microalbuminuria and ameliorate the prothrombotic diathesis. Further evidence suggests that thiazolidinediones therapy inhibits the inflammatory processes which may be involved in atherosclerotic plaque initiation, propagation and destabilization.. Modification of insulin resistance by thiazolidinedione therapy in type 2 diabetes and the range of pleiotropic effects may not only impact on incident type 2 diabetes, but also on associated cardiovascular disease. Numerous large clinical endpoint studies are under way to investigate these issues.

Topics: Albuminuria; Arteriosclerosis; Blood Pressure; C-Reactive Protein; Carotid Arteries; Coronary Restenosis; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Humans; Hyperglycemia; Insulin Resistance; Lipoproteins; Matrix Metalloproteinases; Metformin; Muscle, Smooth, Vascular; Pioglitazone; Plasminogen Activator Inhibitor 1; PPAR gamma; Rosiglitazone; Thiazolidinediones

Endothelin-1 is mainly synthesized by the vascular endothelial cells and acts on the vascular smooth muscle. Because of its vasoconstrictor and mitogenic effects it plays a role in the development of vascular diseases. In diabetes mellitus atherosclerosis is accelerated. The authors summarize the available data of the role of endothelin-1 in Type 1 and Type 2 diabetes mellitus and the development of diabetic complication.

Topics: Animals; Diabetes Complications; Diabetes Mellitus; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Endothelin-1; Humans; Rats

Social anxiety (SA) and depression are prevalent, often comorbid disorders, associated with poor psychosocial functioning. Experimental psychopathology approaches can clarify the transdiagnostic mechanisms underlying these disorders, but most laboratory tasks are limited. We developed and validated the Audio-Dialogue Inductions of Social Stress (A-DISS) experimental task to model real-time rejection sensitivity in a realistic and developmentally relevant context. Participants are asked to imagine overhearing peers at a party talking badly about them (Rejection) or a teacher at their school (Neutral).. The Rejection condition elicited higher negative affect/lower positive affect while the Neutral condition sustained stable affect. Findings were consistent across gender and race/ethnicity. Moderation analyses were statistically significant; participants with elevated SA or depression reported feeling more rejected, insecure, and anxious after Rejection than those with below average symptoms.. Findings provide preliminary validation of a novel peer rejection task for research on understanding the affective experience of real-time rejection overall, especially for those with elevated SA and depression. SA and depression symptoms each uniquely moderating the effects of Rejection exposure on similar affective states, suggests individuals with SA or depression may benefit from interventions targeting specific reactions to rejection/stress and transdiagnostic risk factors.. Our results suggest that T lymphocyte immune dysfunction does exist in adult ITP patients and plays an important role in the pathogenesis of ITP.. ClinicalTrials.gov, identifier NCT03575988.. Brown/beige adipocyte-specific h

Topics: A549 Cells; Acute Lung Injury; Adipose Tissue, Brown; Adipose Tissue, White; Adolescent; Adult; Aged; Animals; Anthropometry; Anti-Inflammatory Agents; Antiviral Agents; Arachidonic Acid; Archaeoglobus fulgidus; Australia; Blood Glucose; Blotting, Western; Carcinoma, Hepatocellular; Cathartics; Cell Differentiation; Chemokine CCL2; Child; China; Colonoscopy; Crosses, Genetic; Cyclin B1; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Drugs, Chinese Herbal; Endothelin-1; Endothelium, Vascular; Enzyme-Linked Immunosorbent Assay; Female; Finland; Follow-Up Studies; Genes, Dominant; Glycated Hemoglobin; Hepatitis B e Antigens; Hepatitis B virus; Hepatitis B, Chronic; Homeodomain Proteins; Humans; Hypothalamus; Incidence; Inflammatory Bowel Diseases; Interleukin-1beta; Interleukin-6; Italy; Lipopolysaccharides; Liver Cirrhosis; Liver Neoplasms; Lung; Male; Mice; MicroRNAs; Middle Aged; Motivational Interviewing; NAD; Neuroendocrine Tumors; NF-kappa B; Nitric Oxide; Nitriles; Outpatients; Oxidoreductases; Phenotype; Pilot Projects; Polyethylene Glycols; Polymorphism, Genetic; Prospective Studies; Protein Interaction Maps; Quality of Life; Reproducibility of Results; Shewanella; Signal Transduction; Spain; Sulfides; Sulfones; Thermogenesis; Transcription Factors; Treatment Outcome; Tumor Necrosis Factor-alpha; Uncoupling Protein 1; United Kingdom

The aim of study was the optimization of treatment in patients with arterial hypertension and coexistent type 2 diabetes mellitus. The study involved 96 persons with arterial hypertension and type 2 diabetes mellitus (2 of them were excluded). Patients with arterial hypertension and type 2 diabetes mellitus (n=94) were divided in two subgroups: persons from the first (n=54) were treated by telmisartan 40-80 mg/day; second (n=40) - by lisinopril 10-20 mg/day. People from the first subgroup (n=54) were divided in Іa (n=25) and Іb (n=29) according to the level of endothelin-1. Persons from the Іa subgroup with less than 10 pg/ml levels of endothelin were treated by telmisartan 40 mg/day. People from the Іb subgroup with more than 10 pg/ml levels of endothelin were treated by telmisartan 80 mg/day. Patients were observed by echocardiography, albumin excretion rate in six months and by glycated hemoglobin in 3 months. Telmisartan is not worse than lisinopril according to protection of heart and kidney. Under the influence of treatment with telmisartan at a dose of 40 mg/day in subjects with arterial hypertension and type 2 diabetes mellitus and less than 10 pg/ml level of endothelin-1, the values of albumin excretion rate decreased by 9,7% (p=0,0328), and left ventricular mass index - by 6,7% (p=0,0007). In coexistent patients with greater than 10 pg/ml level of endothelin-1 and 80 mg/day dose of telmisartan, the level of albumin excretion rate was reduced by 4,9% (p=0,0435), and left ventricular mass index - by 3,1% (p<0,0001). If the level of this indicator is less than 10 pg/ml, the dose of telmisartan is 40 mg/day, if the level of endothelin-1 is more than 10 pg/ml, the dose of telmisartan is 80 mg/day.

Topics: Albuminuria; Antihypertensive Agents; Blood Pressure; Comorbidity; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelin-1; Glycated Hemoglobin; Humans; Hypertension; Lisinopril; Middle Aged; Renin-Angiotensin System; Telmisartan; Treatment Outcome

To observe the effect of Sancaijiangtang powders on plasma nitric oxide and endothelin-1 levels. We sought to identify the common pathological link and mechanism of action for Traditional Chinese medicine in type 2 diabetes mellitus and vascular dementia, and to explicate the material basis for treating the different diseases with the same method in Traditional Chinese Medicine.. In total, 168 patients with type 2 diabetes mellitus and vascular dementia were enrolled in the study, and randomly divided into two groups by simple randomization. Patients in the treatment group received oral Sancaijiangtang powders with pioglitazone hydrochloride three times daily, while patients in the control group received pioglitazone hydrochloride alone. The treatment course was for 12 weeks. Mini-mental state examinations (Chinese version) and Montreal Cognitive Assessments (Beijing version) were performed, and fasting plasma glucose, fasting insulin, hemoglobin A1c, homeostasis model assessment of insulin resistance, plasma nitric oxide and endothelin-1 levels were measured before and after the treatment.. The post-treatment levels for all measurements in both groups were better than pre-treat- ment levels (P < 0.05). The post-treatment levels for all measurements in the treatment group were better than the levels measured in the control group (P < 0.05).. Type 2 diabetes mellitus and vascular dementia have common pathological mechanisms for insulin resistance and endothelium dysfunction. Sancaijiangtang powders could improve the release of nitric oxide and inhibit the secretion of endothelin-1. Therefore, the material basis exists for treating the different diseases with the same method in Traditional Chinese Medicine.

Topics: Aged; Dementia, Vascular; Diabetes Mellitus, Type 2; Drugs, Chinese Herbal; Endothelin-1; Female; Glycated Hemoglobin; Humans; Male; Middle Aged; Nitric Oxide; Single-Blind Method

Despite optimal treatment, including renin-angiotensin system (RAS) inhibitors, patients with type 2 diabetic nephropathy have high cardiorenal morbidity and mortality related to residual albuminuria. We evaluated whether or not atrasentan, a selective endothelin A receptor antagonist, further reduces albuminuria when administered concomitantly with maximum tolerated labeled doses of RAS inhibitors. We enrolled 211 patients with type 2 diabetes, urine albumin/creatinine ratios of 300-3500 mg/g, and eGFRs of 30-75 ml/min per 1.73 m(2) in two identically designed, parallel, multinational, double-blind studies. Participants were randomized to placebo (n=50) or to 0.75 mg/d (n=78) or 1.25 mg/d (n=83) atrasentan for 12 weeks. Compared with placebo, 0.75 mg and 1.25 mg atrasentan reduced urine albumin/creatinine ratios by an average of 35% and 38% (95% confidence intervals of 24 to 45 and 28 to 47, respectively) and reduced albuminuria≥30% in 51% and 55% of participants, respectively. eGFR and office BP measurements did not change, whereas 24-hour systolic and diastolic BP, LDL cholesterol, and triglyceride levels decreased significantly in both treatment groups. Use of atrasentan was associated with a significant increase in weight and a reduction in hemoglobin, but rates of peripheral edema, heart failure, or other side effects did not differ between groups. However, more patients treated with 1.25 mg/d atrasentan discontinued due to adverse events. After stopping atrasentan for 30 days, measured parameters returned to pretreatment levels. In conclusion, atrasentan reduced albuminuria and improved BP and lipid spectrum with manageable fluid overload-related adverse events in patients with type 2 diabetic nephropathy receiving RAS inhibitors.

Topics: Aged; Albuminuria; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Atrasentan; Blood Pressure; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Double-Blind Method; Drug Therapy, Combination; Endothelin-1; Female; Humans; Kidney Function Tests; Lipids; Male; Middle Aged; Pyrrolidines

In type 2 diabetes patients, endothelin (ET) receptor blockade may enhance blood flow responses to exercise training. The combination of exercise training and ET receptor blockade may represent a more potent stimulus than training alone to improve vascular function, physical fitness and glucose homeostasis. We assessed the effect of an 8 week exercise training programme combined with either ET blockade or placebo on vasculature, fitness and glucose homeostasis in people with type 2 diabetes. In a double-blind randomized controlled trial, brachial endothelium-dependent and ‑independent dilatation (using flow-mediated dilatation and glyceryl trinitrate, respectively), glucose homeostasis (using Homeostasis Model Assessment for Insulin Resistance (HOMA-IR)) and physical fitness (maximal cycling test) were assessed in 18 men with type 2 diabetes (60 ± 6 years old). Subjects underwent an 8 week exercise training programme, with half of the subjects receiving ET receptor blockade (bosentan) and the other half a placebo, followed by reassessment of the tests above. Exercise training improved physical fitness to a similar extent in both groups, but we did not detect changes in vascular function in either group. This study suggests that there is no adaptation in brachial and femoral artery endothelial function after 8 weeks of training in type 2 diabetes patients. Endothelin receptor blockade combined with exercise training does not additionally alter conduit artery endothelial function or physical fitness in type 2 diabetes.

Topics: Aged; Blood Glucose; Bosentan; Brachial Artery; Diabetes Mellitus, Type 2; Double-Blind Method; Endothelin Receptor Antagonists; Endothelin-1; Endothelium, Vascular; Homeostasis; Humans; Male; Middle Aged; Physical Conditioning, Human; Physical Fitness; Sulfonamides; Vasodilation

To demonstrate the efficacy of exenatide versus insulin glargine on endothelial functions and cardiovascular risk markers.. Thirty-four insulin and incretin-naive patients with type 2 diabetes mellitus (body mass index 25-45 kg/m(2)) who received metformin for at least two months were randomized to exenatide or insulin glargine treatment arms and followed-up for 26 weeks. Measurements of endothelial functions were done by ultrasonography, cardiovascular risk markers by serum enzyme-linked immunosorbent assay, and total body fat mass by bioimpedance.. Levels of high sensitivity-C-reactive protein and endothelin-1 decreased (27.5% and 18.75%, respectively) in the exenatide arm. However, in the insulin glargine arm, fibrinogen, monocyte chemoattractant protein-1, leptin and endothelin-1 levels (13.4, 30.2, 47.5, and 80%, respectively) increased. Post-treatment flow mediated dilatation and endothelium independent vascular responses were significantly higher in both arms (p=0.0001, p=0.0001). Positive correlation was observed between the changes in body weight and endothelium-independent vasodilatation, leptin, plasminogen activator inhibitor type 1 and endothelin-1 in both arms (r=0.376, r=0.507, r=0.490, r=0.362, respectively).. Insulin glargine improved endothelial functions, without leading to positive changes in cardiovascular risk markers. Exenatide treatment of 26 weeks resulted in reduced body weight and improvement in certain cardiovascular risk markers and endothelial functions.

Topics: Biomarkers; Blood Glucose; Brachial Artery; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Enzyme-Linked Immunosorbent Assay; Exenatide; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; Male; Middle Aged; Peptides; Prognosis; Risk Factors; Ultrasonography; Vasodilation; Venoms

Endothelial progenitor cells (EPC) represent an endogenous repair mechanism involving rendothelialization and neoangiogenesis. Patients with both diabetes and vascular disease have low numbers of circulating EPC. The endothelium-derived peptide, endothelin-1 (ET-1), is increased in patients with type 2 diabetes and vascular complications and has been suggested to contribute to endothelial dysfunction. Therefore, we investigated the relation between EPC and plasma ET-1 and the effect of dual ET-1 receptor antagonist treatment.. In this double blind study patients with type 2 diabetes mellitus and microalbuminuria were randomized to treatment with the dual ETA/ETB receptor antagonist bosentan treatment (125mg bid; n=17) or placebo (n=19) for four weeks. Different EPC subpopulations were enumerated by flow cytometry using triple staining (CD34, CD133, KDR) at baseline at the end of treatment. Viability was assessed by 7AAD and Annexin-V-staining.. Baseline ET-1 levels correlated significantly with C-reactive protein levels. Patients with ET-1 levels above the median value had higher levels of CD34(+)CD133(+) and CD34(+)KDR(+) EPC. There was no difference in CD34(+) and CD34(+)CD133(+)KDR(+) cells, markers of EPC apoptosis or circulating markers of endothelial damage between patients with ET-1 levels below or above the median. Four week treatment with bosentan did not change EPC levels.. Among patients with type 2 diabetes and vascular disease, high plasma levels of ET-1 are associated with higher number of EPC. The recruitment of EPC does not seem to be regulated via ET-1 receptor activation since treatment with a dual ET-1 receptor blocker did not affect circulating EPC numbers.

Topics: Aged; Albuminuria; Biomarkers; Bosentan; Diabetes Mellitus, Type 2; Double-Blind Method; Endothelial Cells; Endothelin A Receptor Antagonists; Endothelin-1; Endothelium, Vascular; Female; Humans; Male; Middle Aged; Receptor, Endothelin A; Stem Cells; Sulfonamides

Dyslipidemia contributes to endothelial dysfunction in type 2 diabetes mellitus. Fenofibrate (FF), a ligand of the peroxisome proliferator-activated receptor-α (PPARα), has beneficial effects on microvascular complications. FF may act on the endothelium by regulating vasoactive factors, including endothelin-1 (ET-1). In vitro, FF decreases ET-1 expression in human microvascular endothelial cells. We investigated the molecular mechanisms involved in the effect of FF treatment on plasma levels of ET-1 in type 2 diabetes mellitus patients.. FF impaired the capacity of transforming growth factor-β to induce ET-1 gene expression. PPARα activation by FF increased expression of the transcriptional repressor Krüppel-like factor 11 and its binding to the ET-1 gene promoter. Knockdown of Krüppel-like factor 11 expression potentiated basal and transforming growth factor-β-stimulated ET-1 expression, suggesting that Krüppel-like factor 11 downregulates ET-1 expression. FF, in a PPARα-independent manner, and insulin enhanced glycogen synthase kinase-3β phosphorylation thus reducing glycogen synthase kinase-3 activity that contributes to the FF-mediated reduction of ET-1 gene expression. In type 2 diabetes mellitus, improvement of flow-mediated dilatation of the brachial artery by FF was associated with a decrease in plasma ET-1.. FF decreases ET-1 expression by a PPARα-dependent mechanism, via transcriptional induction of the Krüppel-like factor 11 repressor and by PPARα-independent actions via inhibition of glycogen synthase kinase-3 activity.

Topics: Apoptosis Regulatory Proteins; Binding Sites; Brachial Artery; Cell Cycle Proteins; Cell Line; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Down-Regulation; Dyslipidemias; Endothelial Cells; Endothelin-1; Fenofibrate; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Hypolipidemic Agents; Phosphorylation; PPAR alpha; Promoter Regions, Genetic; Repressor Proteins; Signal Transduction; Time Factors; Transcription, Genetic; Transfection; Transforming Growth Factor beta; Vasodilation

Endothelial dysfunction has been proposed as the underlying cause of diabetic angiopathy that eventually leads to cardiovascular disease, the major cause of death in diabetes. We recently demonstrated the ameliorating effect of regular vitamin D intake on the glycemic status of patients with type 2 diabetes (T2D). In this study, the effects of improvement of vitamin D status on glycemic status, lipid profile and endothelial biomarkers in T2D subjects were investigated.. Subjects with T2D were randomly allocated to one of the two groups to receive either plain yogurt drink (PYD; containing 170 mg calcium and no vitamin D/250 mL, n1 = 50) or vitamin D3-fortified yogurt drink (FYD; containing 170 mg calcium and 500 IU/250 mL, n2 = 50) twice a day for 12 weeks. Anthropometric measures, glycemic status, lipid profile, body fat mass (FM) and endothelial biomarkers including serum endothelin-1, E-selectin and matrix metalloproteinase (MMP)-9 were evaluated at the beginning and after the 12-week intervention period.. The intervention resulted in a significant improvement in fasting glucose, the Quantitative Insulin Check Index (QUICKI), glycated hemoglobin (HbA1c), triacylglycerols, high-density lipoprotein cholesterol (HDL-C), endothelin-1, E-selectin and MMP-9 in FYD compared to PYD (P < 0.05, for all). Interestingly, difference in changes of endothelin-1, E-selectin and MMP-9 concentrations in FYD compared to PYD (-0.35 ± 0.63 versus -0.03 ± 0.55, P = 0.028; -3.8 ± 7.3 versus 0.95 ± 8.3, P = 0.003 and -2.3 ± 3.7 versus 0.44 ± 7.1 ng/mL, respectively, P < 0.05 for all), even after controlling for changes of QUICKI, FM and waist circumference, remained significant for endothelin-1 and MMP-9 (P = 0.009 and P = 0.005, respectively) but disappeared for E-selectin (P = 0.092). On the contrary, after controlling for serum 25(OH)D, the differences disappeared for endothelin-1(P = 0.066) and MMP-9 (P = 0.277) but still remained significant for E-selectin (P = 0.011).. Ameliorated vitamin D status was accompanied by improved glycemic status, lipid profile and endothelial biomarkers in T2D subjects. Our findings suggest both direct and indirect ameliorating effects of vitamin D on the endothelial biomarkers.. ClinicalTrials.gov: NCT01236846.

Topics: Adult; Aged; Biomarkers; Blood Pressure; Body Mass Index; Cholecalciferol; Diabetes Mellitus, Type 2; Double-Blind Method; E-Selectin; Endothelin-1; Female; Food, Fortified; Humans; Male; Matrix Metalloproteinase 9; Middle Aged; Yogurt

Patients with T2DM have an increased risk of CVD. Prevention of CVD represents the major goal of all treatment of T2DM, and early intervention in those patients at particularly high risk is important.We measured the insulin sensitivity and plasma biomarkers of CVD to determine whether a home-based exercise training program improves biomarker levels and insulin sensitivity. Patients with T2DM (n=12), IGT (n=4) and healthy control subjects (n=9) were studied before and after eight weeks of exercise training by rowing ergometry at 65-70% of peak oxygen uptake.. 1) patients with T2DM have elevated plasma concentrations of CVD biomarkers compared to the matched control and IGT groups; 2) a moderate to vigorous intensity home-based training program did not reduce plasma concentrations of these CVD markers; 3) insulin sensitivity improved as a result of exercise training in the control group, but not in the T2DM group.

Topics: Biomarkers; Blood Glucose; Body Composition; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Endothelin-1; Exercise Therapy; Glucose Tolerance Test; Glycated Hemoglobin; Home Care Services; Humans; Insulin; Intercellular Adhesion Molecule-1; Male; Middle Aged; Oxygen Consumption; Program Evaluation; Time Factors; Treatment Outcome; Vascular Cell Adhesion Molecule-1; von Willebrand Factor

Peroxisome proliferator-activated receptor gamma (PPARgamma) agonists can cause peripheral edema in susceptible individuals. To investigate the mechanistic basis underlying this adverse event, we performed a candidate gene analysis of patients enrolled in clinical trials of muraglitazar, an investigational PPARalpha/gamma dual agonist, and developed a cell culture-based gene expression assay and nonhuman primate model of edema to study the edemagenic properties of PPARgamma agonists.. A total of 213 single nucleotide polymorphisms (SNPs) in 63 genes were genotyped in 730 participants. Chi-square and logistic regression analyses were used to test for association with edema. Transcriptional responses to PPARgamma agonists were evaluated in Calu-6 cells using quantitative real-time PCR. Male Cynomolgus monkeys were treated with PPAR agonists and were evaluated for edema using MRI.. SNPs in renin (rs2368564) and endothelin-1 (rs5370) were associated with reduced risk of edema (P=0.003 and P=0.028, respectively) and an SNP in beta1 adrenergic receptor (rs1801253) was associated with increased susceptibility to edema (P=0.034). Gene expression studies revealed that renin and endothelin-1 were regulated by PPARgamma in Calu-6 cells. A survey of 10 PPARgamma agonists further revealed that a compound's in vitro potency was correlated with its edemagenic potential leading to the prediction that one of three previously uncharacterized PPARgamma agonists would cause less edema. This prediction was validated in a nonhuman primate model of PPARgamma agonist-induced edema.. Our results implicate a key role for renin and endothelin-1 in the edema caused by PPARgamma agonists and demonstrate how knowledge gained from pharmacogenetic studies can be applied in drug discovery.

Topics: Animals; Diabetes Mellitus, Type 2; Edema; Endothelin-1; Female; Gene Expression Regulation; Glycine; Humans; Macaca fascicularis; Male; Oxazoles; Pharmacogenetics; Polymorphism, Single Nucleotide; PPAR gamma; Regression Analysis; Renin

Patients with type 2 diabetes are at considerable risk of excessive morbidity and mortality from cardiovascular disease (CVD). We investigated the clinical effectiveness of Pycnogenol, a flavonoid-rich dietary supplement, in reducing antihypertensive medication use and CVD risk factors in subjects with type 2 diabetes. Forty-eight individuals were enrolled in a randomized, double-blind, placebo-controlled trial with parallel-group design. Patients were diagnosed with both type 2 diabetes and mild to moderate hypertension and were undergoing treatment with angiotensin-converting enzyme (ACE) inhibitors. Subjects were randomly assigned to receive either Pycnogenol pill (125 mg daily) or matched placebo for 12 weeks. According to the values of blood pressure (BP) measured at 2-week intervals, the pretrial ACE inhibitor dosage was left unchanged, reduced by 50%, or brought back to the pretrial dosage until a stable BP was obtained. Fasting plasma glucose, low-density lipoprotein (LDL) cholesterol, glycosylated hemoglobin (HbA1c), serum endothelin-1, and urinary albumin were evaluated monthly. Pycnogenol treatment achieved BP control in 58.3% of subjects at the end of the 12 weeks with 50% reduction in individual pretrial dose of ACE-inhibitors (P <.05). Plasma endothelin-1 decreased by 3.9 pg/mL in Pycnogenol-treated group vs 0.5 pg/mL increase in control group (P < .001). Mean HbA1c dropped by 0.8% in Pycnogenol-treated group (P < .05), whereas it decreased by 0.1% in control group. Fasting plasma glucose declined by 23.7 mg/dL in Pycnogenol-treated group vs 5.7 mg/dL in control group (P < .0001). Low-density lipoprotein cholesterol improved significantly in Pycnogenol-treated group, declining by 12.7 mg/dL (P < .001). A significant decrease in urinary albumin level was observed at week 8 compared with the control group (P < .05). However, this reduction was not significant at 12th week. After 12 weeks of supplementation, Pycnogenol resulted in improved diabetes control, lowered CVD risk factors, and reduced antihypertensive medicine use vs controls.

Topics: Aged; Albumins; Angiotensin-Converting Enzyme Inhibitors; Antioxidants; Blood Glucose; Cardiovascular Diseases; Cholesterol, LDL; Diabetes Mellitus, Type 2; Double-Blind Method; Endothelin-1; Female; Flavonoids; Glycated Hemoglobin; Humans; Hypertension; Hypoglycemic Agents; Male; Middle Aged; Phytotherapy; Pinus; Plant Bark; Plant Extracts

Vascular dysfunction and insulin resistance precede atherosclerosis in type 2 diabetes (T2DM). Better knowledge of the interaction between these is of considerable clinical interest.. The objective of this study was to examine the association between inflammation, glucose, and lipid metabolism and vascular dysfunction.. We conducted a randomized, double-blind, controlled trial of pioglitazone vs. placebo and other therapies aimed at equal glycemic control for 24 wk at an academic tertiary referral clinic.. Mexican-American subjects with T2DM and no complications were randomly assigned to pioglitazone 45 mg daily (PIO, n=16) or placebo (CON, n=15) and matched for age, gender, body mass index, diabetes duration, and glycemic control. All subjects completed the study.. We looked for improved vascular reactivity independent of glycemic control but closely related to plasma adiponectin, lipids, and insulin sensitivity.. After 24 wk, there was an equal decrease in fasting plasma glucose (approximately 135 mg/dl), glycosylated hemoglobin (approximately 7.0%), and glucose production (approximately 15%). The decrease in free fatty acids (30 vs. 10%) and increase in glucose disposal (40 vs. 25%) were greater in PIO vs. CON (P<0.05). In PIO, plasma high-density lipoprotein rose by 15% (P<0.05), and low-density lipoprotein and high-density lipoprotein particle size rose significantly (P<0.01). Plasma adiponectin doubled in PIO (from 6.1+/-0.8 to 12.7+/-2.1 microg/ml). Forearm blood flow rose equally (approximately 130%) during reactive hyperemia in both groups, although after therapy, the increase was greater (P<0.001) in PIO (153%) than in CON (137%); vasodilation was greater (P=0.01) in PIO (92, 160, and 204%) than in CON with acetylcholine (74, 130, and 144%) and with sodium nitroprusside (PIO=164 and 253% vs. 116 and 230%; P=0.04). The elevation in diameter was also greater in PIO (13 vs. 10%; P<0.05). Vascular responses correlated with plasma free fatty acids, adiponectin, and low-density lipoprotein particle size but not with glycemic control.. These data indicate that pioglitazone improves vascular reactivity irrespective of glycemic control and suggest a close association with changes in fat cell metabolism.

Topics: Adiponectin; Body Mass Index; C-Reactive Protein; Diabetes Mellitus, Type 2; Double-Blind Method; Endothelin-1; Female; Hispanic or Latino; Humans; Hypoglycemic Agents; Intercellular Adhesion Molecule-1; Male; Middle Aged; Pioglitazone; Placebos; Thiazolidinediones; Vascular Cell Adhesion Molecule-1

The aim of the present study was to evaluate the effect of prolonged inhibition of beta-oxidation on glucose and lipid muscle forearm metabolism and cGMP and endothelin-1 forearm release in patients with type 2 diabetes mellitus and ischemic cardiomyopathy. Fifteen patients were randomly allocated in a double-blind cross-over parallel study with trimetazidine (20 mg tid) or placebo lasting 15 days. At the end of each period, all patients underwent euglycemic hyperinsulinemic clamps with forearm indirect calorimetry and endothelial balance of vasodilator and vasoconstricor factors. Compared with placebo, trimetazidine induced 1) an increase in insulin-induced forearm glucose uptake and glucose oxidation accompanied by a reduction in forearm lipid oxidation and citrate release and 2) a decrease of endothelin-1 release paralleled by a significant increase in forearm cGMP release. Forearm glucose oxidation significantly correlated with cGMP release (r=0.37, P<0.04), whereas forearm lipid oxidation positively correlated with endothelin-1 release (r=0.40, P<0.03). In conclusion, for the first time, we demonstrated that insulin-induced forearm glucose oxidation and forearm cGMP release were increased whereas forearm endothelin-1 release was decreased during trimetazidine treatment. Muscle's metabolic and vascular effects of trimetazidine add new interest in the use of trimetazidine in type 2 diabetic patients with cardiovascular disease.

Topics: 3-Hydroxybutyric Acid; Aged; Blood Glucose; Citric Acid; Cross-Over Studies; Cyclic GMP; Diabetes Mellitus, Type 2; Double-Blind Method; Endothelin-1; Endothelium, Vascular; Fatty Acids, Nonesterified; Forearm; Glucose; Glucose Clamp Technique; Humans; Insulin; Insulin Resistance; Lipid Metabolism; Male; Middle Aged; Muscle, Skeletal; Myocardial Ischemia; Oxidation-Reduction; Trimetazidine

We investigated the effects of three different daily doses (10 mg, 20 mg, and 40 mg) of atorvastatin, a relatively new and potent statin, on plasma endothelin (ET)-1 and highly sensitive C-reactive protein (CRP) levels in type 2 diabetic subjects. Twenty-nine type 2 diabetic patients with dyslipidemia were enrolled and randomly assigned to receive atorvastatin orally at 10 mg (A10; n = 10), 20 mg (A20; n = 10), or 40 mg (A40; n = 9) daily for 12 weeks. Levels of plasma total cholesterol and low-density lipoprotein (LDL)-cholesterol (C) in all three studied groups were significantly decreased after treatment with atorvastatin for 12 weeks (all groups, P < 0.001). However, the greatest LDL-C lowering effect and the highest percentage of subjects achieving the National Cholesterol Education Program's Adult Treatment Panel III (NCEP-ATP III) LDL-C goal were observed in the A20 group. All diabetic subjects had a higher plasma ET-1 concentration (A10, 1.02 +/- 0.37 pg/ml, mean +/- SD; A20, 1.17 +/- 0.55 pg/ml; and A40, 0.87 +/- 0.45 pg/ml) than that of age- and sex-matched normal control subjects (0.64 +/- 0.15 pg/ml; all groups, P < 0.001). Plasma ET-1 levels showed a borderline significant decrease at the end of study, by 22% in diabetic subjects treated with 10 mg atorvastatin (P = 0.05 compared with baseline), and by 30% in subjects treated with 20 mg atorvastatin (P = 0.06, compared with baseline). Paradoxically, the 40-mg dose of atorvastatin provided an increase of 2% in plasma ET-1 levels at the end of study, which is significantly different (P < 0.05) and marginally significant (P = 0.057) from the levels of the 10- and 20-mg doses, respectively. Similarly, although insignificantly, plasma concentrations of CRP also tended to decrease by 12% and 48%, and paradoxically increased by 18% in diabetic patients treated with 10 mg, 20 mg, and 40 mg atorvastatin, respectively. The clinical significance of these biphasic lipid-independent statin effects is unknown and the present study suggests that 20 mg atorvastatin may have the best benefits in treating diabetic patients with dyslipidemia.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Atorvastatin; Cholesterol; Cholesterol, LDL; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Administration Schedule; Dyslipidemias; Endothelin-1; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Lipoproteins, LDL; Male; Middle Aged; Pyrroles

To investigate the effects and mechanisms of sodium ferutate (SF) in treating diabetic nephropathy (DN).. Eighty patients of diabetes mellitus type 2 with DN were randomly divided into two groups, 40 cases in each group. The routine group treated with conventional treatment including dietary therapy and hypodermic injection of insulin, and the SF group treated with intravenous dripping of SF 300 mg/d additionally besides the conventional therapy, the therapeutic course for both groups was 4 weeks. And 40 healthy volunteers were allocated in a group for normal control. Before and after therapy, levels of fasting blood glucose (FBG), hemoglobin A1c(HbA1c), triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL-C), serum creatinine (SCr), blood urea nitrogen (BUN), mean arterial pressure (MAP), urinary albumin excretion rate (UAER), serum collagen type IV (CIV) and endothelin (ET) were detected.. After 4 weeks of treatment, FBG and HbA1c reduced obviously in both groups with insignificant difference in comparison of them (P > 0.05). Before treatment, TG, TC, MAP, SCr, BUN, UAER, CIV and ET were markedly higher in DN patients than those in the health control (P < 0.05), these criteria decreased significantly in the SF group (P < 0.05) but insignificantly in the routine group (P > 0.05) after treatment, showing difference between the two groups (P < 0.05).. Sodium ferulate could ameliorate lipid metabolic disorder, reduce blood pressure, lower UAER and CIV level, and improve renal function in DN patients, the mechanism might be through decreasing ET production and inhibiting the combining of ET with its receptor.

Topics: Adult; Coumaric Acids; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Drug Therapy, Combination; Drugs, Chinese Herbal; Endothelin-1; Female; Humans; Insulin; Ligusticum; Male; Middle Aged; Phytotherapy

Endothelial dysfunction and inflammation are present in both type 2 diabetes mellitus (T2DM) and obesity. In this paper we compared the role of weight loss and of glycaemic control in determining circulating levels of ICAM-1, endothelin-1 (ET-1), and E-selectin in patients with morbid (grade 3) obesity.. ICAM-1, E-selectin, and ET-1 were higher in obese patients (n=96) than in lean controls (n=30); among obese patients, the three molecules were higher in T2DM patients (n=26) than in patients with normal (NGT, n=43) or impaired (IGT, n=27) glucose tolerance. Sixty-eight obese patients had a significant weight loss induced by bariatric surgery, and showed a significant decrease in blood glucose, HbA1c and all molecules, so that ICAM-1, E-selectin, and ET-1 were not different in NGT, IGT and T2DM patients, and in lean controls; in 13 patients with a small weight loss induced by diet, changes were not significant, in spite of a significant reduction in blood glucose and HbA1c. At stepwise regression, changes in ICAM-1, ET-1, and E-selectin significantly correlated only with change in body mass index.. These data indicate that weight loss is more important than glycaemic control in regulating circulating levels of ICAM-1, ET-1, E-selectin in morbidly obese subjects.

Topics: Adult; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; E-Selectin; Endothelin-1; Female; Follow-Up Studies; Glucose Intolerance; Glycated Hemoglobin; Humans; Insulin Resistance; Intercellular Adhesion Molecule-1; Male; Matched-Pair Analysis; Middle Aged; Obesity, Morbid; Reference Values; Regression Analysis; Weight Loss

To observe the effect of Yiqi Yangyin Huoxue Tongfu (YYHT) principle in treating diabetes mellitus type 2 of secondary failure to sulfonylurea agents.. Forty patients were randomly divided into two groups, based on the unchanged previous treatment of sulfonylurea agents, Chinese decoction prescribed according to YYHT principle was given to the treated group and rosiglitazone was given to the control group. Changes of insulin sensitivity (SI), insulin response to glucose (IRG), insulin sensitive index (ISI), tumor necrosis factor-alpha (TNF-alpha), endothelin-1 (ET-1), 6-keto-prostaglandin F1alpha(6-keto-PGF1alpha) and thromboxane B2 (TXB2) were observed.. The total effective rate in the treated group was 71.4%, that on improving peripheral insulin resistance was 76.2%, the two parameters were similar to those in the control group. In the treated group, SI, ISI were significantly improved, and TNF-alpha, ET-1 and TXB2 significantly lowered, but no change of IRR was found.. Application of YYHT principle in treating patients with diabetes mellitus type 2 of secondary failure to sulfonylurea agents could alleviate the peripheral resistance to insulin, inhibit TNF-alpha, and protect the vascular endothelial cells.

Topics: Adult; Aged; Diabetes Mellitus, Type 2; Drugs, Chinese Herbal; Endothelin-1; Female; Humans; Hypoglycemic Agents; Insulin Resistance; Male; Middle Aged; Phytotherapy; Sulfonylurea Compounds; Tumor Necrosis Factor-alpha; Yin Deficiency

A double-blind, placebo-controlled, randomized, multi-center study was performed with 77 diabetes type II patients to investigate anti-diabetic effects of the French maritime pine bark extract, Pynogenol. Supplementation with 100 mg Pycnogenol for 12 weeks, during which a standard anti-diabetic treatment was continued, significantly lowered plasma glucose levels as compared to placebo. HbA1(c) was also lowered; however, the difference as compared to placebo was statistically significant only for the first month. In the Pycnogenol-group endothelin-1 was significantly decreased, while 6-ketoprostaglandin F(1a) in plasma was elevated compared to placebo. Nitric oxide levels in plasma increased during treatment in both groups, but, differences did not reach statistical significance. Pycnogenol was well-tolerated with ECG, electrolytes, creatinine and blood urea nitrogen remaining unchanged in both groups. Mild and transient unwanted effects were reported for both groups without significant differences. Supplementation of Pycnogenol to conventional diabetes treatment lowers glucose levels and improves endothelial function.

Topics: 6-Ketoprostaglandin F1 alpha; Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Endothelin-1; Female; Flavonoids; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Middle Aged; Phytotherapy; Pinus; Plant Extracts

Endothelial dysfunction may contribute to the risk of premature atherosclerosis in patients with diabetes. Endothelin (ET-1) may be involved in this process by activating smooth muscle cell mitogenesis and leukocyte adhesion. We sought to assess the activity of endogenous ET-1 in a group of patients with type II diabetes mellitus with the use of antagonists of ET-1 receptors.. Forearm blood flow (FBF) responses (strain gauge plethysmography) to intraarterial infusion of a selective blocker of ET(A) receptors (BQ-123) and, on a different occasion, to ET-1, were measured in 15 patients with diabetes and 12 healthy controls. In addition, 5 patients with diabetes received coinfusion of BQ-123 and BQ-788 (a selective blocker of ET(B) receptors). In normal subjects, BQ-123 did not significantly modify FBF from baseline (P=0.16). In contrast, BQ-123 administration resulted in a significant vasodilator response in patients with diabetes (P<0.001). Infusion of exogenous ET-1 resulted in lower vasoconstrictor responses in patients with diabetes than in controls (P=0.001), whereas the vasoconstrictor response to norepinephrine was similar in the 2 groups (P=0.78). In patients with diabetes, the vasodilator response to selective ET(A) blockade was not significantly modified by nonselective blockade of ET-1 receptors obtained by coinfusion of BQ-123 and BQ-788.. The activity of endogenous ET-1 on ET(A) receptors is enhanced in the resistance vessels of patients with diabetes, whereas their sensitivity to exogenous ET-1 is blunted. This abnormality may participate in the pathophysiology of vascular complications associated with diabetes.

Topics: Blood Flow Velocity; Blood Pressure; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Endothelin Receptor Antagonists; Endothelin-1; Endothelins; Female; Forearm; Heart Rate; Humans; Infusions, Intra-Arterial; Male; Middle Aged; Norepinephrine; Oligopeptides; Peptides, Cyclic; Piperidines; Receptor, Endothelin A; Receptor, Endothelin B; Reference Values; Regional Blood Flow; Vascular Resistance; Vasomotor System

The aims of this study were to elucidate the factors that contribute to endothelial activation and fibrinolytic abnormalities in patients with poorly controlled type 2 diabetes and to determine whether improved glycemic control reduces endothelial activation. Adhesion molecules [E-selectin, intracellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1], von Willebrand factor, total nitric oxide (NO), endothelin-1, tissue plasminogen activator, and plasminogen activator inhibitor-1 were measured in 43 type 2 diabetic subjects with hemoglobin A1c of 9.0% or more at baseline (compared with 21 healthy controls) who after 20 wk had been randomized to either improved (IC) or usual (UC) glycemic control. At baseline, type 2 diabetic patients had significant endothelial activation and abnormal fibrinolysis compared with control subjects. Body mass index in the diabetic patients was the only independent predictor of E-selectin (P = 0.007), ICAM-1 (P = 0.01), and NO (P = 0.008) concentrations, but not vascular cell adhesion molecule-1, plasminogen activator inhibitor-1, or tissue plasminogen activator (all P > 0.05). Type 2 diabetic patients with a body mass index of 28 kg/m2 or less had concentrations of E-selectin, ICAM-1, endothelin-1, and NO similar to those in healthy controls. After 20 wk, hemoglobin A1c was significantly lower in IC vs. UC (IC, 8.02 +/- 0.25%; UC, 10.23 +/- 0.23%; P < 0.0001), but there were no significant changes in markers of endothelial activation or indexes of fibrinolysis. Obesity appears to be the most important predictor of endothelial activation in patients with type 2 diabetes. Short-term improvement in glycemic control does not appear to reduce endothelial activation.

Topics: Biomarkers; Blood Glucose; Cell Adhesion Molecules; Diabetes Mellitus, Type 2; Electrocardiography; Endothelin-1; Endothelium, Vascular; Female; Fibrinolysis; Humans; Hypoglycemic Agents; Male; Middle Aged; Models, Biological; Nitric Oxide; Obesity; Regression Analysis

The purpose of the study was to examine the relationship between the endothelin-1 (ET-1) concentration and the metabolic variables characteristic of the insulin resistance syndrome ([IRS] hyperinsulinemia, insulin resistance, hypertriglyceridemia, low high-density lipoprotein [HDL] cholesterol, visceral obesity, and glycemic abnormalities). The measurement of circulating ET-1 is a well-recognized marker of endothelial atherosclerotic and cardiovascular disease. Two hundred subjects were divided into 3 groups. Group 1 included 50 subjects with impaired glucose tolerance (IGT) or non-insulin-dependent diabetes mellitus (NIDDM) with IRS. Group 2 included 50 subjects with IGT or NIDDM without IRS. Group 3 included 100 normal subjects as controls. ET-1 levels were higher in group 1 versus groups 2 and 3 in women (11.2 +/- 0.7 v 7.9 +/- 0.5 and 6.6 +/- 0.4 pg/mL, P < .01) and men (10.1 +/- 0.6 v 6.5 +/- 0.8 and 7.2 +/- 0.3 pg/mL, P < .01). No differences were found between groups 2 and 3. With simple regression analysis, ET-1 levels significantly correlated with insulin, glycosylated hemoglobin, body weight, waist to hip ratio, and triglyceride values. However, with multiple regression analysis, only triglycerides (P < .009) and glycosylated hemoglobin (P < .001) remained independently correlated with ET-1. In conclusion, this cross-sectional study indicates that glycosylated hemoglobin and triglycerides are independently correlated with ET-1 levels in patients with IRS.

Topics: Blood Glucose; Body Weight; Cholesterol; Diabetes Mellitus, Type 2; Endothelin-1; Female; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Insulin Resistance; Male; Middle Aged; Regression Analysis; Triglycerides

The haemodynamic hypothesis for the pathogenesis of diabetic microangiopathy argues that an initial increase in microvascular blood flow leads to microvascular sclerosis and disturbed autoregulation. Endothelin-1 (ET-1) is an endothelium-derived vasoconstrictor peptide that contributes to basal vascular tone. Impairment of the vasoconstrictor response to ET-1 could result in hyperperfusion and subsequent microvascular damage. The purpose of this study was to determine whether vascular responses to ET-1 are impaired in patients with non-insulin-dependent diabetes mellitus (type 2 diabetes). Ten patients with type 2 diabetes and nine control subjects underwent brachial artery cannulation. Forearm blood flow was measured using strain-gauge venous occlusion plethysmography. ET-1 in three doses of 5, 10, and 20 pmol/min and 0.9% saline placebo was infused in a balanced double-blind randomised manner. Vascular smooth muscle function also was assessed using sodium nitroprusside. Control subjects showed vasoconstriction to ET-1 of 5 (p < 0.05), 10 (p < 0.05), and 20 pmol/min (p < 0.01). In the diabetic group, there was no significant response to ET-1 at 5 pmol/min (p > 0.05); however, significant vasoconstriction developed at 10 and 20 pmol/min (p < 0.01). There was a significant difference in response to ET-1 at 5 pmol/min between the diabetic and control groups (p < 0.05). Responses to sodium nitroprusside were similar in both groups (p > 0.05). Patients with type 2 diabetes have a blunted vasoconstrictor response to ET-1 despite preserved vascular smooth muscle function.

Topics: Adult; Aged; Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Endothelin-1; Female; Forearm; Humans; Male; Middle Aged; Regional Blood Flow; Vasoconstriction

Type 2 diabetes and metabolic syndrome are major cardiovascular risk factors in postmenopausal women, but the role of vasoconstrictive endothelin-1 (ET-1) in these conditions is not known. We studied the levels of ET-1 and the effect of postmenopausal hormonal therapy on ET-1 levels in postmenopausal women.. We compared plasma levels of ET-1 in 22 postmenopausal type 2 diabetic women and 14 postmenopausal women with metabolic syndrome with plasma levels in 10 healthy postmenopausal control women. The basal values for ET-1 were measured for all groups. These women were then randomised to receive in a double-dummy, crossover trial: either oral continuous oestradiol (2.0 mg) + norethisterone acetate (1.0 mg) per day or continuous transdermal oestrogen-only (50 mg/day) for 3 months. Between the active therapy there were 3-month wash-out periods. ET-1-values were measured again at the end of each treatment period.. The type 2 diabetic women had significantly (p < 0.003) elevated ET-1 levels (4.8+/-1.0 pg/ml) whereas those with metabolic syndrome (4.4+/-1.7 pg/ml]) had non-significantly (NS) elevated ET-1 levels compared to controls (3.6+/-0.3 pg/ml). Both oral and transdermal hormone replacement therapy (HRT) failed to affect plasma ET-1 except in 14 hypertensive women from the diabetes and metabolic syndrome groups who were on angiotensin convertase enzyme (ACE) inhibitors. These women's ET-1 levels before oral HRT (4.6+/-1.1 pg/ml) fell to 4.1+/-0.9 pg/ml (p < 0.05).. Type 2 diabetes in postmenopausal women is associated with elevated ET-1 levels. Oestrogen replacement therapy does not affect the levels of ET-1 in postmenopausal women with type 2 diabetes or metabolic syndrome.

Topics: Administration, Cutaneous; Administration, Oral; Biomarkers; Body Constitution; Body Mass Index; Cholesterol, HDL; Cross-Over Studies; Diabetes Mellitus, Type 2; Endothelin-1; Estradiol; Estrogen Replacement Therapy; Female; Humans; Hyperlipidemias; Hypertension; Middle Aged; Norethindrone; Norethindrone Acetate; Postmenopause; Reference Values; Syndrome; Triglycerides

Microvascular alterations, impairment of coagulation, ischemia and diffuse endothelial damage are related to the progression of diabetic retinopathy. Defibrotide has been demonstrated to produce profibrinolytic, cytoprotective and vasofacilatory activities. The aim of the present study was to evaluate the therapeutic effect of Defibrotide in the treatment of nonproliferative diabetic retinopathy.. Two randomized age- and sex-matched groups (cases and controls) of 35 NIDDM patients presenting non-proliferative diabetic retinopathy were included in this study: cases were treated with Defibrotide (800-1600 mg daily) for two years.. All tested parameters (ETDRS visual acuity; computerized perimetry; retinography; fluorescein angiography), improved significantly (p<0.001) in Defibrotide-treated patients compared to controls. In our opinion, Defibrotide's manifold effects on vascular endothelia may account for this improvement by stimulation of tPA, PGI2, PGE2, thrombomodulin and modulation of endothelin-1 release.. Our preliminary data seem to suggest that Defibrotide could be proposed for medical treatment of nonproliferative diabetic retinopathy.

Topics: Aged; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Dinoprostone; Endothelin-1; Endothelium, Vascular; Epoprostenol; Female; Fibrinolytic Agents; Fluorescein Angiography; Follow-Up Studies; Fundus Oculi; Humans; Male; Middle Aged; Pilot Projects; Polydeoxyribonucleotides; Retina; Thrombomodulin; Tissue Plasminogen Activator; Treatment Outcome; Visual Field Tests

To examine a possible role for endothelin-1 in the pathophysiology of diabetic microangiopathy, we measured plasma levels of endothelin-1 and big endothelin-1, a precursor peptide of endothelin-1, in 33 untreated patients with non-insulin-dependent diabetes mellitus. There was no significant difference among the mean plasma endothelin-1 concentrations in 18 patients with microangiopathy, in 15 patients without microangiopathy and in 33 age-matched normal subjects. In contrast, the mean plasma big endothelin-1 concentration in patients with microangiopathy was significantly higher than in those without microangiopathy or in normal subjects. As a consequence, the mean big endothelin-1 to endothelin-1 ratio in patients with microangiopathy was significantly higher than in the other two groups. There was no significant correlation between plasma levels of endothelin-1 or big endothelin-1 and fasting blood glucose, HbA1c, mean blood pressure, or period of duration of diabetes mellitus in the patient groups. The results indicate that elevation of plasma big endothelin-1 levels with diminished conversion of big endothelin-1 to endothelin-1 is associated with diabetic microangiopathy, which may be the effect rather than the cause of endothelial dysfunction.

Topics: Adult; Blood Glucose; Blood Pressure; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Endothelin-1; Endothelins; Female; Glycated Hemoglobin; Humans; Male; Middle Aged; Protein Precursors; Time Factors

Diabetes and sarcopenia are verified as mutual relationships, which seriously affect the quality of life of the elderly. Endothelin-1 is well investigated, is elevated in patients with diabetes, and is related to muscle cellular senescence and fibrosis. However, the mechanism of ET-1 between diabetes and myopathy is still unclear. The aim of this study was to evaluate the prevalence of sarcopenia in the elderly with diabetes and to clarify its relationship with ET-1 molecular biological mechanism, progress as well as changes in muscle and fat.. We recruited 157 type 2 diabetes patients over 55 years old and investigated the prevalence of sarcopenia in diabetes patients and examined the association of ET-1 alterations with HbA1c, creatinine, or AMS/ht2. Next, sought to determine how ET-1 regulates inflammation in muscle cells by western blot and qPCR assay. Using XF Seahorse Technology, we directly quantified mitochondrial bioenergetics in 3T3-L1 cells.. ET-1 was positively correlated with HbA1c, creatinine levels, and duration of disease, and negatively correlated with AMS/ht2. We found that ET-1 dose-dependently induces tumor necrosis factor-α (TNF-α) and interleukin (IL)-6β expression through the PI3K/AKT, and NF-κB signaling pathways in C2C12 cells. Also identified that TNF-α, IL-6β, and visfatin releases were found in co-cultured with conditioned medium of ET-1/C2C12 in 3T3-L1 cells. ET-1 also reduces the energy metabolism of fat and induces micro-environment inflammation which causes myopathy. ET-1 also suppresses miR-let-7g-5p expression in myocytes and adipocytes.. We describe a new mechanism of ET-1 triggering chronic inflammation in patients with hyperglycemia.

Topics: Aged; Creatinine; Diabetes Mellitus, Type 2; Endothelin-1; Glycated Hemoglobin; Humans; Inflammation; MicroRNAs; Muscular Diseases; Phosphatidylinositol 3-Kinases; Quality of Life; Sarcopenia; Tumor Necrosis Factor-alpha

Endothelin-1 (ET-1) and adrenomedullin (ADM) are commonly known as vasoactive peptides that regulate vascular homeostasis. Less recognised is the fact that both peptides could affect glucose metabolism. Here, we investigated whether ET-1 and ADM, measured as C-terminal-proET-1 (CT-proET-1) and mid-regional-proADM (MR-proADM), respectively, were associated with incident type 2 diabetes.. Based on the population-based Biomarkers for Cardiovascular Risk Assessment in Europe (BiomarCaRE) Consortium data, we performed a prospective cohort study to examine associations of CT-proET-1 and MR-proADM with incident type 2 diabetes in 12,006 participants. During a median follow-up time of 13.8 years, 862 participants developed type 2 diabetes. The associations were examined in Cox proportional hazard models. Additionally, we performed two-sample Mendelian randomisation analyses using published data.. CT-proET-1 and MR-proADM were positively associated with incident type 2 diabetes. The multivariable hazard ratios (HRs) [95% confidence intervals (CI)] were 1.10 [1.03; 1.18], P = 0.008 per 1-SD increase of CT-proET-1 and 1.11 [1.02; 1.21], P = 0.016 per 1-SD increase of log MR-proADM, respectively. We observed a stronger association of MR-proADM with incident type 2 diabetes in obese than in non-obese individuals (P-interaction with BMI < 0.001). The HRs [95%CIs] were 1.19 [1.05; 1.34], P = 0.005 and 1.02 [0.90; 1.15], P = 0.741 in obese and non-obese individuals, respectively. Our Mendelian randomisation analyses yielded a significant association of CT-proET-1, but not of MR-proADM with type 2 diabetes risk.. Higher concentrations of CT-proET-1 and MR-proADM are associated with incident type 2 diabetes, but our Mendelian randomisation analysis suggests a probable causal link for CT-proET-1 only. The association of MR-proADM seems to be modified by body composition.

Topics: Adrenomedullin; Biomarkers; Diabetes Mellitus, Type 2; Endothelin-1; Heart Disease Risk Factors; Humans; Obesity; Peptide Fragments; Prospective Studies; Protein Precursors

Diabetic peripheral neuropathy (DPN) is a common microvascular complication in patients with type 2 diabetes (T2D). Apart from hyperglycemia, few modifiable risk factors have been identified. Endothelin-1 is a potent vasoconstrictor peptide, implicated in the causal pathway of microangiopathy. We investigated whether baseline plasma endothelin-1 and other metabolic and vascular risk factors predicted the incidence of DPN.. This is a 3-year observational, cohort study.. In patients with T2D (n = 2057), anthropometric data, fasting blood, and urine were collected for biochemistry and urine albumin/creatinine measurements. Forearm cutaneous endothelial reactivity was assessed by iontophoresis and laser Doppler flowmetry/imaging. Measurements were repeated on follow-up. Incident DPN was considered present if an abnormal finding in monofilament (<8 of 10 points) or neurothesiometer testing was ≥25 volts on either foot at 3-year follow-up, but normal at baseline. Plasma endothelin-1 was assessed by ELISA.. At baseline, mean age of patients was 57.4 ± 10.8 years old and prevalence of DPN was 10.8%. Of the 1767 patients without DPN, 1250 patients returned for follow-up assessment ((2.9 ± 0.7) years), with a 10.7% incidence of DPN. Patients with incident DPN had significantly higher baseline endothelin-1 (1.43 (1.19-1.73) vs 1.30 (1.06-1.63)) pg/mL, P < 0.0001. Multivariable Cox proportional hazards ratio showed a 1-s.d. increase in log endothelin-1 (adjusted HR: 4.345 (1.451-13.009), P = 0.009), systolic blood pressure (per 10-unit) (adjusted HR: 1.107 (1.001-1.223), P = 0.047) and diabetes duration (adjusted HR: 1.025 (1.004-1.047), P = 0.017) predicted incident DPN, after adjustment for glycemic control, eGFR, albuminuria, peripheral arterial disease and retinopathy status.. Higher baseline endothelin-1, blood pressure and diabetes duration were significant and independent predictors for incident DPN. Validation of our findings in independent cohorts and molecular mechanistic studies will help better our understanding on the role of endothelin-1 in DPN.

Topics: Aged; Blood Pressure; Cohort Studies; Diabetes Mellitus, Type 2; Diabetic Neuropathies; Endothelin-1; Female; Humans; Incidence; Male; Middle Aged; Prevalence; Proportional Hazards Models; Risk Factors

Previous evidence has implied that obesity is an independent risk factor for developing cancer. Being closely related to obesity, type 2 diabetes mellitus provides a suitable environment for the formation and metastasis of tumors through multiple pathways. Although bariatric surgeries are effective in preventing and lowering the risk of various types of cancer, the underlying mechanisms of this effect are not clearly elucidated.. To uncover the role and effect of sleeve gastrectomy (SG) in preventing lung cancer in obese and diabetic rats.. SG was performed on obese and diabetic Wistar rats, and the postoperative transcriptional and translational alterations of the endothelin-1 (ET-1) axis in the lungs were compared to sham-operated obese and diabetic rats and age-matched healthy controls to assess the improvements in endothelial function and risk of developing lung cancer at the postoperative 4. Compared to obese and diabetic sham-operated rats, SG brought a significant reduction to body weight, food intake, and fasting blood glucose while improving oral glucose tolerance and insulin sensitivity. In addition, ameliorated levels of gene and protein expression in the ET-1 axis as well as reduced DNA damage indicated improved endothelial function and a lower risk of developing lung cancer after the surgery.. Apart from eliminating metabolic disorders, SG improves endothelial function and plays a protective role in preventing lung cancer

Topics: Animals; Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; DNA Breaks, Double-Stranded; Endothelin-1; Endothelium; Glucose Tolerance Test; Histones; Humans; Lung; Lung Neoplasms; Male; Obesity; Phosphoproteins; Phosphorylation; Rats; Streptozocin; Weight Loss

Activation of the vascular endothelin-1 (ET-1) system is a key abnormality in vascular dysfunction of human obesity, especially in patients developing complications, such as the metabolic syndrome, diabetes, and atherosclerosis. Vascular insulin resistance, an increased insulin-stimulated endothelial production of ET-1 combined with impaired nitric oxide availability, is the hallmark of obesity-related vasculopathy, but dysregulated adipokine release from obese adipose tissue may contribute to the predominance of ET-1-dependent vasoconstriction. ET-1, in turn, might determine unhealthy obese adipose tissue expansion, with visceral and perivascular adipose tissue changes driving the release of inflammatory cytokines and atherogenic chemokines. In addition, ET-1 might also play a role in the development of the metabolic complications of obesity. Studies have shown inhibition of lipoprotein lipase activity by ET-1, with consequent hypertriglyceridemia. Also, ET-1 in pancreatic islets seems to contribute to beta cell dysfunction, hence affecting insulin production and development of diabetes. Moreover, ET-1 may play a role in nonalcoholic steatohepatitis. Recent clinical trials using innovative design have demonstrated that antagonism of ET-type A receptors protects against some complications of obesity and diabetes, such as nephropathy. These findings encourage further investigation to evaluate whether targeting the ET-1 system could afford better protection against other consequences of the obesity epidemic.

Topics: Adipokines; Adipose Tissue; Cytokines; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelin Receptor Antagonists; Endothelin-1; Endothelium, Vascular; Humans; Insulin; Insulin Resistance; Insulin-Secreting Cells; Non-alcoholic Fatty Liver Disease; Obesity; Receptor, Endothelin A; Vasoconstriction

Mitochondria play a central role in the regulation of energy metabolism, and the biogenesis of mitochondria is enhanced by the action of nitric oxide (NO), which is the key signaling molecule in the regulation of vascular homeostasis. A disturbance in the regulation of energy metabolism can be a key reason for the formation of insulin resistance and type 2 diabetes mellitus. Moreover, mitochondrial dysfunction leads to oxidative stress, which increases the production of proinflammatory cytokines. In this regard, the aim of this study was to identify the relationship of the copy number of mtDNA in adipose tissue from different locations (subcutaneous adipose tissue (SAT), mesentery (Mes), greater omentum (GO)), liver biopsy samples and mononuclear blood cells (MNCs) with endothelial dysfunction markers (eNOS, ET-1, iCAM-1, vCAM-1, VEGF) and inflammatory mediators (TNF-α, IL-6, IL-8, CRP, leptin) in obese patients (body mass index (BMI) > 35 kg/m. The study included 88 obese patients (BMI > 35 kg/m2) treated at the Kaliningrad Region Hospital. The control group consisted of 20 healthy donors. To measure mtDNA copy number we used droplet digital PCR. The concentrations of molecules (TNF-α, IL-6, IL-8, VEGF, eNOS, ET-1, iCAM-1, vCAM-1, VEGF) were measured in plasma using the following sandwich enzyme-linked immunosorbent assays (ELISAs). Quantitative determination of leptin was evaluated by flow-fluorimetry on a «Bio-Plex Protein Assay System». Statistical analysis and graphs were obtained in R Statistical Software (version 3.3.1).. The systemic character of chronic subclinical inflammation in obesity is established, and an increase in the level of endothelial dysfunction molecules was observed in the blood plasma. The levels of TNF-a, IL-6, and IL-8 were positively correlated with increases in BMI, serum glucose and cholesterol levels.. The copy number of mtDNA in various fat stores was higher in obese patients with type 2 diabetes than in obese patients without diabetes or in the control subjects and was related to the levels of leptin and proinflammatory cytokines.

Topics: Adipose Tissue; Biomarkers; Body Mass Index; Case-Control Studies; Cholesterol; Diabetes Mellitus, Type 2; DNA Copy Number Variations; DNA, Mitochondrial; Endothelin-1; Humans; Intercellular Adhesion Molecule-1; Leptin; Obesity; Tumor Necrosis Factor-alpha

Previous studies have demonstrated that excess aldosterone impairs glucose metabolism. However, the underlying mechanism is still misty. Aldosterone has been proved a risk factor of fibrosis and inflammation. And the histology of islets from patients with type 2 diabetes (T2D) also displays inflammation and fibrosis. But it is unclear whether aldosterone has direct impact on islet inflammation and fibrosis in T2D. Islet endothelium plays a significant role in the maintenance of islet beta cell function and has a close relationship with islet fibrosis and inflammation. Therefore, we focused on the effect of aldosterone on the islet endothelium. In this study, we utilized a diabetic db/db mouse model and examined serum aldosterone levels, islet macrophages infiltration, and islet fibrosis. After we confirmed that there was an increased expression of intercellular cell adhesion molecule-1 (ICAM-1) and endothelin-1 (ET-1) in islet of diabetic mice compared with wild type mice. We next determined that aldosterone increased expression of ICAM-1 and ET-1 in both mRNA and protein levels in islet endothelium in vitro. And then we tested the expression of mineralocorticoid receptor (MR) in islet endothelium in vitro and in vivo. Our results showed that aldosterone can up-regulate the expression levels of ICAM-1 and ET-1 through MR. These findings suggest excess aldosterone might participate in islet inflammation and fibrosis in T2D.

Topics: Aldosterone; Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Progression; Endothelin-1; Endothelium; Fibrosis; Inflammation; Intercellular Adhesion Molecule-1; Islets of Langerhans; Mice; Up-Regulation

The aim of this study was to determine if weight loss following Roux-en-Y gastric bypass (RYGB) surgery in morbidly obese patients is associated with a decrease in plasma concentrations of neprilysin, mediators of the renin angiotensin system (RAS), catecholamines and endothelin-1, and also with an increase in the concentrations of vasodilators. Fasting blood samples were obtained from 15 patients with morbid obesity and diabetes prior to and 6 months after RYGB surgery. Circulating levels of neprilysin, vasoconstrictors, vasodilators, and the mRNA expression of related genes in circulating mononuclear cells (MNC) were measured. Six months after RYGB surgery the concentrations of neprilysin, angiotensinogen, angiotensin II, renin and endothelin-1 fell significantly by 27 ±16%, 22 ±10%, 22 ±8%, 35 ±13% and 17 ±6% (P < .05 for all), respectively, while ANP concentrations increased significantly by 24 ±13%. There was no significant change in aldosterone, BNP, cAMP or cGMP concentrations, or angiotensin converting enzyme (ACE) expression. These changes may contribute to the reduction of congestive cardiac failure and blood pressure risks after RYGB surgery.

Topics: Bariatric Surgery; Body Mass Index; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Cardiomyopathies; Endothelin-1; Female; Glycated Hemoglobin; Heart Failure; Humans; Hypertension; Insulin Resistance; Male; Middle Aged; Neprilysin; Obesity, Morbid; Postoperative Period; Prospective Studies; Renin-Angiotensin System; Risk; Weight Loss

BACKGROUND No-reflow phenomenon is a well-known problem, often accompanying percutaneous coronary intervention (PCI) for ST-segment elevation acute myocardial infarction (STEAMI). This study investigated the value of plasma D-dimer and Endothelin-1 (ET-1) levels on admission in predicting no-reflow after primary PCI and long-term prognosis in STEAMI patients with type 2 diabetes mellitus (T2DM). MATERIAL AND METHODS There were 822 patients with STEAMI and T2DM undergoing successful primary PCI included in this study: 418 patients showed normal re-flow after PCI, while 404 patients showed no-reflow phenomenon after PCI. The predictive value of plasma ET-1 and D-dimer level, and other clinical parameters for the no-reflow phenomenon were analyzed. RESULTS The high plasma ET-1 and D-dimer levels showed predictive value for the no-reflow phenomenon in STEAMI patients with T2DM. Patients with high D-dimer and ET-1 levels showed higher risk (4.212, with 95%CI of 2.973-5.967 and 2.447 with 95%CI of 1.723-3.476, respectively) of no-reflow phenomenon compared with patients with low plasma D-dimer and ET-1 levels. Sensitivity of high plasma ET-1 and D-dimer levels in predicting no-reflow was 0.766. Both plasma D-dimer and ET-1 were adverse prognosticators for STEAMI patients with a T2DM post PCI (P<0.001). CONCLUSIONS In conclusion, plasma D-dimer and ET-1 levels on admission independently predict no-reflow after PCI in STEAMI patients with T2DM. When combined, the D-dimer and ET-1 levels as predictive and prognostic values are clinically promising. The plasma D-dimer and ET-1 levels provided a novel marker for treatment selection for the STEAIM patients with a T2DM history.

Topics: Diabetes Mellitus, Type 2; Endothelin-1; Female; Fibrin Fibrinogen Degradation Products; Humans; Male; Middle Aged; Multivariate Analysis; No-Reflow Phenomenon; Percutaneous Coronary Intervention; Prognosis; ROC Curve; Sensitivity and Specificity; ST Elevation Myocardial Infarction

to evaluate the role of clinical characteristics, functional markers of vasodilation, inflammatory response, and atherosclerosis in predicting wound healing in diabetic foot ulcer.. a cohort study (February - October 2010) was conducted from 40 subjects with acute diabetic foot ulcer at clinical ward of Dr. Cipto Mangunkusumo National Central General Hospital, Jakarta, Indonesia. Each subject underwent at least two variable measurements, i.e. during inflammatory phase and proliferation phase. The studied variables were clinical characteristics, complete peripheral blood count (CBC) and differential count, levels of HbA1c, ureum, creatinine, lipid profile, fasting blood glucose (FBG), marker of endothelial dysfunction (asymmetric dimethylarginine/ADMA, endothelin-1/ET-1, and flow-mediated dilation/FMD of brachial artery), and marker of vascular calcification (osteoprotegerin/OPG).. median of time achieving 50% granulation tissue in our study was 21 days. There were nine factors that contribute in the development of 50% granulation tissue, i.e. family history of diabetes mellitus (DM), previous history of wound, wound area, duration of existing wound, captopril and simvastatin medications, levels of ADMA, ET-1, and OPG. There were three out of the nine factors that significantly correlated with wound healing, i.e. wound area, OPG levels, and simvastatin medications.. in acute diabetic foot ulcers, wound area and OPG levels had positive correlation with wound healing, whereas simvastatin medications had negative correlation with wound healing.

Topics: Aged; Biomarkers; Cohort Studies; Diabetes Mellitus, Type 2; Diabetic Foot; Endothelin-1; Female; Humans; Indonesia; Kaplan-Meier Estimate; Linear Models; Male; Middle Aged; Multivariate Analysis; Osteoprotegerin; Tertiary Care Centers; Vascular Calcification; Wound Healing

PurposeThe purpose of this study was to determine the association between aqueous ET-1 levels and total retinal blood flow (TRBF) in patients with non-insulin-dependent type 2 diabetes mellitus (T2DM) and early non-proliferative diabetic retinopathy (NPDR).Patients and methodsA total of 15 age-matched controls and 15 T2DM patients with NPDR were recruited into the study. Aqueous humor (~80-120 μl) was collected before cataract surgery to measure the levels of ET-1 using suspension multiplex array technology. Four weeks post surgery, six images were acquired to assess TRBF using the prototype RTVue Doppler FD-OCT (Optovue, Inc., Fremont, CA, USA) with a double circular scan protocol. At the same visit, forearm blood was collected to determine plasma glycosylated hemoglobin (A1c) levels.ResultsAqueous ET-1 was significantly elevated in the NPDR group compared with the control group (3.5±1.8 vs 2.2±0.8, P=0.02). TRBF was found to be significantly reduced in the NPDR group compared with the control group (34.5±9.1 vs 44.1±4.6 μl/min, P=0.002). TRBF and aqueous ET-1 were not correlated within the NPDR group (r=-0.24, P=0.22). In a multivariate analysis, high A1c was associated with reduced TRBF and aqueous ET-1 levels across control and NPDR groups (P<0.01).ConclusionAqueous ET-1 levels were increased while TRBF was reduced in patients with NPDR compared with the control group. Although not directly associated, the vasoconstrictory effects of ET-1 are consistent with a reduced TRBF observed in early DR. ET-1 dysregulation may contribute to a reduction in retinal blood flow during early DR.

Topics: Aged; Aqueous Humor; Biomarkers; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Endothelin-1; Female; Humans; Male; Regional Blood Flow; Retinal Vessels; Tomography, Optical Coherence

To determine the effect of adiponectin (APN) on the coronary no-reflow (NR) injury in rats with Type 2 diabetes mellitus (T2DM), 80 male Sprague-Dawley rats were fed with a high-sugar-high-fat diet to build a T2DM model. Rats received vehicle or APN in the last week and then were subjected to myocardial ischemia reperfusion (MI/R) injury. Endothelium-dependent vasorelaxation of the thoracic aorta was significantly decreased and serum levels of endothelin-1 (ET-1), intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were noticably increased in T2DM rats compared with rats without T2DM. Serum APN was positively correlated with the endothelium-dependent vasorelaxation, but negatively correlated with the serum level of ET-1. Treatment with APN improved T2DM-induced endothelium-dependent vasorelaxation, recovered cardiac function, and decreased both NR size and the levels of ET-1, ICAM-1 and VCAM-1. Hypoadiponectinemia was associated with the aggravation of coronary NR in T2DM rats. APN could alleviate coronary NR injury in T2DM rats by protecting the endothelium and improving microcirculation.

Topics: Adiponectin; Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Intercellular Adhesion Molecule-1; Male; No-Reflow Phenomenon; Rats; Rats, Sprague-Dawley; Vascular Cell Adhesion Molecule-1

This study aimed to screen microRNAs and their corresponding target genes that are associated with vascular injury in type two diabetes mellitus (T2DM), investigate the effects of differentially expressed miRNAs and their target genes on high glucose-induced vascular injury and establish the mechanism underlying these effects.. A high-throughput digital gene expression (DGE) sequencing was performed to sequence microRNAs (miRNAs) and messenger RNAs (mRNAs) and determine their differential expression in human umbilical vein endothelial cells (HUVECs) incubated with serum samples from patients with T2DM and healthy volunteers. The HUVECs were transfected with si-TNF-α (tumor necrosis factor α) and a miR-149-5p inhibitor or mimic in vitro and then treated with normal or high glucose. The relative content of nitric oxide (NO) in the cells was detected using the Griess Reagent System. The mRNA and protein expression of endothelial nitric oxide synthase (eNOS) were determined by qRT-PCR and Western blotting. The content of endothelin-1 (ET-1), von Willebrand factor (vWF), and intercellular adhesion molecular-1 (ICAM-1) were detected using an enzyme-linked immunosorbent assay (ELISA) kit. Apoptosis was determined by flow cytometry using the Annexin V/PI apoptosis detection kit. The mRNA and protein expression levels of ER stress (ERS) markers were determined by qRT-PCR and Western blotting.. Based on the high-energy sequencing and in vitro pre-experiment studies, we determined that miR-149-5p and TNF-α were a differentially expressed mRNA/miRNA pair in T2DM with vascular injury. The luciferase reporter assay results demonstrated that miR-149-5p could directly target TNF-α. The upregulation of miR-149-5p reduced the high glucose-induced dysfunction in the HUVECs by significantly decreasing the levels of ET-1, vWF, and ICAM-1 and increasing the level of NO and the expression of eNOS. Additionally, we found that miR-149-5p can improve cell injury and reduce apoptosis by restoring the ameliorated high glucose-induced expression of ERS markers.. TNF-α and miR-149-5p were differentially expressed in T2DM vascular endothelial injury. The over-expression of miR-149-5p ameliorates the high glucose-induced injury in the HUVECs by regulating the expression of TNF-α and ERS markers.

Topics: Adult; Aged; Antagomirs; Apoptosis; Blood Glucose; Diabetes Mellitus, Type 2; Endoplasmic Reticulum Stress; Endothelin-1; Gene Expression Regulation; Glucose; Human Umbilical Vein Endothelial Cells; Humans; Intercellular Adhesion Molecule-1; MicroRNAs; Middle Aged; Nitric Oxide; Nitric Oxide Synthase Type III; RNA, Messenger; Tumor Necrosis Factor-alpha; von Willebrand Factor

Diabetic nephropathy (DN) is a major microvascular complication of type 2 diabetes mellitus (T2DM). Several lines of evidence implicate the endothelin (ET) system in the pathophysiology of DN. The aim of the present study was to analyze if genetic polymorphisms of the ET-1 (EDN1) gene affect susceptibility to DN in Caucasians with T2DM.. The study population consisted of 651 Caucasian subjects with T2DM of more than 10 years' duration: 276 patients with DN (cases) and 375 patients without evidence of DN (controls). Polymorphisms in ET-1 (EDN1) gene, rs5370, rs1476046, and rs3087459, were studied.. Genotype distributions of the studied polymorphisms showed no significant difference between cases and controls.. We provide evidence that the rs5370, rs1476046, and rs3087459 polymorphisms of EDN1 gene are not risk factors for DN in Caucasians with T2DM.

Topics: Adult; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelin-1; Female; Genetic Predisposition to Disease; Humans; Male; Middle Aged; Polymorphism, Genetic; Reference Values; Retrospective Studies; Risk Assessment; Sensitivity and Specificity; White People

Although impairments in endothelial signaling are hypothesized to reduce insulin-stimulated blood flow in type 2 diabetes (T2D), human studies examining these links are limited. We provide the first measures of nitric oxide synthase and endothelin-1 expression from skeletal muscle tissue containing native microvessels in individuals with and without T2D before and during insulin stimulation. Higher basal skeletal muscle expression of endothelin-1 and reduced endothelial nitric oxide phosphorylation (peNOS)/eNOS may contribute to reduced insulin-stimulated blood flow in obese T2D patients.

Topics: Adult; Diabetes Mellitus, Type 2; Endothelin-1; Female; Femoral Artery; Glucose; Glucose Clamp Technique; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Muscle, Skeletal; Nitric Oxide Synthase; Nitric Oxide Synthase Type III; Obesity; Renal Circulation; Thinness

To assess vitreous and plasma changes of vascular endothelial growth factor A (VEGF-A), adrenomedullin (ADM) and endothelin-1 (ET-1) in proliferative diabetic retinopathy (PDR).. 9 patients with PDR in type 2 diabetes (T2DM) and 11 age-matched non-diabetic patients were enrolled. The levels of VEGF-A, ADM and ET-1 were measured using an enzyme (ELISA) and a radioimmunoassay (RIA) both in vitreous and plasma samples.. Vitreous ADM and VEGF-A levels were significantly higher in PDR patients (p=0.04 and p=0.02), whereas no differences were found in ET-1 levels (p=0.29). Plasma ADM levels were significantly higher in the PDR group (p<0.01), whereas no significant differences were found in the plasma ET-1 and VEGF-A levels (p=0.30 and p=0.37). The ADM vitreous/plasma ratio was significantly reduced in PDR group.. The role of ET-1 in advanced PDR is still controversial; it has been supposed a role limited to induce hypoxic state and promote angiogenesis in the early phases. Once the neo-angiogenic process starts, other mediators are mainly involved as VEGF and ADM. Our findings suggest that ADM is an important marker of advanced PDR as well as VEGF. Conversely, ET-1 is not significantly involved in the advanced stage of PDR.

Topics: Adrenomedullin; Adult; Aged; Aged, 80 and over; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Endothelin-1; Endothelium, Vascular; Enzyme-Linked Immunosorbent Assay; Female; Humans; Male; Middle Aged; Vascular Endothelial Growth Factor A; Vitreous Body

Microalbuminuria is a very important independent risk factor for the progression of renal diseases as well as diseases of the cardiovascular system. Pathophysiological mechanisms that lead to the development ofmicroalbuminuria in patients with diabetes are complex and they are a result of numerous factors. In the past decade, endothelin-1, the most potent vasoconstrictor peptide, was identified as animportant factor that significantly contributes to the functional and structural renal changes. The objective of this study was to investigate the relationship between plasma concentration of endothelin-1 and urinary albumin excretion in patients with type 2 diabetes mnellitus.. There were 76 patients with type 2 diabetes who were divided into those having normoalbuminuria (n-33), microalbuminuria (n=29) and macroalbuinuria (n=14), and 30 healthy controls. Plasma levels of endothelin-1 were measured by enzyme-linked immunosorbent assay.. There were significant differences in plasma concentration of endothelin-1 among groups (P<0.01). The correlation between endothelin-1. albuminuria. proteinuria and glomercular filtration rate was significant. In multiple regression analyses the plasma concentration of endothelin-l was independently and significantly associated with albuminuria (β=0.01, p=0.009), proteinuria =.02, p<0.001) and glon.erular filtration rate (P3=0βl. pO-.P=)6).0Conclu- sion. Higher plasma concentrations of endothelin-1 are independently associated with the levels of urinary, excretion of albumin Whicw May morroborate tlse hpothesis of apotenstial role of this peptide inl th de- vepment of microalbUminuriauin diabetic necphrpathy.

Topics: Adult; Aged; Albuminuria; Diabetes Mellitus, Type 2; Endothelin-1; Female; Humans; Male; Middle Aged

Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone with extrapancreatic effects beyond glycemic control. Here we demonstrate unexpected effects of GIP signaling in the vasculature. GIP induces the expression of the proatherogenic cytokine osteopontin (OPN) in mouse arteries via local release of endothelin-1 and activation of CREB. Infusion of GIP increases plasma OPN concentrations in healthy individuals. Plasma endothelin-1 and OPN concentrations are positively correlated in patients with critical limb ischemia. Fasting GIP concentrations are higher in individuals with a history of cardiovascular disease (myocardial infarction, stroke) when compared with control subjects. GIP receptor (GIPR) and OPN mRNA levels are higher in carotid endarterectomies from patients with symptoms (stroke, transient ischemic attacks, amaurosis fugax) than in asymptomatic patients, and expression associates with parameters that are characteristic of unstable and inflammatory plaques (increased lipid accumulation, macrophage infiltration, and reduced smooth muscle cell content). While GIPR expression is predominantly endothelial in healthy arteries from humans, mice, rats, and pigs, remarkable upregulation is observed in endothelial and smooth muscle cells upon culture conditions, yielding a "vascular disease-like" phenotype. Moreover, the common variant rs10423928 in the GIPR gene is associated with increased risk of stroke in patients with type 2 diabetes.

Topics: Aged; Aged, 80 and over; Animals; Aorta; Blotting, Western; Cardiovascular Diseases; Carotid Arteries; Case-Control Studies; Coronary Vessels; Cyclic AMP Response Element-Binding Protein; Diabetes Mellitus, Type 2; Endothelial Cells; Endothelin-1; Enzyme-Linked Immunosorbent Assay; Female; Fluorescent Antibody Technique; Gastric Inhibitory Polypeptide; Humans; Immunohistochemistry; Male; Mice; Mice, Knockout; Microscopy, Confocal; Microvessels; Middle Aged; Myocytes, Smooth Muscle; Osteopontin; Peripheral Arterial Disease; Plaque, Atherosclerotic; Polymorphism, Single Nucleotide; Rats; Rats, Inbred WKY; Real-Time Polymerase Chain Reaction; Receptors, Gastrointestinal Hormone; RNA, Messenger; Stroke; Sus scrofa; Swine

It is unclear whether diabetic angiopathy is related to oxidative stress-associated endothelial dysfunction. The authors investigated whether alteration of endothelin-1 and lipid peroxide production and activation of nuclear factor-κB expression were involved in lower limb amputation in type 2 diabetes mellitus patients.. A total of 135 subjects including 51 type 2 diabetes mellitus patients with major lower extremity amputations and 36 diabetes mellitus patients without limb and vascular complication and 48 normal controls were recruited for this study. The authors measured the plasma soluble endothelin-1 concentrations by a sandwich enzyme immunoassay, and measured oxidative stress as determined by the lipid peroxide byproduct malondialdehyde. Histologic staining and nuclear factor-κB activation determined by electrophoretic mobility shift assay of the amputated vessels were examined.. Histologic staining revealed that severe arteriosclerosis with atheroma formation in the amputated diabetic arteries was significantly prominent compared with normal controls. Soluble endothelin-1 concentrations and malondialdehyde levels were increased significantly in diabetic amputation patients compared with other groups (p < 0.001). The nuclear factor-κB binding activity in amputated diabetic stump vessels was more prominent compared with healthy vessels without diabetes mellitus. There was a positive correlation between endothelin-1 and malondialdehyde in patients with diabetic amputation (r = 0.46, p = 0.001).. These results suggest that elevation of endothelin-1 and lipid peroxide levels is involved in the pathogenesis of diabetic foot amputation. An increase of lipid peroxide and endothelin-1 associated with nuclear factor-κB activation plays an important role in the development of diabetic angiopathies.

Topics: Adult; Aged; Aged, 80 and over; Amputation, Surgical; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Electrophoresis; Endothelin-1; Enzyme-Linked Immunosorbent Assay; Female; Follow-Up Studies; Gene Expression Regulation; Humans; Leg; Lipid Peroxidation; Male; Middle Aged; NF-kappa B; Polymerase Chain Reaction; Retrospective Studies; RNA

We addressed whether endothelin-1, a marker of endothelial dysfunction, predicts impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM) in a population study in south-western Sweden. Follow-up after 9.7 years showed an association between circulating endothelin-1 levels at baseline and development of IGT/T2DM in women but not in men.

Topics: Biomarkers; Diabetes Mellitus, Type 2; Endothelin-1; Female; Glucose Intolerance; Glucose Tolerance Test; Humans; Longitudinal Studies; Male; Middle Aged; Sweden

Glycemic variability (GV) creates challenges to glycemic control and may be an independent marker for unfavorable outcome in management of patients with diabetes. This study was designed to investigate the effect of excessive visit-to-visit GV on the progression of endothelial and renal dysfunction in patients with type 2 diabetes mellitus (T2DM).. Two hundred and thirty nine patients with T2DM, who were recruited from outpatient, completed 48-month follow-up visit. Visit-to-visit GV was calculated by the standard deviation (SD) and coefficient of variation (CV) of serially measured HbA1c and fasting plasma glucose (FPG). Endothelial and renal function was assessed at baseline and end of follow-up.. At end of follow-up, brachial flow-mediated dilation (FMD), nitric oxide (NO), creatinine-based estimated glomeruar filtration rate (eGFR-Cr), and cystatin C-based estimated glomeruar filtration rate (eGFR-Cys C) increased, and endothelin-1 and urine albumin/creatinine ratio (ACR) declined as compared with baseline in overall (P < 0.05). The increment of FMD, NO, eGFR-Cr, and eGFR-Cys C and the decrement of endothelin-1 and ACR in first tertile group were significantly greater than those in third tertile group classified by tertile of either SD of HbA1c or SD of FPG. Change percentage of FMD, NO, eGFR-Cr, and eGFR-Cys C were positively, and change percentage of endothelin-1 and ACR were negatively correlated with SDs of HbA1c and FPG, and CVs of HbA1c FPG (P < 0.01, respectively). After adjusted for mean HbA1c, mean FPG, baseline demographic, and clinical characteristics, SD of HbA1c and SD of FPG were always statistically correlated with change percentage of FMD, NO, endothelin-1, ACR, eGFR-Cr, and eGFR-Cys C.. Excessive visit-to-visit GV independently deteriorates the progression of endothelial and renal dysfunction in patients with T2DM.

Topics: Aged; Albuminuria; Creatinine; Cystatin C; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Progression; Endothelin-1; Endothelium; Fasting; Female; Follow-Up Studies; Glomerular Filtration Rate; Glycated Hemoglobin; Humans; Kidney; Male; Middle Aged; Nitric Oxide; Office Visits; Vasodilation

Endothelin-1 (ET-1) is one of the most potent vasoconstrictors known to date. While its plasma or serum concentrations are elevated in some forms of experimental and human hypertension, this is not a consistent finding in all forms of hypertension. Matrix metalloproteinases -2 and -9 (MMP-2 and MMP-9), which degrade collagen type IV of the vascular basement membrane, are responsible for vascular remodeling, inflammation, and atherosclerotic complications, including in type 2 diabetes (T2D). In our study, we compared concentrations of ET-1, MMP-2, and MMP-9 in pre-hypertensive (PHTN) and hypertensive (HTN) T2D patients with those of healthy normotensive controls (N). ET-1, MMP-2, and MMP-9 were measured by ELISA. Concentrations of ET-1 in PHTN and N were very similar, while those in HTN were significantly higher. Concentrations of MMP-2 and MMP-9 in PHTN and HTN were also significantly higher compared to N. An interesting result in our study is that concentrations of MMP-2 and MMP-9 in HTN were lower compared to PHTN. In conclusion, we showed that increased production of ET-1 in patients with T2D can lead to long-lasting increases in blood pressure (BP) and clinical manifestation of hypertension. We also demonstrated that increased levels of MMP-2 and MMP-9 in pre-hypertensive and hypertensive patients with T2D mainly reflect the early vascular changes in extracellular matrix (ECM) turnover.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Blood Pressure; Bulgaria; Case-Control Studies; Diabetes Mellitus, Type 2; Endothelin-1; Enzyme-Linked Immunosorbent Assay; Female; Humans; Hypertension; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Middle Aged; Young Adult

Topics: Adult; Arterioles; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Endothelin-1; Female; Humans; Hyperinsulinism; Insulin; Middle Aged; Muscle, Skeletal; Nitric Oxide; Nitric Oxide Synthase Type III; Obesity; Vasoconstriction; Vasodilation

Recent studies in type 2 diabetes have reported an association between hypoglycemia and severe cardiovascular adverse events, which are relatively increased in standard versus intensively treated individuals. The aim of this study was to determine the effects of equivalent sympathetic nervous system (SNS) activity during moderate hypoglycemia on in-vivo endothelial function, pro-inflammatory, pro-atherothrombotic, and pro-coagulant responses in healthy and standard treated type 2 diabetes individuals.. Eleven type 2 diabetes and 16 healthy individuals participated in single 2day studies. Day 1 involved a 2h hyperinsulinemic/euglycemic clamp and day 2, a 2h hyperinsulinemic/hypoglycemic clamp of 3.2±1mmol/L in type 2 diabetes and (2.9±0.1mmol/L) in healthy individuals.. ICAM-1, VCAM-1, P-selectin, PAI-1, VEGF and endothelin-1 (ET-1) fell during hyperinsulinemic euglycemia but increased during hypoglycemia in type 2 diabetes and healthy individuals. Epinephrine and norepinephrine levels were equivalent during hypoglycemia in type 2 DM and healthy individuals. However, despite similar SNS drive but milder and hypoglycemia there were greater ICAM-1, VCAM-1, PAI-1, VEGF and ET-1 responses in the type 2 diabetes group. Endogenous and exogenous nitric oxide mediated arterial vasodilation were also impaired only during hypoglycemia in type 2 diabetes.. We conclude that, milder hypoglycemia but equivalent SNS activation results in more diffuse endothelial dysfunction and a greater pro-inflammatory, pro-atherothrombotic and pro-coagulant state in standard treated type 2 diabetes as compared to healthy individuals.

Topics: Adult; Atherosclerosis; Blood Coagulation; Case-Control Studies; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Female; Humans; Hypoglycemia; Hypoglycemic Agents; Inflammation; Intercellular Adhesion Molecule-1; Male; Middle Aged; Obesity; P-Selectin; Plasminogen Activator Inhibitor 1; Sympathetic Nervous System; Vascular Cell Adhesion Molecule-1; Vascular Endothelial Growth Factor A

To examine the relationships of serum markers of inflammation and endothelial function to diabetic retinopathy.. We recruited 224 patients with diabetes (85 with Type 1 and 139 with Type 2 diabetes) aged 18-70 years. Serum markers of inflammation (high-sensitivity C-reactive protein) and endothelial function (soluble intercell adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, endothelin-1 and total nitrite) were assessed using nephelometry, immunoassays and spectroscopy. Diabetic retinopathy was graded from two-field fundus photographs according to the Airlie House Classification system and was categorized into no diabetic retinopathy, mild non-proliferative diabetic retinopathy, moderate non-proliferative diabetic retinopathy and vision-threatening diabetic retinopathy, the latter comprising severe non-proliferative diabetic retinopathy, proliferative diabetic retinopathy or clinically significant macular oedema. Multinomial logistic regression was used to assess the associations between serum markers and diabetic retinopathy.. In the study, 64% of patients (144/224) had diabetic retinopathy and 25% (57/244) had vision-threatening diabetic retinopathy. After controlling for age, gender, diabetes duration, HbA1c , systolic blood pressure, total and HDL cholesterol, smoking, the use of insulin or oral hypoglycaemic agents, nephropathy and cardiovascular disease, a positive association was found between increasing high-sensitivity C-reactive protein levels and the presence of vision-threatening diabetic retinopathy (odds ratio 1.26; 95% CI 1.05-1.51, per sd increase in high-sensitivity C-reactive protein). After stratifying by BMI ( ≥ 30 and < 30 kg/m(2) ), this association was found to be more pronounced in people with a BMI ≥ 30 kg/m(2) (odds ratio 2.9; P for interaction = 0.019). No associations were found between serum markers of endothelial activation and diabetic retinopathy.. Higher C-reactive protein levels, but not markers of endothelial function, may be related to more severe diabetic retinopathy. This finding suggests that inflammatory processes are involved in severe diabetic retinopathy, particularly in patients with a BMI ≥ 30 kg/m(2) .

Topics: Adolescent; Adult; Aged; Biomarkers; C-Reactive Protein; Cross-Sectional Studies; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Retinopathy; E-Selectin; Endothelin-1; Endothelium, Vascular; Female; Humans; Inflammation; Intercellular Adhesion Molecule-1; Logistic Models; Male; Middle Aged; Nitrates; Ophthalmoscopes; Severity of Illness Index; Vascular Cell Adhesion Molecule-1; Young Adult

Vascular risk factors are associated with a higher incidence of dementia. In fact, diabetes mellitus is considered a main risk factor for Alzheimer's disease (AD) and both diseases are characterized by vascular dysfunction. However, the underlying mechanisms remain largely unknown. Here, the effects of high-sucrose-induced type 2 diabetes (T2D) in the aorta of wild type (WT) and triple-transgenic AD (3xTg-AD) mice were investigated. 3xTg-AD mice showed a significant decrease in body weight and an increase in postprandial glycemia, glycated hemoglobin (HbA1c), and vascular nitrotyrosine, superoxide anion (O2•-), receptor for the advanced glycation end products (RAGE) protein, and monocyte chemoattractant protein-1 (MCP-1) levels when compared to WT mice. High-sucrose intake caused a significant increase in body weight, postprandial glycemia, HbA1c, triglycerides, plasma vascular cell adhesion molecule 1 (VCAM-1), and vascular nitrotyrosine, O2•-, RAGE, and MCP-1 levels in both WT and 3xTg-AD mice when compared to the respective control group. Also, a significant decrease in nitric oxide-dependent vasorelaxation was observed in 3xTg-AD and sucrose-treated WT mice. In conclusion, AD and T2D promote similar vascular dysfunction of the aorta, this effect being associated with elevated oxidative and nitrosative stress and inflammation. Also, AD-associated vascular alterations are potentiated by T2D. These findings support the idea that metabolic alterations predispose to the onset and progression of dementia.

Topics: Acetylcholine; Alzheimer Disease; Amyloid beta-Protein Precursor; Analysis of Variance; Animals; Aorta; Diabetes Mellitus, Type 2; Disease Models, Animal; Endothelin-1; Humans; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mutation; Nitroprusside; Presenilin-1; Superoxide Dismutase; tau Proteins; Vasodilator Agents

Type 2 diabetes (DMT2) combined with ischemic heart disease (IHD) promotes the occurrence and development of coronary atherosclerosis. We aimed to provide a theoretical basis for improving patient prognosis through analyzing expression of plasma brain natriuretic peptide (BNP), endothelin-1 (ET 1), and matrix metalloproteinase 9 (MMP-9).. Enzyme-linked immunosorbent assay (ELISA) was used to detect BNP, ET-1, and MMP-9 levels in 50 patients with DMT2 only (group A), 47 patients with IHD only (group B), 43 patients with comorbid (both) IHD and DMT2 (group C), and 50 health controls (group D). Group C was further divided into single-branch lesion group, double-branch lesions group, and triple-branch lesion group according to coronary angiography, or cardiac function grade II, III, and IV group according to cardiac function, and their BNP, ET-1, and MMP-9 levels were compared.. Compared with group D, TG, diastolic, and systolic blood pressure were all significantly elevated in groups A, B, and C. Group C exhibited obviously higher glycosylated hemoglobin than group A. Gensini score in group C was markedly higher than in group B. Compared with group D, BNP, ET-1, and MMP-9 levels were all increased in groups A, B, and C. Group C showed higher levels of BNP, ET-1, and MMP-9 than group A and B. BNP, ET-1, and MMP-9 levels in the triple-branch lesions group were higher than in the single-branch lesions group and double-branch lesions group. The cardiac function grade IV group presented higher levels of BNP, ET-1, and MMP-9 than did the grade II and III groups. BNP, ET-1, and MMP-9 showed a positive correlation to each other.. BNP, ET-1, and MMP-9 may participate in the occurrence and development of comorbid DMT2 and IHD. They are important objective indicators for evaluating severity and prognosis of patients with comorbid DMA2 and IHD.

Topics: Adult; Aged; Biomarkers; Coronary Artery Disease; Diabetes Mellitus, Type 2; Endothelin-1; Enzyme-Linked Immunosorbent Assay; Female; Heart Function Tests; Humans; Male; Matrix Metalloproteinase 9; Middle Aged; Myocardial Ischemia; Natriuretic Peptide, Brain; Prognosis

Diabetic peripheral neuropathy (DPN) is one of the most common diabetic chronic complications. There is an increased attention directed towards the role of angiogenic factors including vascular endothelial growth factor (VEGF) and anti-angiogenic factors including soluble endoglin (sEng) as contributors to diabetic microvascular complications including neuropathy. The purposes of this study were to determine the role of these angiogenesis regulators in the prognosis of DPN. The study group included 60 patients with type 2 diabetes mellitus (T2DM) and 20 clinically healthy individuals. The patients were divided into two groups. Group I included 20 T2DM patients without peripheral neuropathy, and Group II consisted of 40 T2DM patients with DPN. In all groups, plasma VEGF, sEng and endothelin-1 (ET-1), nitric oxide and ET-1 mRNA were estimated. Plasma levels of VEGF, sEng, ET-1 and nitric oxide were significantly elevated in diabetic patients (Groups I and II) compared with healthy control subjects, with a higher increase in their levels in patients with DPN compared with diabetic patients without peripheral neuropathy. Measurement of plasma levels of angiogenesis-related biomarkers in high-risk diabetic patients might identify who later develop DPN, thus providing opportunities for early detection and targets for novel treatments.

Topics: Adult; Aged; Antigens, CD; Biomarkers; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Neuropathies; Endoglin; Endothelin-1; Female; Humans; Male; Middle Aged; Neovascularization, Physiologic; Nitric Oxide; Receptors, Cell Surface; RNA, Messenger; Vascular Endothelial Growth Factor A

The purpose of this study was to determine endothelin (ET)-1 and nitric oxide (NO) serum concentration levels at baseline and after 1 year of peritoneal dialysis (PD) treatment. A further aim was to evaluate the association between ET-1 and NO with parameters of echocardiography and the common carotid artery (CCA) ultrasound, and to assess their impact on cardiovascular remodeling. We also aimed to evaluate the influence of dialysis adequacy and residual renal function (RRF) on cardiovascular remodeling.. This study included 40 PD patients in whom we measured serum ET-1 and NO concentrations, echocardiography and CCA ultrasound parameters.. ET-1 decreased and NO serum concentration levels increased (p < 0.01) after 12 months of PD treatment compared to baseline values. Left ventricular (LV) hypertrophy was observed in 77.5% of patients at baseline with significant reduction in LV mass index (LVMI), CCA intima media thickness (IMT) and plaque score after 12 months of PD treatment (p < 0.001). The dialysis adequacy and RRF were significantly associated with LVMI and CCA IMT after 12 months on PD.. In our study, ET-1 significantly decreased while NO increased during PD treatment and both were independently related to the cardiovascular remodeling parameters in PD patients.

Topics: Adult; Aged; Biomarkers; Carotid Artery Diseases; Diabetes Mellitus, Type 2; Endothelin-1; Female; Follow-Up Studies; Humans; Hypertrophy, Left Ventricular; Kidney Failure, Chronic; Male; Middle Aged; Nitric Oxide; Peritoneal Dialysis; Prospective Studies; Ultrasonography; Ventricular Remodeling

To study the relationship between plasma soluble klotho (sKlotho) and pro-endothelin-1 (proET-1) in patients with type 2 diabetes (T2DM).. In this cross-sectional study, we recruited 175 T2DM subjects and 56 non-diabetic controls. Plasma sKlotho, proET-1 and extracellular superoxide dismutase (SOD) were measured by ELISA and ILMA, respectively.. Plasma sKlotho level in patients with T2DM was lower compared to that in non-diabetic controls (416.8±148.1 vs. 494.6±134.3 pg/ml, p=0.001) and showed significant interaction with diabetes status in its association with proET-1. Plasma sKlotho was inversely correlated with proET-1 in T2DM (Rho=-0.410, p<0.0001) but not in non-diabetic controls (Rho=0.091, p=0.505). Multivariable linear regression models revealed that sKlotho was independently associated with proET-1 after adjustment for renal filtration function, albuminuria, diabetes duration, HbA1c, systolic and diastolic blood pressure.. Plasma sKlotho was associated with proET-1 independent of renal function in patients with T2DM.

Topics: Aged; Albuminuria; Blood Glucose; Blood Pressure; Body Mass Index; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Nephropathies; Diabetic Neuropathies; Endothelin-1; Female; Glomerular Filtration Rate; Glucuronidase; Glycated Hemoglobin; Humans; Klotho Proteins; Lipids; Male; Middle Aged; Oxidative Stress; Protein Precursors; Superoxide Dismutase

Epidemiological and clinical studies have reported that olive oil reduces the incidence of cardiovascular disease. However, the mechanisms involved in this beneficial effect have not been delineated. The endothelium plays an important role in blood pressure regulation through the release of potent vasodilator and vasoconstrictor agents such as nitric oxide (NO) and endothelin-1 (ET-1), respectively, events that are disrupted in type 2 diabetes. Extra virgin olive oil contains polyphenols, compounds that exert a biological action on endothelial function. This study analyzes the effects of olive oil polyphenols on endothelial dysfunction using an in vitro model that simulates the conditions of type 2 diabetes. Our findings show that high glucose and linoleic and oleic acids decrease endothelial NO synthase phosphorylation, and consequently intracellular NO levels, and increase ET-1 synthesis by ECV304 cells. These effects may be related to the stimulation of reactive oxygen species production in these experimental conditions. Hydroxytyrosol and the polyphenol extract from extra virgin olive oil partially reversed the above events. Moreover, we observed that high glucose and free fatty acids reduced NO and increased ET-1 levels induced by acetylcholine through the modulation of intracellular calcium concentrations and endothelial NO synthase phosphorylation, events also reverted by hydroxytyrosol and polyphenol extract. Thus, our results suggest a protective effect of olive oil polyphenols on endothelial dysfunction induced by hyperglycemia and free fatty acids.

Topics: Cell Line; Diabetes Mellitus, Type 2; Endothelial Cells; Endothelin-1; Fatty Acids, Nonesterified; Glucose; Linoleic Acid; Nitric Oxide; Nitric Oxide Synthase Type III; Oleic Acid; Olive Oil; Polyphenols

Cardiac function is adversely affected by pericardial adiposity. We investigated the effects of the heme oxygenase (HO) inducer, hemin on pericardial adiposity, macrophage polarization, and diabetic cardiopathy in Zucker diabetic fatty rats (ZDFs) with use of echocardiographic, quantitative real-time polymerase chain reaction, Western immunoblotting, enzyme immunoassay, and spectrophotometric analysis. In ZDFs, hemin administration increased HO activity; normalized glycemia; potentiated insulin signaling by enhancing insulin receptor substrate 1(IRS-1), phosphatidylinositol-3-kinase (PI3K), and protein kinase B (PKB)/Akt; suppressed pericardial adiposity, cardiac hypertrophy, and left ventricular longitudinal muscle fiber thickness, a pathophysiological feature of cardiomyocyte hypertrophy; and correspondingly reduced systolic blood pressure, total peripheral resistance, and pro-inflammatory/oxidative mediators, including nuclear factor κB (NF-κB), cJNK, c-Jun-N-terminal kinase (cJNK), endothelin (ET-1), tumor necrosis factor α (TNF-α), interleukin (IL)-6, IL-1β, activating protein 1 (AP-1), and 8-isoprostane, whereas the HO inhibitor, stannous mesoporphyrin, nullified the effects. Furthermore, hemin reduced the pro-inflammatory macrophage M1 phenotype, but enhanced the M2 phenotype that dampens inflammation. Because NF-κB activates TNFα, IL-6, and IL-1β and TNF-α, cJNK, and AP-1 impair insulin signaling, the high levels of these cytokines in obesity/diabetes would create a vicious cycle that, together with 8-isoprostane and ET-1, exacerbates cardiac injury, compromising cardiac function. Therefore, the concomitant reduction of pro-inflammatory cytokines and macrophage infiltration coupled to increased expressions of IRS-1, PI3K, and PKB may account for enhanced glucose metabolism and amelioration of cardiac injury and function in diabetic cardiomyopathy. The hemin-induced preferential polarization of macrophages toward anti-inflammatory macrophage M2 phenotype in cardiac tissue with concomitant suppression of pericardial adiposity in ZDFs are novel findings. These data unveil the benefits of hemin against pericardial adiposity, impaired insulin signaling, and diabetic cardiomyopathy and suggest that its multifaceted protective mechanisms include the suppression of inflammatory/oxidative mediators.

Topics: Adiposity; Algorithms; Animals; Blood Glucose; Blotting, Western; Coronary Circulation; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Cardiomyopathies; Endothelin-1; Heme Oxygenase (Decyclizing); Hemin; Insulin Resistance; Isoprostanes; Macrophages; Male; Myocytes, Cardiac; Phenotype; Rats; Rats, Zucker; Transcription Factor RelA; Ultrasonography; Ventricular Function, Left

Propofol has been reported to have an inhibitory effect on ischemia/reperfusion (I/R) injury in various experimental models by reducing oxidative stress, protecting mitochondrial function and suppressing apoptosis. The aim of this study was to investigate the effect and mechanism of propofol on myocardial I/R injury in type 2 diabetic rats.. A total of 24 streptozotocin (STZ)-induced diabetic rats were randomly divided into three equal groups as follows: the DI group with myocardial I/R, which was induced by occluding the left anterior descending coronary artery for 30min, followed by 2h of reperfusion; the DP group, which underwent I/R and propofol infusion at 6mg·kg(-1)·h(-1); and the DC group, which underwent sham operations without tightening of the coronary sutures. As a control, 24 healthy, age-matched, male Wistar rats were randomly divided into three equal groups: the CI, CP and CC groups. The injured cardiac tissues were removed for microscopic examination after reperfusion. The serum concentrations of nitric oxide (NO) and endothelin (ET-1); the expression of Bax, Bcl-2 and Caspase-3 within the cardiac structures; and the number of apoptotic myocardial cells were measured.. Compared with the baseline levels before ischemia, the serum concentration of ET-1 after 2h of reperfusion was increased in the CI and DI groups, while the concentration of NO in these groups decreased after reperfusion. Compared with the I/R groups, propofol increased the content of NO and decreased the content of ET-1. Compared with the sham operation groups, I/R decreased the ratio of the anti-apoptotic protein Bcl-2 to the pro-apoptotic protein Bax, which resulted in an elevation of the index of apoptosis (AI). In contrast, compared with the I/R group, propofol increased the Bcl-2-to-Bax ratio and decreased the AI. I/R increased the expression of caspase-3 compared with the sham treatment groups, while treatment with propofol reduced caspase-3 expression relative to the I/R groups.. These data suggest that propofol can protect against myocardial ischemia-reperfusion injury in both normal and type 2 diabetic rats, possibly by attenuating endothelial cell injury and inhibiting the apoptosis of cardiomyocytes.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Cytoprotection; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Endothelial Cells; Endothelin-1; Male; Myocardial Reperfusion Injury; Myocytes, Cardiac; Nitric Oxide; Propofol; Protective Agents; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Wistar

The study was designed to test the effect of anti-diabetic agent pioglitazone and Endothelin-1 (ET-1) on adiponectin secretion from human adipose tissue in depot dependent manner.. Subcutaneous adipose tissue (SAT) and omental adipose tissues (OAT) were obtained from 19 subjects, including 6 non-obese controls, 7 obese and 6 obese T2DM patients. Adipose tissue was treated with pioglitazone and ET1. Adiponectin secreted into the culture medium after treatment at different time interval (0, 24, 48, 96 hours) was determined by ELISA and normalized for cellular DNA content.. Basal adiponectin secretion from both the depots significantly associated with serum adiponectin, BMI, waist and HOMA-IR. Though no depot-specific difference was found in adiponectin secretion from SAT and OAT in our population, significant reduction in adiponectin secretion was observed in SAT of obese and T2DM patients compared to controls. Responsiveness to pioglitazone treatment was more in SAT, while ET1 inhibits adiponectin secretion in OAT.. These data suggest that, SAT, appears to be major contributor to regulation of adiponectin in circulation. Pioglitazone stimulate adiponectin secretion in SAT compared to OAT in diabetic patients while ET-1 inhibiting adiponectin secretion in OAT of diabetic patients. We need to focus on mechanism underlying these regulatory agents mediated stimulation or inhibition of adiponectin secretion in human adipose tissue.

Topics: Adiponectin; Adult; Aged; Diabetes Mellitus, Type 2; Endothelin-1; Female; Humans; Hypoglycemic Agents; Intra-Abdominal Fat; Male; Middle Aged; Obesity; Omentum; Pilot Projects; Pioglitazone; Subcutaneous Fat, Abdominal; Thiazolidinediones; Tissue Culture Techniques

To observe the influence of high blood glucose fluctuation on the endothelial function of type 2 diabetes mellitus (T2DM) rats and the effects of Panax Quinquefolius Saponin (PQS) of stem and leaf.. The T2DM model was induced by intraperitoneal injection of a small dose of streptozotocin (STZ, 35 mg/kg) plus high fat and high caloric laboratory chow. Then, diabetic rats were divided into steady high blood glucose (SHG) group and fluctuant high blood glucose (FHG) group according to fasting blood glucose coefficient of variation (FBG-CV), and then, the FHG group rats were divided into 4 groups according to the level of FBG-CV and fasting blood glucose: PQS 30 mg/(kg·d) group, PQS 60 mg/(kg·d) group, metformin hydrochloride control (MHC) group, and FHG control group, 10 in each group. Meanwhile, 10 rats without any treatment were used as normal control (NOR) group. Eight weeks later, the aortic arteries histology, plasma hepatocyte growth factor (HGF), and serum nitric oxide (NO), endothelin-1 (ET-1), tumor necrosis factor α (TNF-α), and soluble intercellular adhesion molecule 1 (sICAM-1) were measured.. In comparison with the NOR group, the level of plasma HGF and serum NO, ET-1 and TNF-α, and sICAM-1 in SHG and FHG control groups were all significantly increased (P<0.01); in comparison with the SHG group, plasma HGF and serum NO, ET-1, TNF-α, and sICAM-1 in FHG group were all significantly increased further (P<0.01 or P<0.05); meanwhile, in comparison with the FHG control group, the level of plasma HGF and serum NO, ET-1, TNF-α, and sICAM-1 in PQS and MHC groups were all decreased significantly (P<0.01). However, comparison of the aortic arteries histology among groups showed no significant differences either before or after treatment.. Blood glucose fluctuation could facilitate the development of vascular endothelial dysfunction in T2DM rats, while PQS could improve the endothelial function of T2DM rats with high blood glucose fluctuation, which may be related to its effects of relieving vessel stress, decreasing vasoconstrictor ET-1 production, preventing compensated increase of NO, and reducing inflammatory reaction.

Topics: Animals; Aorta; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Hepatocyte Growth Factor; Intercellular Adhesion Molecule-1; Male; Nitric Oxide; Panax; Plant Leaves; Plant Stems; Rats; Saponins; Solubility; Tumor Necrosis Factor-alpha

Coronary heart disease is a major cause of mortality in women and persons with diabetes. Mental stress and major depressive disorder have both been associated with coronary heart disease. Endothelial functioning is a clinically meaningful manifestation of CHD that is detectable in its earliest stages.. This study aims to determine whether acute stress and lifetime history of major depressive disorder are associated with functional and biochemical markers of endothelial function and whether this relationship varies by diabetes status.. Resting endothelial function was assessed for n = 215 postmenopausal women with no known or suspected coronary artery disease participated. Of these, 108 had a positive lifetime major depressive disorder (L-MDD; assessed through structured clinical interview) and had been free of major depressive disorder for >6 months; 103 had type 2 diabetes. Endothelial reactivity to acute mental stress was assessed for n = 114 of the participants. Endothelial function was assessed by flow-mediated dilation of the brachial artery (FMD) by total plasma nitrite, the cumulative molecule from nitric oxide (NO) generation, and by plasma endothelin-1 (ET-1).. Participants with L-MDD had lower NO and lower FMD compared to never-depressed controls. Secondary analyses suggest that among participants with L-MDD, antidepressant medications are associated with higher NO. Participants with diabetes had higher NO but lower FMD than nondiabetic controls. Mental stress affected FMD in the entire sample. Diabetes moderated the effect of mental stress on NO and L-MDD moderated the effect of mental stress on ET-1.. History of depression, even in full remission, is associated with impaired endothelial functioning regardless of diabetes status. Acute mental alters FMD, NO, and ET-1 differentially among subgroups.

Topics: Aged; Brachial Artery; Coronary Disease; Depressive Disorder, Major; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Female; Humans; Middle Aged; Postmenopause; Stress, Psychological

Circulating levels of endothelin (ET)-1 are increased in the diabetic state, as is endogenous ET(A)-receptor-mediated vasoconstriction. However, the responsible mechanisms remain unknown. We hypothesized that ET-1-induced vasoconstriction is augmented in type 2 diabetes with hyperglycemia through an increment in advanced glycation end-products (AGEs). So, we investigated whether treatment with aminoguanidine (AG), an inhibitor of AGEs, would normalize the ET-1-induced contraction induced by ET-1 in strips of thoracic aortas isolated from OLETF rats at the chronic stage of diabetes. In such aortas (vs. those from age-matched genetic control LETO rats): (1) the ET-1-induced contraction was enhanced, (2) the levels of HIF1α/ECE1/plasma ET-1 and plasma CML-AGEs were increased, (3) the ET-1-stimulated ERK phosphorylation mediated by ET(A)-R was increased, (4) the expression level of Jab1-modified ET(A)-R protein was reduced, and (5) the expression level of O-GlcNAcylated ET(A)-R protein was increased. Aortas isolated from such OLETF rats that had been treated with AG (50mg/kg/day for 10 weeks) exhibited reduced ET-1-induced contraction, suppressed ET-1-stimulated ERK phosphorylation accompanied by down-regulation of ET(A)-R, and increased modification of ET(A)-R by Jab1. Such AG-treated rats exhibited normalized plasma ET-1 and CML-AGE levels, and their aortas exhibited decreased HIF1α/ECE1 expression. However, such AG treatment did not alter the elevated levels of plasma glucose or insulin, or systolic blood pressure seen in OLETF rats. These data from the OLETF model suggest that within the timescale studied here, AG normalizes ET-1-induced aortic contraction by suppressing ET(A)-R/ERK activities and/or by normalizing the imbalance between Jab1 and O-GlcNAc in type 2 diabetes.

Topics: Acetylglucosamine; Animals; Aorta, Thoracic; Blood Glucose; Blood Pressure; COP9 Signalosome Complex; Diabetes Mellitus, Type 2; Dinoprostone; Endothelin-1; Endothelins; Extracellular Signal-Regulated MAP Kinases; Glycation End Products, Advanced; Guanidines; In Vitro Techniques; Insulin; Intracellular Signaling Peptides and Proteins; Male; Peptide Fragments; Phenylephrine; Phosphorylation; Proteins; Rats; Rats, Inbred OLETF; Receptor, Endothelin A; Receptor, Endothelin B; Vasoconstriction

We sought to identify novel urinary biomarkers of kidney function in type 2 diabetes. We screened the renal transcriptome of db/db and db/m mice for differentially expressed mRNA transcripts that encode secreted proteins with human orthologs. Whether elevated urine levels of the orthologous proteins correlated with diminished glomerular filtration rate was tested in a cross-sectional study of n = 56 patients with type 2 diabetes. We identified 36 putative biomarker genes in db/db kidneys: 31 upregulated and 5 downregulated. Urinary protein levels of six selected candidates (endothelin-1, lipocalin-2, transforming growth factor-β, growth and differentiation factor-15, interleukin-6, and macrophage chemoattractant protein-1) were elevated in type 2 diabetic patients with subnormal glomerular filtration rate (i.e., <90 ml·min(-1)·1.73 m(-2)), independent of microalbuminuria, age, sex, race, and use of angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists. In contrast, urinary levels of fibroblast growth factor were not increased. A composite variable of urine albumin and any of the six candidate markers was associated with subnormal estimated glomerular filtration rate more closely than albumin alone. In addition, urinary endothelin-1, growth and differentiation factor-15, and interleukin-6 were associated with a marker of proximal tubule damage, N-acetyl-β-d-glucosaminidase activity. These results suggest that gene expression profiling in diabetic mouse kidney can complement existing proteomic-based approaches for renal biomarker discovery in humans.

Topics: Acute-Phase Proteins; Adult; Animals; Biomarkers; Case-Control Studies; Chemokine CCL2; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelin-1; Female; Glomerular Filtration Rate; Growth Differentiation Factor 15; Humans; Immunoassay; Interleukin-6; Kidney; Lipocalin-2; Lipocalins; Male; Mice; Middle Aged; Pilot Projects; Proto-Oncogene Proteins; Transcriptome; Transforming Growth Factor beta

Diabetes is known to cause alteration of the endothelin (ET) system. We have previously demonstrated that ETs regulate augmented production of extracellular matrix proteins causing structural alterations in type 1 diabetes. Here we investigated the effects of macitentan, an orally-active, tissue-targeting dual ET receptor antagonist on chronic complications in type 2 diabetes.. db/db mice and their age- and sex-matched controls were examined after 2 and 4 months of diabetes. Groups of diabetic animals were treated with oral macitentan (25mg/kg/day). The animals were monitored with respect to body weight and blood glucose. Urine analyses were performed for albumin. Cardiac hemodynamic studies were carried out. Renal, cardiac and retinal tissues were analyzed for ET-1, transforming growth factor-β1 (TGF-β1), vascular endothelial growth factor (VEGF), fibronectin (FN), extradomain B containing FN (EDB(+)FN) and collagen α-I (IV) mRNA. Cardiac atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were measured. Protein expressions were measured by ELISA and Western blot. Microscopic analyses were performed in the kidneys.. Diabetic animals showed hyperglycemia, increased urinary albumin and augmented serum creatinine levels. Diabetes caused increased renal, cardiac and retinal ET-1, TGF-β1, VEGF, FN, EDB(+)FN, collagen α-I(IV) mRNA expression along with increased FN and collagen protein and NF-κB activation. Diabetic mice also demonstrated mesangial expansion, cardiac dysfunction and increased expression of ANP and BNP. Treatment with macitentan attenuated such abnormalities.. These experiments confirmed that ET system plays a significant role in the pathogenesis of chronic complications in type 2 diabetes. Such diabetes induced changes can be reduced macitentan therapy.

Topics: Animals; Blotting, Western; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Endothelin A Receptor Antagonists; Endothelin B Receptor Antagonists; Endothelin-1; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation; Kidney; Male; Mice; Myocardium; Pyrimidines; Retina; Sulfonamides; Time Factors

Protective effects of two different extracts of TSCA (total saponins from Cicer arietinum) were studied on kidney of T2DM rats. The diabetic model group was established with high calorie feeding and small dose injection of streptozotocin (STZ, 45 mg x kg(-1)). DM rats were randomly assigned to model group (feed with propylene glycol 1 mL/100 g), TSCA high dose group (300 mg x kg(-1)), TSCA low dose group (100 mg x kg(-1)) and normal control group (feed with propylene glycol 1 mL/100 g). After four weeks treatment with TSCA I and II, the levels of FPG FIns, BUN, Scr, ATII, ET-1, TXB2 and 6-keto-PGF1alpha in blood and the activities of SOD, GSH-PX and MDA in kidney were analyzed by biochemical methods. After four weeks treatment with TSCA II, the levels of FPG FIns, BUN, Scr, ATII and ET-1 were reduced significantly; and the ratios of TXB2 to 6-keto-PGF1alpha and SOD were effectively alleviated in TSCA II group. While there is no significant change on FPG and BUN in comparison to the rats treated with TSCA I, Scr, ATII, ET-I, GSH-PX and SOD were alleviated. The results suggest that TSCA II could be used to reduce FPG and FIns. According to the result of vasoactive substances index, TSCA II is more effective than TSCA I on renal protection of DM rats.

Topics: 6-Ketoprostaglandin F1 alpha; Angiotensin II; Animals; Blood Glucose; Blood Urea Nitrogen; Cicer; Creatinine; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Endothelin-1; Glutathione Peroxidase; Hypoglycemic Agents; Insulin; Kidney; Male; Malondialdehyde; Plants, Medicinal; Random Allocation; Rats; Rats, Wistar; Saponins; Superoxide Dismutase; Thromboxane B2

The aim of this study was to investigate the association between plasma COOH-terminal proendothelin-1 (CT-proET-1) and fatal cardiovascular events, all-cause mortality, and new-onset albuminuria in patients with type 2 diabetes.. A total of 1,225 patients with type 2 diabetes participated in this prospective observational study of two combined cohorts. Three clinical end points were studied: fatal cardiovascular events, all-cause mortality, and new-onset albuminuria. After a median follow-up of 3 or 10 years, Cox proportional hazard modeling was used to investigate the association between CT-proET-1 and the end points. Harrell C statistic, the Groennesby and Borgan test, the integrated discrimination improvement (IDI), and the net reclassification improvement (NRI) were used to evaluate whether CT-proET-1 is of additional value compared with classic cardiovascular and renal risk factors.. During follow-up, 364 (30%) patients died, 150 (42%) of whom died of cardiovascular disease; 182 (26.7%) of 688 patients with normoalbuminuria at baseline developed albuminuria. CT-proET-1 was associated with fatal cardiovascular events, all-cause mortality, and new-onset albuminuria with hazard ratios of 1.59 (95% CI 1.15-2.20), 1.41 (95% CI 1.14-1.74), and 1.48 (95% CI 1.10-2.01), respectively. Addition of CT-proET-1 to a model containing traditional risk factors leads only to improved prediction of fatal cardiovascular events. The IDI appeared significant for fatal cardiovascular events (0.82 [0.1-1.54]) and all-cause mortality (0.4 [0.05-0.92]), but not for new-onset albuminuria.. CT-proET-1 has additional value for the prediction of fatal cardiovascular events and new-onset albuminuria in patients with type 2 diabetes, compared with conventional risk factors, but not for all-cause mortality.

Topics: Adult; Albuminuria; Biomarkers; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Endothelin-1; Female; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Peptide Fragments; Prospective Studies; Young Adult

Endothelin (ET)-1 is a likely candidate for a key role in diabetic vascular complications. In the present study, we hypothesized that treatment with pravastatin (an inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase) would normalize the ET-1-induced contraction in aortas isolated from type 2 diabetic Otsuka Long-Evans Tokushima fatty (OLETF) rats. Contractile responses were examined by measuring isometric force in endothelium-denuded aortic helical strips from four groups: Long-Evans Tokushima Otsuka (LETO; genetic control), OLETF (type 2 diabetic), pravastatin-treated LETO, and pravastatin-treated OLETF rats. Both immunoblot analysis and immunoprecipitation assays were used to examine Src, protein phosphatase (PP)2A, kinase suppressor of Ras (KSR)1, and ERK signaling pathway protein levels and activities. In endothelium-denuded aortas isolated from OLETF rats at the chronic stage of diabetes (56-60 wk) (vs. those from age-matched LETO rats), we found the following: 1) ET-1-induced contraction was enhanced, 2) ERK1/2 phosphorylation was increased, 3) phosphorylations of KSR1 and PP2A were reduced (i.e., enhancement of the kinase active state), 4) ERK1/2-KSR1 complexes were increased, and 5) Src tyrosine kinase activity was diminished. Endothelium-denuded aortas isolated from OLETF rats treated with pravastatin (10 mg/kg po, daily for 4 wk) exhibited normalized ET-1-induced contractions and suppressed ET-1-stimulated ERK phosphorylation, with the associated phosphorylated KSR1 and phosphorylated PP2A levels being increased toward normal levels. These results suggest that in type 2 diabetic rats, pravastatin normalizes ET-1-induced contraction in aortic smooth muscle via a suppression of PP2A/KSR1/ERK activities after an enhancement of Src kinase activity.

Topics: Animals; Aorta, Thoracic; Aortic Diseases; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelin-1; Enzyme Activation; Extracellular Signal-Regulated MAP Kinases; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Phosphorylation; Pravastatin; Protein Kinases; Protein Phosphatase 2; Rats; Rats, Inbred OLETF; Signal Transduction; src-Family Kinases; Time Factors; Vasoconstriction; Vasoconstrictor Agents

Prevention and treatment of type 2 diabetes includes recommendation to perform aerobic exercise, but evidence indicates that high-intensity exercise training may confer greater benefit. Unique motor recruitment patterns during exercise elicit spatially focused increases in blood flow and subsequent adaptations. Therefore, using 20-wk-old Otsuka Long Evans Tokushima fatty (OLETF) rats with advanced insulin resistance, we examined whether 12 wk of exercise protocols that elicit different motor unit recruitment patterns, endurance exercise (EndEx), and interval sprint training (IST) induce spatially differential effects on endothelial-dependent dilation to acetylcholine (ACh; 1 nM-100 μM) and vasoreactivity to insulin (1-1,000 μIU/ml) in isolated, pressurized skeletal muscle resistance arterioles. Compared with sedentary OLETF rats, EndEx enhanced sensitivity to ACh in second-order arterioles perfusing the "red" (G2A-R) and "white" (G2A-W) portions of the gastrocnemius (EC(50): +36.0 and +31.7%, respectively), whereas IST only increased sensitivity to ACh in the G2A-R (+35.5%). Significant heterogeneity in the vasomotor response to insulin was observed between EndEx and IST as mean endothelin-1 contribution in EndEx was 27.3 ± 7.6 and 25.9 ± 11.0% lower in the G2A-R and G2A-W, respectively. These microvascular effects of exercise were observed in conjunction with training-related improvements in glycemic control (HbA1c: 6.84 ± 0.23, 5.39 ± 0.06, and 5.30 ± 0.14% in sedentary, EndEx, and IST, respectively). In summary, this study provides novel evidence that treatment of advanced insulin resistance in the OLETF rat with exercise paradigms that elicit diverse motor recruitment patterns produce differential adaptive responses in endothelial-dependent dilation and in the complex vascular actions of insulin.

Topics: Acetylcholine; Animals; Arterioles; Diabetes Mellitus, Type 2; Endothelin-1; Insulin; Insulin Resistance; Male; Microvessels; Muscle, Skeletal; Physical Conditioning, Animal; Physical Endurance; Rats; Rats, Inbred OLETF; Vasodilation; Vasomotor System

Diabetes mellitus is the leading cause of vascular complications such as atherosclerosis. This study was designed to investigate whether Prunella vulgaris (APV) would inhibit diabetic atherosclerosis in db/db mice with type 2 diabetes. The db/db mice were treated with high fat/high cholesterol (HFHC) diet and an aqueous extract of APV (100 and 200 mg/kg/day) for eight weeks to examine the long-term effect on metabolic abnormalities and diabetic atherosclerosis. APV treatment markedly lowered blood glucose and systolic blood pressure. The db/db mice experienced an increase in blood urea nitrogen as well as a decrease of creatinine clearance, the latter of which was restored by treatment with APV. Treatment with APV markedly decreased total plasma cholesterol, triglyceride, and LDL-cholesterol and also increased the HDL-cholesterol. In addition, malondialdehyde and TGF-β1 were decreased by treatment of APV. On the other hand, total NO level was decreased in db/db mice. However, the NO level was increased by treatment with APV, suggesting an association with vascular dysfunction. Vascular relaxation of aortic rings by acetylcholine or SNP-inducement was ameliorated by APV in a dose-dependent manner. Damage of vascular intima and hypertrophic of media were observed in db/db mice; however its dysfunction was improved by the treatment of APV. APV treatment significantly reduced the aortic expressions of ICAM-1, VCAM-1, ET-1, and nitrotyrosine. Furthermore, expression of eNOS in aortic was remarkably increased by APV treatment. Taken together, APV suppressed hyperglycemia and diabetic vascular dysfunction in HFHC diet-db/db mice. The present data suggest that Prunella vulgaris may prevent development of diabetic atherosclerosis.

Topics: Acetylcholine; Animals; Aorta; Atherosclerosis; Blood Glucose; Blood Pressure; Blood Urea Nitrogen; Cholesterol, Dietary; Creatinine; Diabetes Complications; Diabetes Mellitus, Type 2; Diet, High-Fat; Dose-Response Relationship, Drug; Endothelin-1; Hyperglycemia; Hypertrophy; Hypoglycemic Agents; Intercellular Adhesion Molecule-1; Lipids; Male; Malondialdehyde; Mice; Mice, Inbred Strains; Mice, Knockout; Nitric Oxide; Phytotherapy; Plant Extracts; Prunella; Transforming Growth Factor beta1; Tunica Intima; Tunica Media; Tyrosine; Vascular Cell Adhesion Molecule-1; Vasodilation

The article deals with studying the degree of increase of the von Willebrand factor and the concentration of endothelin-1 in blood plasma in the subgroups of patients with diabetes mellitus formed depending on of type of disease and presence of phenotype with affection of kidneys. The sampling of 176 patients with diabetes mellitus (65 patients with diabetes mellitus type 1, 111 patients with diabetes mellitus type II) was examined. The control group consisted of 30 healthy persons. In the capacity of biochemical markers of endothelium dysfunction the activity of the von Willebrand factor and the concentration of endothelin-1 in blood were considered. In all patients with diabetes mellitus the biochemical characteristics of endothelium dysfunction are present manifesting by increase of concentration of endothelin-1 in blood which is especially expressed under disease phenotype with affection of kidneys. Despite of the apparent lesion of endothelium in patients with diabetes mellitus compromised with diabetic nephropathy the thrombocytes aggregation induced by ristomicine does not undergo natural changes. Hence, to consider in these patients the increasing activity of the von Willebrand factor as a reliable marker of endothelium dysfunction is not seemed possible.

Topics: Adult; Aged; Biomarkers; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelin-1; Endothelium, Vascular; Female; Humans; Male; Middle Aged; Platelet Aggregation; von Willebrand Factor

The study aim was to investigate NOS3 VNTR, NOS3 G894T, EDN1 C8002T, ACE I/D, AGT M235T and AGTR1 A1166C in nonobese and obese T2DM patients, and their interaction with the incidence of microangiopathy. T2DM subjects (n=250; 166 nonobese, and 84 obese) were genotyped for the gene variants by PCR/RFLP. The interaction of these polymorphisms with obesity and their contribution to microangiopathy were analyzed by multivariate regression analysis. A higher frequency of NOS3 4a allele was found in obese (P=0.027) vs. nonobese subjects. ACE D (P=0.009) and AGT 235T (P=0.026) alleles were associated with the reduced risk of diabetic nephropathy in nonobese and obese patients, respectively. In obese subjects, NOS3 4a (P=0.011) had a converse effect to NOS3 894T (P=0.043), and EDN1 8002T (P=0.035) on the prevalence of combined microangiopathy (neuropathy/retinopathy/nephropathy) vs. microangiopathy-negative subjects. The study indicates association of RAS variants with obesity and nephropathy, and an opposite effect of NOS3 VNTR and NOS3 G894T on the occurrence of combined microangiopathy.

Topics: Adult; Aged; Aged, 80 and over; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Endothelin-1; Female; Humans; Male; Middle Aged; Nitric Oxide Synthase Type III; Obesity; Polymorphism, Genetic; ras Proteins; Receptor, Angiotensin, Type 1

Endothelin (ET)-1 is a vasoconstrictor and proinflammatory peptide that may interfere with glucose uptake. Our objective was to investigate whether exogenous ET-1 affects glucose uptake in the forearm of individuals with insulin resistance and in cultured human skeletal muscle cells.. Nine male subjects (aged 61 ± 3 years) with insulin resistance (M value <5.5 mg/kg/min or a homeostasis model assessment of insulin resistance index >2.5) participated in a protocol using saline infusion followed by ET-1 infusion (20 pmol/min) for 2 h into the brachial artery. Forearm blood flow (FBF), endothelium-dependent vasodilatation, and endothelium-independent vasodilatation were assessed. Molecular signaling and glucose uptake were determined in cultured skeletal muscle cells.. ET-1 decreased forearm glucose uptake (FGU) by 39% (P < 0.05) after the 2-h infusion. ET-1 reduced basal FBF by 36% after the 2-h infusion (P < 0.05) and impaired both endothelium-dependent vasodilatation (P < 0.01) and endothelium-independent vasodilatation (P < 0.05). ET(A) and ET(B) receptor expression was detected on cultured skeletal muscle cells. One-hour ET-1 incubation increased glucose uptake in cells from healthy control subjects but not from type 2 diabetic patients. Incubation with ET-1 for 24 h reduced glucose uptake in cells from healthy subjects. ET-1 decreased insulin-stimulated Akt phosphorylation and increased phosphorylation of insulin receptor substrate-1 serine 636.. ET-1 not only induces vascular dysfunction but also acutely impairs FGU in individuals with insulin resistance and in skeletal muscle cells from type 2 diabetic subjects. These findings suggest that ET-1 may contribute to the development of insulin resistance in skeletal muscle in humans.

Topics: Aged; Cells, Cultured; Diabetes Mellitus, Type 2; Endothelin-1; Forearm; Glucose; Humans; Insulin Resistance; Male; Middle Aged; Muscle, Skeletal; Regional Blood Flow

Transient receptor potential vanilliod 1 (TRPV1) channels have recently been postulated to play a role in the vascular complications/consequences associated with diabetes despite the fact that the mechanisms through which TRPV1 regulates vascular function are not fully known. Accordingly, our goal was to define the mechanisms by which TRPV1 channels modulate vascular function and contribute to vascular dysfunction in diabetes. We subjected mice lacking TRPV1 [TRPV1((-/-))], db/db, and control C57BLKS/J mice to in vivo infusion of the TRPV1 agonist capsaicin or the α-adrenergic agonist phenylephrine (PE) to examine the integrated circulatory actions of TRPV1. Capsaicin (1, 10, 20, and 100 μg/kg) dose dependently increased MAP in control mice (5.7 ± 1.6, 11.7 ± 2.1, 25.4 ± 3.4, and 51.6 ± 3.9%), which was attenuated in db/db mice (3.4 ± 2.1, 3.9 ± 2.1, 7.0 ± 3.3, and 17.9 ± 6.2%). TRPV1((-/-)) mice exhibited no changes in MAP in response to capsaicin, suggesting the actions of this agonist are specific to TRPV1 activation. Immunoblot analysis revealed decreased aortic TRPV1 protein expression in db/db compared with control mice. Capsaicin-induced responses were recorded following inhibition of endothelin A and B receptors (ET(A) /ET(B)). Inhibition of ET(A) receptors abolished the capsaicin-mediated increases in MAP. Combined antagonism of ET(A) and ET(B) receptors did not further inhibit the capsaicin response. Cultured endothelial cell exposure to capsaicin increased endothelin production as shown by an endothelin ELISA assay, which was attenuated by inhibition of TRPV1 or endothelin-converting enzyme. TRPV1 channels contribute to the regulation of vascular reactivity and MAP via production of endothelin and subsequent activation of vascular ET(A) receptors. Impairment of TRPV1 channel function may contribute to vascular dysfunction in diabetes.

Topics: Adrenergic alpha-Agonists; Analysis of Variance; Animals; Azepines; Biphenyl Compounds; Blood Pressure; Capsaicin; Cells, Cultured; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dipeptides; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelial Cells; Endothelin A Receptor Antagonists; Endothelin B Receptor Antagonists; Endothelin-1; Enzyme-Linked Immunosorbent Assay; Femoral Artery; Indoles; Infusions, Intravenous; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Phenylephrine; Receptor, Endothelin A; Receptor, Endothelin B; TRPV Cation Channels; Vasoconstriction; Vasoconstrictor Agents

Diabetes is a risk factor for female sexual dysfunction (FSD). FSD has several etiologies, including a vasculogenic component that could be exacerbated in diabetes. The internal pudendal artery supplies blood to the vagina and clitoris and diabetes-associated functional abnormalities in this vascular bed may contribute to FSD.. The Goto-Kakizaki (GK) rat is a non-obese model of type 2 diabetes with elevated endothelin-1 (ET-1) activity. We hypothesize that female GK rats have diminished sexual responses and that the internal pudendal arteries demonstrate increased ET-1 constrictor sensitivity.. Female Wistar and GK rats were used. Apomorphine (APO)-mediated genital vasocongestive arousal (GVA) was measured. Functional contraction (ET-1 and phenylephrine) and relaxation (acetylcholine, ACh) in the presence or absence of the ETA receptor antagonist (ETA R; atrasentan) or Rho-kinase inhibitor (Y-27632) were assessed in the internal pudendal and mesenteric arteries. Protein expression of ET-1 and RhoA/Rho-kinase signaling pathway was determined in the internal pudendal and mesenteric arteries.. APO-mediated GVAs; contraction and relaxation of internal pudendal and mesenteric arteries; ET-1/RhoA/Rho-kinase protein expression.. GK rats demonstrated no APO-induced GVAs. Internal pudendal arteries, but not mesenteric arteries, from GK rats exhibited greater contractile sensitivity to ET-1 compared with Wistar arteries. ETA R blockade reduced ET-1-mediated constriction in GK internal pudendal and mesenteric arteries. Rho-kinase inhibition reduced ET-1-mediated constriction of GK internal pudendal but not mesenteric arteries; however, it had no effect on arteries from Wistar rats. RhoA protein expression was elevated in GK internal pudendal arteries. At the highest concentrations, ACh-mediated relaxation was greater in the GK internal pudendal artery; however, no difference was observed in the mesenteric artery.. Female GK rats demonstrate decreased sexual responses that may be because of increased constrictor sensitivity to the ET-1/RhoA/Rho-kinase signaling in the internal pudendal artery.

Topics: Animals; Apomorphine; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Endothelin-1; Estradiol; Female; Mesenteric Arteries; Rats; Rats, Inbred Strains; Rats, Wistar; rhoA GTP-Binding Protein; Sexual Behavior, Animal; Signal Transduction; Vagina; Vasoconstriction

Diabetic nephropathy is associated with cardiovascular morbidity. Angiotensin-converting enzyme (ACE) inhibitors provide imperfect renoprotection in advanced type 2 diabetes, and cardiovascular risk remains elevated. Endothelin (ET)-1 has a role in renal and cardiac dysfunction in diabetes. Here, we assessed whether combination therapy with an ACE inhibitor and ET(A) receptor antagonist provided reno- and cardioprotection in rats with overt type 2 diabetes. Four groups of Zucker diabetic fatty (ZDF) rats were treated orally from 4 (when proteinuric) to 8 mo with vehicle, ramipril (1 mg/kg), sitaxsentan (60 mg/kg), and ramipril plus sitaxsentan. Lean rats served as controls. Combined therapy ameliorated proteinuria and glomerulosclerosis mostly as a result of the action of ramipril. Simultaneous blockade of ANG II and ET-1 pathways normalized renal monocyte chemoattractant protein-1 and interstitial inflammation. Cardiomyocyte loss, volume enlargement, and capillary rarefaction were prominent abnormalities of ZDF myocardium. Myocyte volume was reduced by ramipril and sitaxsentan, which also ameliorated heart capillary density. Drug combination restored myocardial structure and reestablished an adequate capillary network in the presence of increased cardiac expression of VEGF/VEGFR-1, and significant reduction of oxidative stress. In conclusion, in type 2 diabetes concomitant blockade of ANG II synthesis and ET-1 biological activity through an ET(A) receptor antagonist led to substantial albeit not complete renoprotection, almost due to the ACE inhibitor. The drug combination also showed cardioprotective properties, which however, were mainly dependent on the contribution of the ET(A) receptor antagonist through the action of VEGF.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Glucose; Body Weight; Cell Count; Collagen Type III; Diabetes Mellitus, Type 2; Endothelin A Receptor Antagonists; Endothelin-1; Heart; Hemodynamics; Immunohistochemistry; Kidney; Kidney Function Tests; Male; Muscle Cells; Myocardium; Rats; Rats, Zucker; Real-Time Polymerase Chain Reaction; Receptors, Vascular Endothelial Growth Factor; Survival; Tyrosine; Vascular Endothelial Growth Factor A

Endothelin (ET)-1 and angiotensin II (Ang II) are likely candidates for a key role in diabetic vascular complications. We demonstrated previously that an enhanced ET-1-induced contraction is present in mesenteric arteries from Goto-Kakizaki (GK) rats at the chronic stage of type 2 diabetes. Here, we investigated whether short-term treatment of such rats with losartan, an angiotensin type 1 receptor antagonist, might normalize the ET-1-induced contraction. In mesenteric arteries from GK rats at the chronic stage (34-38 weeks) (vs. those from age-matched control Wistar rats): (1) the ET-1-induced contraction was enhanced, (2) the levels of ET-1 and Ang II were increased, (3) ET-1-stimulated ERK2 phosphorylation was increased, and (4) the ACh-induced endothelium-dependent relaxation was reduced. Mesenteric arteries isolated from such GK rats following treatment with losartan (25mg/kg/day for 2 weeks) exhibited reduced ET-1- and Ang II-induced contractions, suppressed ET-1-stimulated ERK phosphorylation, and increased ACh-induced relaxation, while the rats exhibited normalized plasma NO metabolism and their mesenteric arteries exhibited increased basal NO formation. However, such losartan treatment did not alter the increased levels of ET-1 and Ang II seen in GK mesenteric arteries. Our data suggest that within the timescale studied here, losartan normalizes ET-1-induced mesenteric artery contraction through a suppression of ERK activities and/or by normalizing endothelial function.

Topics: Angiotensin II Type 1 Receptor Blockers; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Endothelin-1; Insulin; Losartan; Male; Mesenteric Arteries; Muscle Contraction; Muscle, Smooth, Vascular; Nitric Oxide Synthase; Rats; Rats, Mutant Strains; Rats, Wistar; Receptor, Angiotensin, Type 1

The roles of endothelin-1 (ET-1) and oxidative stress causing vascular injury in the pathogenesis of diabetic neuropathy are debatable. The present study was undertaken to clarify the possible effects of oxidative stress and ET-1 in diabetic patients with and without peripheric neuropathy.. We studied plasma ET-1, nitric oxide (NO), catalase, glutathione (GSH) levels of fifty (22 females, 28 males) patients with Type 2 diabetes in order to evaluate endothelial dysfunction and oxidative stress. The neuropathy types (motor, sensorial and sensorimotor), comorbid diseases, antidiabetic treatments, smoking, diabetes duration were also considered. Short McGill Pain Questionnaire (SF-MPQ) was also performed for patients with neuropathy.. There were no significant differences between patients with (n=23) and without (n=27) neuropathy with regards to demographic features except diabetic disease duration. The statistical analysis was done considering this difference. Although NO and ET-1 levels were higher, and catalase and GSH levels were decreased in neuropathic patients, no statistical significancy was found. We also couldn't find any correlations between the parameters and SF-MPQ scores.. Although there were no relationships between neuropathy and the studied parameters, we found lower levels of catalase and GSH as intracelluler antioxidants and higher NO and ET-1 as markers of endothelial injury in patients with neuropathy. Our data suggest that there is a need of further studies with larger study groups in order to clear out the role of endothelial injury and oxidative status in the pathogenesis of diabetic neuropathy.

Topics: Adult; Aged; Catalase; Diabetes Mellitus, Type 2; Diabetic Neuropathies; Endothelin-1; Endothelium; Female; Glutathione; Humans; Male; Middle Aged; Neuralgia; Nitric Oxide; Oxidative Stress; Surveys and Questionnaires

Insulin-mediated glucose disposal is dependent on the vasodilator effects of insulin. In type 2 diabetes, insulin-stimulated vasodilation is impaired as a result of an imbalance in NO and ET-1 production. We tested the hypothesis that chronic voluntary wheel running (RUN) prevents impairments in insulin-stimulated vasodilation associated with obesity and type 2 diabetes independent of the effects of RUN on adiposity by randomizing Otsuka Long Evans Tokushima Fatty (OLETF) rats, a model of hyperphagia-induced obesity and type 2 diabetes, to 1) RUN, 2) caloric restriction (CR; diet adjusted to match body weights of RUN group), or 3) sedentary control (SED) groups (n = 8/group) at 4 wk. At 40 wk, NO- and ET-1-mediated vasoreactivity to insulin (1-1,000 μIU/ml) was assessed in the presence of a nonselective ET-1 receptor blocker (tezosentan) or a NO synthase (NOS) inhibitor [N(G)-nitro-L-arginine methyl ester (L-NAME)], respectively, in second-order arterioles isolated from the white portion of the gastrocnemius muscle. Body weight, fasting plasma glucose, and hemoglobin A1c were lower in RUN and CR than SED (P < 0.05); however, the glucose area under the curve (AUC) following the intraperitoneal glucose tolerance test was lower only in the RUN group (P < 0.05). Vasodilator responses to all doses of insulin were greater in RUN than SED or CR in the presence of a tezosentan (P < 0.05), but group differences in vasoreactivity to insulin with coadministration of L-NAME were not observed. We conclude daily wheel running prevents obesity and type 2 diabetes-associated declines in insulin-stimulated vasodilation in skeletal muscle arterioles through mechanisms that appear to be NO mediated and independent of attenuating excess adiposity in hyperphagic rats.

Topics: Adiposity; Animals; Arterioles; Blood Glucose; Body Composition; Body Weight; Caloric Restriction; Diabetes Mellitus, Type 2; Disease Models, Animal; Eating; Endothelin-1; Enzyme Inhibitors; Glycated Hemoglobin; Hyperphagia; Immunohistochemistry; Insulin; Insulin Resistance; Male; Motor Activity; Muscle, Skeletal; Nitric Oxide; Nitric Oxide Synthase Type III; Obesity; Phosphorylation; Rats; Rats, Inbred OLETF; Running; Time Factors; Vasodilation

To (i) investigate expression of the endothelin-1 (ET-1) gene in peripheral blood mononuclear cells (PBMCs) of patients with type 2 diabetes mellitus (DM) and (ii) determine what correlations, if any, exist between expression of ET-1 in patients with type 2 DM and treatment, clinical features, and biochemical markers in diabetic retinopathy (DR).. The study group included 58 patients with type 2 DM, subdivided into three subgroups: those without DR (n=19), those with nonproliferative DR (NPDR; n=28), and those with proliferative DR (PDR; n=11). The control group consisted of 60 individuals. In all groups the mRNA level of ET-1 was estimated using real-time quantitative reverse transcription PCR.. The mRNA level of ET-1 in patients with NPDR was significantly higher than in those without DR. An increase in ET-1 expression was observed in patients with PDR as opposed to those without DR. Compared to controls, the mRNA level of ET-1 was significantly higher both in patients with NPDR and those with PDR. Duration of DM, insulin therapy, and serum creatinine levels were associated with increased mRNA level of ET-1, whereas medication with sulfonylurea or angiotensin-converting enzyme inhibitors had the opposite effect.. Expression of ET-1 in PBMCs may be associated with severity of DR in patients with type 2 DM. Long-standing clinical course of DR; medication with insulin, sulfonylurea, or ACE inhibitors; and serum creatinine levels are factors possibly associated with changes in ET-1 expression in PBMCs.

Topics: Adult; Aged; Aged, 80 and over; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Endothelin-1; Female; Gene Dosage; Gene Expression Regulation; Humans; Male; Middle Aged; RNA, Messenger

Diabetes increases the risk of as well as poor outcome after stroke. Matrix metalloprotease (MMP) activation disrupts blood-brain barrier integrity after cerebral ischemia. We have previously shown that type 2 diabetes promotes remodeling of middle cerebral arteries (MCA) characterized by increased media/lumen (M/L) ratio and MMP activity in an endothelin (ET)-1-dependent manner in the Goto-Kakizaki (GK) rat model. In the present study, we examined the effects of ET-1-mediated vascular remodeling on neurovascular damage following cerebral ischemic injury in GK rats 5 and 12 weeks after the onset of diabetes. The MCA structure, cerebral perfusion as well as infarct size, and hemorrhage were measured in control and diabetic rats subjected to transient MCA occlusion. M/L ratio was increased after 12 but not 5 weeks of diabetes. The baseline cerebral perfusion was lower and the infarct volume smaller in diabetic rats in both age groups. The incidence of hemorrhagic transformation was higher after 5 weeks of diabetes as compared to that after 12 weeks or in the control groups. These findings provide evidence that ET-1-mediated cerebrovascular remodeling does not worsen the neurovascular damage of ischemic brain injury in diabetes. It is possible that this early remodeling response is compensatory in nature to regulate vascular tone and integrity, especially when ischemia is layered on diabetic vascular disease.

Topics: Animals; Blood Glucose; Cerebral Hemorrhage; Cerebral Infarction; Cerebrovascular Circulation; Collagen; Diabetes Mellitus, Type 2; Disease Models, Animal; Endothelin-1; Male; Middle Cerebral Artery; Rats; Rats, Inbred Strains; Rats, Wistar; Reperfusion Injury; Tunica Media

Experimental studies confirmed that reactive oxygen species increase endothelin-1 (ET-1) synthesis, and modulate ET-1 signaling pathway resulting in vasoconstriction and vascular remodeling. The aim of this study was to evaluate the relationship between plasma ET-1 concentration and antioxidant status in patients with essential hypertension and type 2 diabetes mellitus.. 78 hypertensive patients, 53.8% diabetic, mean age 72.1+/-7.07 were examined. The plasma concentration of glucose, creatinine, uric acid, bilirubin, cholesterol, insulin, HbA1c and ET-1 were measured. Antioxidant status was assessed by Ferric Reducing Ability of Plasma (FRAP), vitamin C concentration and erythrocyte superoxide dismutase (SOD) activity.. With diabetes ET-1 concentration was higher (1.35+/-0.51 vs 1.12+/-0.46 pg/mL, p=0.04). The negative correlations between ET-1 concentration and FRAP (r=-0.50, p<0.0001), vitamin C (r=-0.296, p=0.01) and SOD (r=-0.44, p=0.001) were found. Concentration of ET-1 correlated positively with SBP (r=0.33, p=0.005) but not with DBP. The relationship between DBP and ET-1 only in subjects with DBP>110 mm Hg and FRAP<0.40 mmol/L was found. In multiple regression analysis plasma ET-1 levels were associated independently with FRAP (beta=-0.583, p=0.003) and plasma vitamin C (beta=-0.407, p=0.04).. In hypertensive and diabetic patients higher plasma endothelin-1 level was independently associated with lower plasma antioxidant status measured by FRAP and decreased vitamin C concentration, which may be a result of increased oxidative stress in these diseases.

Topics: Aged; Antihypertensive Agents; Antioxidants; Ascorbic Acid; Blood Pressure; Diabetes Mellitus, Type 2; Endothelin-1; Erythrocytes; Female; Humans; Hypertension; Male; Protein Kinases; Regression Analysis; Superoxide Dismutase; TOR Serine-Threonine Kinases

Medial thickening and vascular hypertrophy of resistance arteries can lead to cardiovascular complications associated with diabetes. While previous studies have established a role of type 1 diabetes in vascular remodeling, we recently extended these observations to type 2 diabetes and reported increased collagen deposition due to alterations in matrix metalloproteinase expression and activity in mesenteric resistance arteries. These studies also showed that remodeling response was mediated by endothelin-1 (ET-1) via activation of ET(A) receptors, whereas blockade of ET(B) receptors exacerbated the remodeling. However, the effectiveness of glycemic control strategies in preventing these vascular changes, including activation of the ET system still remained unclear. Also, very little is known about whether and to what extent reorganization of the extracellular matrix (ECM) affects vascular compliance and vasomotor tone. Accordingly, this study assessed structural remodeling of mesenteric microvessels, vascular compliance, and myogenic tone, as well as the role of matrix metalloproteinases (MMP) in mediating these processes. Spontaneously diabetic, non-obese Goto-Kakizaki (GK) rats, a model for type 2 diabetes, and normoglycemic Wistar rats were used for the studies. A subset of GK rats were administered metformin to achieve euglycemia. Glycemic control normalized the increased media-to-lumen ratios (M/L) and myogenic tone seen in diabetes, as well as normalizing plasma ET-1 levels and mesenteric ET(A) receptor expression. There was increased collagen synthesis in diabetes paralleled by decreased collagenase MMP-13 activity, while glycemic control attenuated the process. These findings and our previous study taken together suggest that hyperglycemia-mediated activation of ET-1 and ET(A) receptors alter vascular structure and mechanics in type 2 diabetes.

Topics: Animals; Blood Glucose; Collagen; Diabetes Mellitus, Type 2; Disease Models, Animal; Endothelin-1; Hyperplasia; Hypoglycemic Agents; Male; Matrix Metalloproteinase 13; Mesenteric Arteries; Metformin; Microvessels; Rats; Rats, Wistar; Receptor, Endothelin A; Receptor, Endothelin B; Vasoconstriction

Endothelin (ET)-1 is a likely candidate for a key role in diabetic vascular complications. However, no abnormalities in the vascular responsiveness to ET-1 have been identified in the chronic stage of type 2 diabetes. Our goal was to look for abnormalities in the roles played by ET receptors (ET(A) and ET(B)) in the mesenteric artery of the type 2 diabetic Goto-Kakizaki (GK) rat and to identify the molecular mechanisms involved. Using mesenteric arteries from later-stage (32-38 wk old) individuals, we compared the ET-1-induced contraction and the relaxation induced by the selective ET(B) receptor agonist IRL1620 between GK rats and control Wistar rats. Mesenteric artery ERK activity and the protein expressions for ET receptors and MEK were also measured. In GK rats (vs. age-matched Wistar rats), we found as follows. 1) The ET-1-induced contraction was greater and was attenuated by BQ-123 (ET(A) antagonist) but not by BQ-788 (ET(B) antagonist). In the controls, BQ-788 augmented this contraction. 2) Both the relaxation and nitric oxide (NO) production induced by IRL1620 were reduced. 3) ET-1-induced contraction was enhanced by N(G)-nitro-l-arginine (l-NNA; NO synthase inhibitor) but suppressed by sodium nitroprusside (NO donor). 4) The enhanced ET-1-induced contraction was reduced by MEK/ERK pathway inhibitors (PD-98059 or U0126). 5) ET-1-stimulated ERK activation was increased, as were the ET(A) and MEK1/2 protein expressions. 6) Mesenteric ET-1 content was increased. These results suggest that upregulation of ET(A), a defect in ET(B)-mediated NO signaling, and activation of the MEK/ERK pathway together represent a likely mechanism mediating the hyperreactivity to ET-1 examined in this study.

Topics: Angiotensin II; Animals; Arginine Vasopressin; Butadienes; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Disease Models, Animal; Disease Progression; Dose-Response Relationship, Drug; Endothelin-1; Endothelins; Enzyme Inhibitors; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Male; MAP Kinase Kinase Kinases; Mesenteric Arteries; Nitric Oxide; Nitric Oxide Donors; Nitric Oxide Synthase; Nitriles; Nitroarginine; Nitroprusside; Oligopeptides; Peptide Fragments; Peptides, Cyclic; Piperidines; Rats; Rats, Wistar; Receptor, Endothelin A; Receptor, Endothelin B; Signal Transduction; Vasoconstriction; Vasodilation

Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia and dyslipidemia. The abnormalities in nutrient metabolism and elevated inflammatory mediators resulting from DM lead to impairment of wound healing and vulnerability to infection and foot ulcers. Diabetic lower limb ischemia often leads to limb necrosis. Lower extremity bypass surgery (LEBS) is indicated to prevent limb loss in patients with critical leg ischemia. This study investigated the alteration of inflammatory and endothelium dysfunction markers before and after LEBS in DM patients. Twenty one type 2 DM patients with LEBS were included. Blood was drawn before and at 1 day and 7 days after surgery in the patients. Plasma soluble cellular adhesion molecule levels and blood leukocyte integrin expressions were measured. Also, plasma concentrations of endothelin-1 and nitric oxide were analyzed to evaluate the vascular endothelial function. The results showed that there were no significant differences in plasma cellular adhesion molecules, endothelin-1 and nitric oxide levels, nor did any differences in leukocyte integrin expressions before and after the operation. These results suggest that the efficacy of LEBS on alleviating inflammatory reaction and improving endothelial function in DM patients was not obvious.

Topics: Aged; Biomarkers; Cell Adhesion Molecules; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Female; Humans; Inflammation; Integrins; Ischemia; Leg; Leukocytes; Male; Middle Aged; Nitric Oxide; Postoperative Period

Evolving research suggests that common and rare alleles jointly constitute the genetic landscape of complex disease. We studied the association between 43 pathway-related candidate genes with 'intermediate phenotype' (i.e. corresponding plasma protein) and diabetic nephropathy in a customised microarray of 1,536 SNPs.. In this case-control study of type 2 diabetic Chinese individuals with and without diabetic nephropathy, cases (n = 545) were defined on the basis of a spot urinary albumin/creatinine ratio (ACR) > 113 mg/mmol; the value for controls (n = 503) was ACR < 3.3 mg/mmol. Genotyping was performed using Illumina GoldenGate assay.. No single nucleotide polymorphism (SNP) remained significant in single locus analysis after correction for multiple testing. Therefore, we explored the best approximately 1% SNPs. Of these 13 SNPs, four clustered to a 5' end NADPH oxidase homologue 4 (NOX4) haplotype (GGCC frequency = 0.776) with estimated OR for diabetic nephropathy of 2.05 (95% CI 1.04-4.06) (heterozygous) and 2.48 (1.27-4.83) (homozygous) (p = 0.0055). The haplotype was correlated with plasma Cu/Zn superoxide dismutase (SOD) concentration, suggesting increased oxidative burden. Endothelin-1 SNP (rs1476046G>A, frequency = 0.252) was correlated with plasma C-terminal pro-endothelin-1 concentrations with an estimated OR for diabetic nephropathy of (heterozygous) 1.26 (0.96-1.66) and (homozygous) 1.87 (1.13-3.12) (p = 0.0072). Nitric oxide synthase 1 (NOS1) 5' haplotype (TGTC frequency = 0.38) also revealed a suggestive association with diabetic nephropathy: heterozygous 1.26 (0.95-1.67), homozygous 1.57 (1.04-2.35) (p = 0.0073). A rare NADPH oxidase homologue 1 (NOX1)-coding non-synonymous SNP (Arg315His, frequency = 0.006) was found exclusively among cases.. Our preliminary observations suggest that common haplotypes from NOX4 and endothelin-1 SNP correlated with plasma Cu/Zn SOD and C-terminal pro-endothelin-1 concentrations, respectively, and might have conferred diabetic nephropathy susceptibility. Common NOS1 and rare NOX1 variants also revealed a suggestive association with diabetic nephropathy. Future studies to validate our observation are needed.

Topics: Aged; Asian People; Blood Proteins; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelin-1; Female; Genetic Predisposition to Disease; Haplotypes; Humans; Male; Middle Aged; NADPH Oxidase 4; NADPH Oxidases; Nitric Oxide Synthase Type I; Oligonucleotide Array Sequence Analysis; Polymorphism, Single Nucleotide; Singapore

The increased cardiovascular risk in diabetes has been linked to endothelial and renal dysfunction. The aim of this study was to investigate the role of stable fragments of the precursors of adrenomedullin, endothelin-1, vasopressin, and atrial natriuretic peptide in progression of cardiovascular disease in patients with diabetes.. This was a prospective, observational study design with a composite end point (death or unexpected admission to hospital due to a cardiovascular event) on 781 patients with type 2 diabetes (54 events, median duration of observation 15 months). The four stable precursor peptides midregional adrenomedullin (MR-proADM), midregional proatrial natriuretic peptide (MR-proANP), COOH-terminal proendothelin-1 (CT-proET-1), and COOH-terminal provasopressin or copeptin (CT-proAVP) were determined at baseline, and their association to renal function and cardiovascular events was studied using stepwise linear and Cox logistic regression analysis and receiver operating characteristic analysis, respectively.. MR-proADM, CT-proET-1, CT-proAVP, and MR-proANP were all elevated in patients with future cardiovascular events and independently correlated to serum creatinine. MR-proADM and MR-proANP were significant predictors of a future cardiovascular event, with MR-proANP being the stronger (area under the curve 0.802 +/- 0.034, sensitivity 0.833, specificity 0.576, positive predictive value 0.132, and negative predictive value 0.978 with a cutoff value of 75 pmol/l).. The four serum markers of vasoactive and natriuretic peptides are related to both kidney function and cardiovascular events, thus linking two major complications of diabetes, diabetic nephropathy and cardiovascular disease.

Topics: Adrenomedullin; Atrial Natriuretic Factor; Cardiovascular Diseases; Creatinine; Diabetes Mellitus, Type 2; Endothelin-1; Female; Glycopeptides; Humans; Kidney; Male; Middle Aged; Proportional Hazards Models; Prospective Studies; Protein Precursors

To establish a method for isolation and culture of subcutaneous microvascular endothelial cells (MVEC) from small human tissue biopsies to compare gene and protein expression of insulin signaling molecules in MVEC from insulin-resistant and healthy control subjects.. Stromavascular cells from subcutaneous needle biopsies of type 2 diabetic and control subjects were expanded in culture and the endothelial cells selected with magnetic immune separation. Western blots and RT-PCR were used for protein and gene expression assays.. At least 99% of the expanded primary MVEC could be characterized as endothelial cells. The expression of insulin receptors was low, but insulin increased tyrosine phosphorylation of both the insulin receptor and insulin receptor substrate (IRS)-1 and activated protein kinase B (PKB). The IRS-1 protein expression was reduced and the serine phosphorylation of PKB in response to insulin attenuated whereas basal and insulin-stimulated phosphorylation of extracellular signal-related kinase (ERK)1/2 was increased in type 2 diabetes MVEC. Endothelin (ET)-1 mRNA levels were significantly higher in type 2 diabetes cells. The addition of ET-1 increased the phosphorylation of mitogen-activated protein kinase (MAPK), an effect antagonized by the MEK-1 inhibitor PD98059. Furthermore, the endothelin ET(A) and ET(B) receptor antagonists BQ123 and BQ788 decreased basal MAPK activity in type 2 diabetes MVEC and prevented the ET-1-induced activation.. We developed a system for isolation and culture of human MVEC from small needle biopsies. Our observations support the concept of "selective" insulin resistance, involving IRS-1 and the PI3kinase pathway, as an underlying factor for a dysregulated microvascular endothelium in type 2 diabetes. Our data also support a role of ET-1 for the increased MAPK activity seen in nonstimulated type 2 diabetes MVEC.

Topics: Adipose Tissue; Biopsy, Needle; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Enzyme Activation; Gene Expression Regulation; Humans; Insulin; Insulin Receptor Substrate Proteins; Microcirculation; Mitogen-Activated Protein Kinase Kinases; Phosphoserine; Proto-Oncogene Proteins c-akt; Receptor, Insulin; Reference Values

Urate, a naturally-occurring antioxidant, is a marker/factor for cardiovascular disease. Hyperuricaemia is associated with IR, MetS and endothelial dysfunction. We characterised the associations between neurohormones, uricaemia, and glucose homeostasis in type 2 diabetes mellitus (T2DM) males. Cross-sectional; 705 T2DM males divided into two groups: uric acid < 7.0 mg/dl (normouricaemic; n=476) versus uric acid >or= 7.0 mg/dl (hyperuricaemic; n=229). HOMA beta-cell function (B), insulin sensitivity (S), hyperbolic product (BxS), and (BxS) loss rate were determined alongside neurohormones (Nt-proANP, BNP, Big ET-1 and UII). Mean age and diabetes duration were not different between groups. Hyperuricaemics had more macroangiopathy, total/central adiposity, IR, hypertension, dyslipidemia and MetS prevalence. Nt-proANP and BNP levels were more than twice as high in hyperuricaemics, whereas Big ET-1 and UII were higher by 46% and 14%, respectively. HOMA (BxS) was higher in hyperuricaemics: 31 (16)% vs. 26 (18)% (p=0.0004). BxS loss rate was faster in normouricaemics: 1.36 (0.54)% vs. 1.20 (0.43)%/year(-1) (p<0.0001 ). The proportion with HbA(1C) < 7.0% was 39% (normouricaemics) vs. 49% (hyperuricaemics; p=0.0091). In T2DM males, hyperuricaemia is associated with raised neurohormones together with better beta-cell indices. Urate's dual properties may translate into beneficial (glucose homeostasis) and detrimental (raised neurohormones) effects.

Topics: Aged; Atrial Natriuretic Factor; Biomarkers; Blood Glucose; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Endothelin-1; Glycated Hemoglobin; Humans; Hyperuricemia; Insulin; Insulin-Secreting Cells; Male; Metabolic Syndrome; Middle Aged; Natriuretic Peptide, Brain; Up-Regulation; Uric Acid

Insulin resistance involves decreased phosphorylation of insulin receptor substrate (IRS) proteins and (or) Akt. In the vasculature, modulated Akt phosphorylation may cause impaired vasorelaxation via decreased eNOS activation. Diet-induced insulin resistance enhances endothelin-1(ET-1)-mediated vasoconstriction and prevents vasodilatation to insulin. Presently, we evaluated insulin-mediated vascular relaxation, assessed molecular markers of the insulin signaling pathway, and determined the involvement of ET-1 in response to insulin by using selective ETA- or ETB-receptor blockade in a lean model of type 2 diabetes. Dose-response curves to insulin (0.01-100 ng/mL) were generated with wire myograph using thoracic aorta rings from control Wistar or diabetic Goto-Kakizaki (GK) rats (n=3-11). Maximal relaxation (Rmax) to insulin was significantly impaired and insulin sensitivity was decreased in the GK group. Preincubation with 1 micromol/L BQ-123 or BQ-788 for ETA- and ETB-receptor blockade, respectively, resulted in improved insulin sensitivity. Immunoblotting for native and phosphorylated Akt and IRS-1 revealed a decrease in Akt activation in the GK group. In vivo hyperinsulinemic euglycemic clamp studies showed decreased glucose utilization in GK rats, indicative of insulin resistance. These findings provide evidence that vascular insulin resistance occurs in a nonobese model of diabetes and that both ET receptor subtypes are involved in vascular relaxation to insulin.

Topics: Adaptor Proteins, Signal Transducing; Animals; Aorta, Thoracic; Diabetes Mellitus, Type 2; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelin-1; Glucose Clamp Technique; In Vitro Techniques; Insulin; Male; Phosphorylation; Rats; Rats, Wistar; Receptor, Endothelin A; Receptor, Endothelin B; Receptor, Insulin; Signal Transduction; Vasodilation

The aim of this study was to evaluate the possible association between serum fatty acids composition and endothelial dysfunction in patients with type 2 diabetes mellitus. A cross-sectional study was conducted with 125 normo- or microalbuminuric type 2 diabetes mellitus patients with serum creatinine <1.5 mg/dL. Serum fatty acids composition (gas chromatography), serum levels of endothelin-1 (ET-1) (enzyme-linked immunosorbent assay), fibrinogen, serum C-reactive protein, lipids, homeostasis model assessment resistance index (HOMA-R), and 24-hour urinary albumin excretion rate were measured. Serum levels of ET-1 were positively correlated with saturated fatty acids (r = 0.257, P = .025) and negatively correlated with polyunsaturated fatty acids (PUFAs) (r = -0.319, P = .005). Serum ET-1 levels were also positively correlated with systolic blood pressure, waist circumference, total cholesterol levels, triglycerides, and HOMA-R. In multiple linear regression models, only saturated fatty acids (R(2) = 0.317, P = .002) or PUFAs (R(2) = 0.314, P = .001) remained associated with ET-1 levels. Models were adjusted for systolic blood pressure, HOMA-R, waist circumference, triglycerides, body mass index, and smoking habit. The serum total PUFA levels showed an inverse correlation with urinary albumin excretion rate (r = -0.248, P = .012). In conclusion, in type 2 diabetes mellitus patients, the serum fatty acids composition was independently related to endothelial function evaluated by serum ET-1. Saturated fatty acids were associated with endothelial dysfunction (high levels of ET-1), whereas PUFAs had a protective role in endothelial function.

Topics: Aged; Albuminuria; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Diet; Endothelin-1; Endothelium, Vascular; Fatty Acids; Fatty Acids, Unsaturated; Female; Humans; Male; Middle Aged

We tested the hypothesis that genetic variants in vasoactive and angiogenic factors regulating the retina vasculature contribute to the development of diabetic retinopathy (DR).. A case-control study was performed to study the genetic association between DR and polymorphic variants of EDN1 (Lys198Asn), LTA (IVS1-80C>A, IVS1-206G>C, IVS1-252A>G), eNOS (Glu298Asp), and ITGA2 (BgI II) in a Chinese population with type 2 diabetes mellitus. A well defined population with type 2 diabetes, consisting of 127 controls and 216 DR patients, was recruited.. A higher frequency of the Asn/Asn genotype of EDN1 was found in individuals with at least 10 years of diabetes and no retinopathy (controls) compared with DR patients with any duration of diabetes (DR: 2.3%; control: 11.0%; p=0.0002). The Asn allele was also more frequent in controls than DR patients (DR: 16.4%; control: 29.5%; p=0.007). Multiple logistic regression analysis showed that the Asn/Asn genotype was the factor most significantly associated with reduced risk of DR (odds ratio=0.19; 95% CI: 0.07-0.53; p=0.002) and with late onset of diabetes (Asn/Asn: 59 years; Lys/Lys + Lys/Asn: 53 years; p=0.02). Moreover, the Lys/Lys genotype was more common among patients with nonproliferative (75.7%) than proliferative DR (56.9%; p=0.008). The distributions of Lys198Asn alleles in hypertension did not differ from normotensive subjects. No associations between DR and polymorphisms of LTA, eNOS, or ITGA2 were detected, and there were no detectable gene-gene or gene-environmental interactions among the polymorphisms.. The Asn/Asn genotype of EDN1 was associated with a reduced risk of DR and with delayed onset of type 2 diabetes.

Topics: Age of Onset; Aged; Asparagine; Case-Control Studies; China; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Endothelin-1; Female; Gene Frequency; Genetic Predisposition to Disease; Genotype; Humans; Hypertension; Lysine; Male; Middle Aged; Odds Ratio; Polymorphism, Single Nucleotide; Regression Analysis

There are changes in blood flow during the clinical stages of diabetic retinopathy with increasing leukostasis and secondary elaboration of cytokines. This study evaluated the vitreous concentrations of haemodynamic-related (endothelin-1 (ET-1) and nitric oxide (NO)), inflammatory and anti-inflammatory (interleukin-1 receptor antagonist, IL-1 Ra) cytokines in the diabetic patients (with nonproliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR)), compared them with those of control patients (full thickness macular hole, FTMH) and correlated to macular structural indices.. Vitreous samples from five FTMH patients representing normal controls were analysed together with the vitreous samples of 15 patients with NPDR and five with PDR. The vitreous concentrations of nitrite (total NO), ET-1, and prostacyclin was determined using ELISA kits (R&D Systems, Minneapolis, MN, USA) according to the manufacturer's instructions. A sandwich luminescent immunoassay technique was used to determine IL-1beta and IL-1 Ra concentrations.. In the different clinical groups, there were no differences in the vitreous NO and prostacyclin concentrations. In NPDR, the median ET-1 concentration (0.7 pg/ml SD +/-0.8 pg/ml) was significantly reduced (P<0.05), compared to PDR (6.35 pg/ml SD +/-0.6 pg/ml) and FTMH (3.6 pg/ml SD +/-0.14 pg/ml). Its concentration also positively correlated with foveal thickness and macular volume (P<0.05) in patients with NPDR and macular oedema. IL-1 beta was detected in PDR, and diabetic patients demonstrated a lower concentration of the anti-inflammatory cytokine IL-1 Ra.. Reduced concentrations of ET-1 in NPDR may reflect the haemodynamic changes of NPDR. The IL-1 Ra concentration suggests a change in the anti-inflammatory environment of the diabetic retina.

Topics: Adult; Aged; Cytokines; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Endothelin-1; Enzyme-Linked Immunosorbent Assay; Epoprostenol; Humans; Inflammation Mediators; Interleukin-1beta; Macular Edema; Middle Aged; Nitric Oxide; Receptors, Interleukin-1; Vitreous Body

To evaluate the relationship between oxidative stress and endothelial dysfunction (ED) in diabetic patients without clinical macrovascular complications.. In 27 type 1, 56 type 2 diabetic patients and 35 healthy controls the redox state (GSH, GSSG; enzymatic method), endothelin-1 (ET-1; ELISA) and von Willebrand factor (vWF; ELISA) plasma levels, urinary vascular endothelial growth factor (VEGF; ELISA) were measured.. Decreased GSH levels (p<0.05, type 1 and type 2), GSH/GSSG ratio (p<0.05 type 1, p<0.001 type 2) and elevated vWF levels (p<0.001, type 1 and type 2) were observed in diabetic patients in comparison with controls. A negative correlation between GSH and vWF (p<0.02 and p<0.001, in type 1 and type 2, respectively) and GSH and BMI (p<0.02 in type 1 and type 2) was observed. ET-1 was positively correlated to age (p<0.05) and diabetes duration (p<0.03) in type 1, while vWF was correlated to systolic blood pressure (p<0.05) in type 2 diabetic patients. Urinary VEGF was higher in type 2 (p<0.05) in comparison with type 1 diabetic patients and was correlated to glycemia (p<0.05) and systolic blood pressure (p<0.05).. These data might indicate that markers of oxidative stress and ED are altered in diabetic patients without clinical macrovascular complications.

Topics: Adult; Biomarkers; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Endothelin-1; Endothelium, Vascular; Female; Glutathione; Humans; Male; Middle Aged; Oxidative Stress; Reference Values; Vascular Endothelial Growth Factor A; von Willebrand Factor

Endothelin-1 levels are elevated in patients with type 2 diabetes mellitus and may contribute to impaired microvascular function. We investigated the effect of selective endothelin-A (ET(A)) receptor blockade (BQ123) on skin microcirculation in patients with type 2 diabetes and albuminuria.. Ten type 2 diabetes patients and 8 non-diabetic controls were investigated. Nutritive skin capillary circulation, investigated by videophotometric capillaroscopy, and total skin microcirculation, assessed by laser Doppler flux-metry (LDF), were studied during intra-arterial infusion of saline for 15 min, followed by BQ123 infusion for 60 min.. Following BQ123 infusion there was a significant increase in resting capillary blood cell velocity (CBV) in patients with type 2 diabetes from 0.24 (0.20-0.34) mm/s at baseline to 0.61 (0.46-0.88) mm/s at 60 min, but no significant change in the control subjects [0.55 (0.10-0.68) vs. 0.38 (0.13-0.88) mm/s; p < 0.005 for difference between groups]. Peak CBV following arterial occlusion and skin temperature increased significantly in the type 2 diabetes group but not in the control group during BQ123 infusion. There were no significant changes in LDF parameters during infusion of BQ123 in either group.. ET(A) receptor blockade improves nutritive skin capillary circulation in patients with type 2 diabetes and microangiopathy.

Topics: Aged; Albuminuria; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Endothelin A Receptor Antagonists; Endothelin-1; Female; Humans; Male; Microcirculation; Middle Aged; Peptides, Cyclic; Skin

Approximately 40% of patients with type 2 diabetes present with concurrent hypertension at the time of diabetes diagnosis. Increases in peripheral vascular resistance and correspondingly enhanced vasoconstrictor capacity could have profound implications for the development of hypertension and the progression of insulin resistance to overt diabetes. The purpose of this study was to determine whether skeletal muscle arteriolar vasoconstrictor dysfunction precedes or occurs concurrently with the onset of diabetes and hypertension. Male Zucker diabetic fatty (ZDF) rats were studied at 7, 13, and 20 wk of age to represent prediabetic and short-term and long-term diabetic states, respectively. Conscious mean arterial pressure (MAP), fasted plasma insulin and glucose, vasoconstrictor responses, and passive mechanical properties of isolated skeletal muscle arterioles were measured in prediabetic, diabetic, and age-matched control rats. Elevated MAP was manifest in short-term diabetes (control 117 +/- 1, diabetic 135 +/- 3 mmHg) and persisted with long-term diabetes (control 113 +/- 2, diabetic 135 +/- 3 mmHg). This higher MAP was preceded by augmented arteriolar vasoconstrictor responses to norepinephrine and endothelin-1 and followed by diminished beta-adrenergic vasodilation and enhanced myogenic constriction in long-term diabetes. Furthermore, we demonstrate that diminished nitric oxide (NO) signaling underlies the increases in vasoconstrictor responsiveness in arterioles from prediabetic and diabetic rats. Arteriolar stiffness was not different between control and prediabetic or diabetic rats at any time point studied. Collectively, these results indicate that increases in vasoconstrictor responsiveness resulting from diminished NO signaling in skeletal muscle arterioles precede the development of diabetes and hypertension in ZDF rats.

Topics: Animals; Arterioles; Blood Glucose; Blood Pressure; Diabetes Mellitus, Type 2; Disease Models, Animal; Disease Progression; Dose-Response Relationship, Drug; Down-Regulation; Endothelin-1; Enzyme Inhibitors; Hypertension; Insulin; Isoproterenol; Male; Muscle, Skeletal; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Norepinephrine; Potassium Chloride; Prediabetic State; Rats; Rats, Zucker; Signal Transduction; Superoxide Dismutase; Superoxide Dismutase-1; Time Factors; Vasoconstriction; Vasoconstrictor Agents; Vasodilator Agents

Diabetes increases the risk of stroke and contributes to poor clinical outcomes in this patient population. Myogenic tone of the cerebral vasculature, including basilar arteries, plays a key role in controlling cerebral blood flow. Increased myogenic tone is ameliorated with ET receptor antagonism in Type 1 diabetes. However, the role of endothelin-1 (ET-1) and its receptors in cerebrovascular dysfunction in Type 2 diabetes, a common comorbidity in stroke patients, remains poorly elucidated. Therefore, we hypothesized that 1) cerebrovascular dysfunction occurs in the Goto-Kakizaki (GK) model of Type 2 diabetes, and 2) pharmacological antagonism of ETA receptors ameliorates, while ETB receptor blockade augments vascular dysfunction. GK or control rats were treated with antagonists to either ETA (atrasentan, 5 mg.kg(-1).day(-1)) or ETB (A-192621, 15 or 30 mg.kg(-1).day(-1)) receptors for 4 wk and vascular function of basilar arteries was assessed using a wire myograph. GK rats exhibited increased sensitivity to ET-1. ET(A) receptor antagonism caused a rightward shift, indicating decreased sensitivity in diabetes, while it increased sensitivity to ET-1 in control rats. Endothelium-dependent relaxation was impaired in diabetes. ETA receptor blockade restored relaxation to control values in the GK animals with no significant effect in Wistar rats and ETB blockade with 30 mg.kg(-1).day(-1) A-192621 caused paradoxical constriction in diabetes. These studies demonstrate that cerebrovascular dysfunction occurs and may contribute to altered regulation of myogenic tone and cerebral blood flow in diabetes. While ETA receptors mediate vascular dysfunction, ETB receptors display differential effects. These results underscore the importance of ETA/ETB receptor balance and interactions in cerebrovascular dysfunction in diabetes.

Topics: Acetylcholine; Animals; Atrasentan; Basilar Artery; Diabetes Mellitus, Type 2; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelin A Receptor Antagonists; Endothelin B Receptor Antagonists; Endothelin-1; Male; Pyrrolidines; Rats; Rats, Wistar; Receptor, Endothelin A; Receptor, Endothelin B; Vasoconstriction; Vasoconstrictor Agents; Vasodilation; Vasodilator Agents; Viper Venoms

To evaluate the relationship of plasma endothelin-1 (ET-1) levels, a marker of endothelial dysfunction, and urinary albumin excretion in patients with type 2 diabetes mellitus (DM).. Cross-sectional study was conducted in 279 patients (132 males, mean age: 58.7+/-11.0 years, mean DM duration: 11.3+/-8.1 years). Urinary albumin excretion, ET-1, and insulin were measured. Insulin sensitivity was estimated by homeostasis model assessment (HOMA-ir) index.. ET-1 was associated with urinary albumin excretion after controlling for age, gender, body mass index, blood pressure, HbA1c test, and total cholesterol (R=0.436; adjusted R(2)=0.190, P<0.01). Furthermore, there was a progressive increase in plasma ET-1 levels from patients with normoalbuminuria (n=187, 0.92+/-0.50pg/ml), microalbuminuria (n=68, 1.13+/-0.52pg/ml) to macroalbuminuria (n=24, 1.93+/-1.10pg/ml, P<0.01).. There is an independent association of plasma ET-1 levels with urinary albumin excretion. In addition, plasma ET-1 levels started to increase in the normal values of urinary albumin excretion suggesting that in patients with type 2 DM endothelial dysfunction is already present, in urinary albumin excretion values considered normal.

Topics: Age of Onset; Aged; Albuminuria; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Retinopathy; Endothelin-1; Endothelium, Vascular; Female; Humans; Male; Middle Aged

Vascular dysfunction, which presents either as an increased response to vasoconstrictors or an impaired relaxation to dilator agents, results in worsened cardiovascular outcomes in diabetes. We have established that the mesenteric circulation in Type 2 diabetes is hyperreactive to the potent vasoconstrictor endothelin-1 (ET-1) and displays increased nitric oxide-dependent vasodilation. The current study examined the individual and/or the relative roles of the ET receptors governing vascular function in the Goto-Kakizaki rat, a mildly hyperglycemic, normotensive, and nonobese model of Type 2 diabetes. Diabetic and control rats received an antagonist to either the ET type A (ETA; atrasentan; 5 mg x kg(-1) x day(-1)) or type B (ET(B); A-192621; 15 or 30 mg x kg(-1) x day(-1)) receptors for 4 wk. Third-order mesenteric arteries were isolated, and vascular function was assessed with a wire myograph. Maximum response to ET-1 was increased in diabetes and attenuated by ETA antagonism. ETB blockade with 15 mg/kg A-192621 augmented vasoconstriction in controls, whereas it had no further effect on ET-1 hyperreactivity in diabetes. The higher dose of A-192621 showed an ETA-like effect and decreased vasoconstriction in diabetes. Maximum relaxation to acetylcholine (ACh) was similar across groups and treatments. ETB antagonism at either dose had no effect on vasorelaxation in control rats, whereas in diabetes the dose-response curve to ACh was shifted to the right, indicating a decreased relaxation at 15 mg/kg A-192621. These results suggest that ETA receptor blockade attenuates vascular dysfunction and that ETB receptor antagonism exhibits differential effects depending on the dose of the antagonists and the disease state.

Topics: Acetylcholine; Animals; Atrasentan; Cardiovascular Agents; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelin A Receptor Antagonists; Endothelin B Receptor Antagonists; Endothelin-1; Male; Mesenteric Arteries; Microcirculation; Myography; Peptides, Cyclic; Pyrrolidines; Rats; Rats, Wistar; Receptor, Endothelin A; Receptor, Endothelin B; Up-Regulation; Vasoconstriction; Vasoconstrictor Agents; Vasodilation; Vasodilator Agents; Viper Venoms

We investigated the relationship between oxidative stress and diabetic erectile dysfunction.. A total of 23 patients with a mean +/- SD age of 56.7 +/- 5.6 years, a history of type 2 diabetes for 10.0 +/- 8.3 years and erectile dysfunction, as tested by the International Index of Erectile Function questionnaire, but without vascular and neurological complications, and 15 age matched patients with diabetes without erectile dysfunction were recruited. Circulating monocyte oxidative activity by cytofluorometry, and endothelin-1, intercellular adhesion molecule-1, plasminogen activator inhibitor-1 by enzyme linked immunosorbent assay were evaluated in all patients in the study.. Monocyte free radical production, and total and low density lipoprotein cholesterol were higher in patients with than in those without erectile dysfunction (p <0.03, <0.02 and <0.05, respectively). In all patients the International Index of Erectile Function score inversely correlated with low density lipoprotein (p <0.05), while in patients with erectile dysfunction it negatively correlated with age (p <0.03), body mass index (p <0.02), endothelin-1 (p <0.02) and intercellular adhesion molecule-1 (p <0.05). Endothelin-1, intercellular adhesion molecule-1 and plasminogen activator inhibitor-1 were not different in patients with diabetes with and without erectile dysfunction.. In men with type 2 diabetes who have erectile dysfunction but are asymptomatic for cardiovascular disease oxidative activation of monocytes is increased and it is related to other risk factors of endothelial dysfunction.

Topics: Diabetes Complications; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Erectile Dysfunction; Humans; Intercellular Adhesion Molecule-1; Male; Middle Aged; Monocytes; Plasminogen Activator Inhibitor 1; Reactive Oxygen Species

To investigate the potential role of endothelin-1 (ET-1), a potent vasoconstrictor with mitogenic properties, in the pathogenesis of proliferative diabetic retinopathy (PDR).. Plasma and vitreous samples were collected from normal patients (controls; n = 25), diabetic patients with PDR (n = 25), and diabetic patients with non-PDR (n = 25). The patients had to have epiretinal membranes (ERMs) or other ocular conditions that made them candidates for vitrectomy. Immunoreactive ET-1 (IR-ET-1) was assayed in plasma and vitreous samples by radioimmunoassay. IR-ET-1 was immunohistochemically localized in ERMs. Expression of endothelin receptors A (ETA) and B (ETB) was confirmed by reverse transcription-polymerase chain reaction analysis.. IR-ET-1 levels in plasma and vitreous samples from diabetic patients were higher (P < 0.0001) than those in samples from the control group. The levels for patients with PDR were even higher (P < 0.0001) than those for patients with non-PDR. Eyes with ERMs in the PDR group had the highest vitreous IR-ET-1 levels (14.67 +/- 0.67 pg/mL). IR-ET-1 was localized in the cellular and stromal components of ERMs in diabetic and nondiabetic patients. Furthermore, the ETA and ETB receptors were expressed in both diabetic and nondiabetic ERMs.. Diabetic patients with PDR and ERMs had the highest plasma and vitreous IR-ET-1 levels. ET-1 and its ETA and ETB receptors were present in ERMs. These data suggest that ET-1 is involved in diabetic vitreoretinal disease.

Topics: Aged; Aged, 80 and over; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Endothelin-1; Epiretinal Membrane; Female; Humans; Immunoenzyme Techniques; Male; Middle Aged; Radioimmunoassay; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Vitreous Body

This study compared lipids, the product of lipid peroxidation malondialdehyde (MDA), the acute phase reactant high-sensitive C-reactive protein (hsCRP), endothelin-1 (ET-1), P-selectin, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) between healthy controls, subjects with ischemic heart disease (IHD) and type 2 diabetes mellitus (DM) subjects who did not perform coronary artery bypass graft (CABG) surgery as well as type 2 DM subjects who performed CABG. HbA1c, lipids, MDA, hsCRP, ET-1, P-selectin, ICAM-1, and VCAM-1 levels were significantly higher in the diabetic groups than in either healthy controls or IHD subjects. In the diabetic groups, there was a negative association among hsCRP and HDL-C. ET-1, ICAM-1 levels, and TAG were positively correlated, as do the association between P-selectin, VCAM-1, and HbA1c%. Also a positive relation was found among hsCRP levels and ICAM-1, as well as MDA and ET-1. P-selectin and ICAM-1 were significantly positively correlated. This study indicates that increased level of oxidative stress marker, proinflammatory markers, and their downstream effectors adhesion molecules occur in type 2 DM.

Topics: Adult; Analysis of Variance; C-Reactive Protein; Cell Adhesion Molecules; Cholesterol, HDL; Coronary Artery Bypass; Diabetes Mellitus, Type 2; Endothelin-1; Humans; Intercellular Adhesion Molecule-1; Male; Malondialdehyde; Middle Aged; Myocardial Ischemia; P-Selectin; Triglycerides; Vascular Cell Adhesion Molecule-1

Regulation of vascular tone and blood flow involves interactions between numerous local and systemic vascular control signals, many of which are altered by Type 2 diabetes (T2D). Vascular responses to endothelin-1 (ET-1) are mediated by endothelin type A (ET(A)) and type B (ET(B)) receptors that have been implicated in cross talk with alpha(1)-adrenoceptors (alpha(1)-AR). ET(A) and ET(B) receptor expression and plasma ET-1 levels are elevated in T2D; however, whether this influences coronary alpha(1)-AR function has not been examined. Therefore, we examined the effect of ET(A) and ET(B) receptor inhibition on coronary vasoconstriction to ET-1 and alpha(1)-AR activation in a mouse model of T2D. Coronary vascular responses were examined in isolated mouse hearts from control and diet-induced T2D C57BL/6J mice. Responses to ET-1 and the selective alpha(1)-AR agonist phenylephrine (PE) were examined alone and in the presence of the nitric oxide synthase inhibitor N(omega)-nitro-l-arginine methyl ester (l-NAME) alone or in combination with selective ET(A) or ET(B) receptor inhibitors BQ-123 and BQ-788, respectively. Vasoconstriction to ET-1 was enhanced, whereas ET(B), but not ET(A), receptor blockade reduced basal coronary tone in T2D hearts. In the presence of l-NAME, ET(A) receptor inhibition attenuated ET-1 vasoconstriction in both groups, whereas ET(B) inhibition abolished this response only in control hearts. In addition, ET(A) inhibition enhanced alpha(1)-AR-mediated vasoconstriction in T2D, but not control, hearts following l-NAME treatment. Therefore, in this model, enhanced coronary ET-1 responsiveness is mediated primarily through smooth muscle ET(B) receptors, whereas the interaction with alpha(1)-ARs is mediated solely through the ET(A) receptor subtype.

Topics: Adrenergic alpha-1 Receptor Agonists; Adrenergic alpha-Agonists; Animals; Coronary Vessels; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Fats; Dose-Response Relationship, Drug; Endothelin A Receptor Antagonists; Endothelin B Receptor Antagonists; Endothelin-1; Enzyme Inhibitors; Male; Mice; Mice, Inbred C57BL; Muscle, Smooth, Vascular; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Obesity; Oligopeptides; Peptides, Cyclic; Phenylephrine; Piperidines; Receptor, Endothelin A; Receptor, Endothelin B; Receptors, Adrenergic, alpha-1; Vasoconstriction

To investigate the diagnostic efficacy and clinical application value of plasma endothelin-1 for diabetic retinopathy using receiver operating characteristic (ROC) curve analysis.. This was a prospective investigational study. Funduscopy and fundus fluorescein angiography were used as gold standards for the diagnosis of diabetic retinopathy. Plasma endothelin-1 was measured in 96 diabetic patients with retinopathy (the case group) and 144 diabetic patients without retinopathy (the control group). Enumerative data were listed in a fourfold table. The measurement data were analyzed by Student's t test and evaluated by cross-table analysis and ROC curve analysis.. (1) The plasma endothelin-1 concentration was higher in the case group than the control group (p = 0.002 < 0.01). (2) If the plasma endothelin-1 level of 162 pg/ml was adopted as the threshold for clinical diagnosis of diabetic retinopathy, the diagnostic sensitivity was 71.2%, diagnostic specificity 58% and diagnostic accuracy 66%. The positive predictive value was 69.81% and the negative predictive value 59.46%, and the positive likelihood ratio was 1.69 and the negative likelihood ratio 0.50. (3) When plasma endothelin-1 was used as a diagnostic criterion for diabetic retinopathy, the area under the ROC curve was 0.737.. Plasma endothelin-1 plays an important role in the development and progression of diabetic retinopathy. When 162 pg/ml of plasma endothelin-1 was adopted as the diagnostic threshold, the diagnostic accuracy was medium; hence, the plasma endothelin-1 level can be used as the first step for diabetic retinopathy screening.

Topics: Aged; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Endothelin-1; Female; Humans; Male; Middle Aged; Prospective Studies; ROC Curve

To investigate the relationship between syndrome differentiation of traditional Chinese medicine (TCM) and characteristic changes of vascular endothelial function in patients with diabetic arterial occlusion (DAO) of lower extremities.. Forty patients with DAO were selected as trial group. Twenty patients among them were attributed to blood stasis syndrome (group A1), and the others were attributed to syndrome of pathogenic dampness-heat attacking the lower limb (group A2) according to syndrome differentiation type of TCM. Patients with diabetes (group B), arteriosclerosis obliterans (group C) and healthy people (group D) were observed as the control groups, respectively. There were 20 cases in each group. Endothelium-dependent dilation (EDD) and endothelium-independent dilation (EID) were measured by high resolution ultrasound in the 100 subjects and the changes of vascular tension factors were also studied.. The results showed that EDD in group A was reduced significantly as compared with that in the groups B, C and D. The levels of vascular contractile factors such as endothelin-1 (ET-1) and thromboxane B2 (TXB2) in group A were higher than those in the groups B, C and D, while the levels of vascular dilatory factors such as nitric oxide (NO) and 6-keto-prostaglandin F1alpha(6-Keto-PGF1alpha) were declined significantly as compared with those in the groups B and D. Linear correlation analysis showed that EDD was correlated positively with the levels of NO and 6-Keto-PGF1alpha, while the levels of ET-1 and TXB2 had negative correlation with EDD. EDD and EID in group A2 were declined significantly as compared with those in group A1.. Our findings indicate that endothelial dysfunction may play an important role in the pathogenesis of DAO and may be associated with syndrome differentiation of TCM.

Topics: 6-Ketoprostaglandin F1 alpha; Aged; Arterial Occlusive Diseases; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diagnosis, Differential; Endothelin-1; Endothelium, Vascular; Female; Humans; Lower Extremity; Male; Medicine, Chinese Traditional; Middle Aged; Nitric Oxide; Thromboxane B2

To investigate the levels of plasma endothelin (ET)-1 and vascular endothelial growth factor (VEGT) in type 2 diabetes mellitus patients, evaluate their clinical application values in different clinical types of diabetic retinopathy (DR), and to investigate the correlation between the levels of plasma ET-1, serum VEGF and the types of DR.. Peripheral blood samples were collected from 240 patients with type 2 diabetes mellitus, 96 with retinopathy and 144 without retinopathy as controls, diagnosed by ophthalmoscopy and fundus fluorescein angiography. The level of plasma ET-1 was detected with radioimmunoassay, and the serum VEGF was measured by ELISA. Pearson correlation analysis and receiver operating characteristic (ROC) curve analysis were conducted.. The expression plasma ET-1 levels of the DM patients with mild non-proliferative retinopathy (NPDR), moderate and severe NPDR and proliferative diabetic retinopathy (PDR), were (178+/-24), (197+/-51), and (231+/-77) ng/L respectively (F=12.186, P<0.01).; and all significantly higher than that of those without DR [(155+/-26) ng/L, all P<0.01]. There was no difference in the expression of VEGF in different courses of DR [(31+/-10), (31+/-8), and (32+/-10) ng/L respectively, F=1.329, P>0.05]. The plasma ET-1 was positively correlated with the type of DR (r=0.504, P<0.01) and the courses of DR (r=0.291, P<0.01). There was a negative correlation between the VEGF level and the type of DR (r=-0.252, P>0.01). ROC curve analysis showed that the plasma ET-1 curve lied in the top left corner, and the curve of VEGF lied under the chance diagonal in all the three different types of DR. The under-curve area of plasma ET-1 were 0.742 at the level of mild retinopathy, 0.723 at the level of moderate and severe NPDR, and 0.857 at the level of PDR. The under-curve areas of VEGF were 0.296, 0.297, and 0.293 respectively. The cut-off points in different types of DR were 173, 197, and 180 ng/L respectively.. Plasma ET-1 is superior to VEGF in diagnosing different types of DR. The expression of VEGF in the blood may not accord with that in the retina. The pathogenetic condition of DR in type 2 diabetes mellitus is aggravated with the course of DR.

Topics: Adult; Aged; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Endothelin-1; Enzyme-Linked Immunosorbent Assay; Female; Humans; Male; Middle Aged; Predictive Value of Tests; Prospective Studies; Radioimmunoassay; ROC Curve; Vascular Endothelial Growth Factor A

Endothelin-1 (ET-1) promotes the contractile ability of fibroblasts, essential for wound closure and reconstitution of the dermis. Wound healing is impaired in type 2 diabetic patients (D). We compared the effect of ET-1 on proliferative transforming growth factor (TGFbeta(1)) expression, fibronectin and laminin release), differentiative [alpha-smooth muscle actin (alpha-SMA) expression] and inflammatory [monocyte chemo-attractant protein (MCP-1) and interleukin-6 (IL-6) expression] responses in skin fibroblasts of healthy subjects (C) and D, testing the relative role of ET(A) and ET(B) receptors in mediating these responses. ET-1 did not influence TGFbeta(1), fibronectin or laminin production. alpha-SMA was more abundant and more stimulated in D, as well as MCP-1 and IL-6 expression and release. These effects were prevented by BMS-182874, selective antagonist of ET(A), more abundant than ET(B) in both cell strains and whose expression rose more in D than C upon stimulation with ET-1. This peculiar pattern of responses to ET-1, presumably acquired during the chronic in vivo exposure to hyperglycemia along the natural history of the disease, may partially explain the increased susceptibility of D to chronic ulcerations.

Topics: Actins; Cells, Cultured; Chemokine CCL2; Dansyl Compounds; Diabetes Mellitus, Type 2; Endothelin A Receptor Antagonists; Endothelin-1; Female; Fibroblasts; Fibronectins; Humans; Interleukin-6; Laminin; Male; Middle Aged; Receptor, Endothelin A; Receptor, Endothelin B; Transforming Growth Factor beta1; Wound Healing

Endothelin-1 has been implicated in diabetic kidney injury, but there are few firm data establishing the temporal and spatial expression of kidney endothelin-1 in diabetes. We performed an immunohistochemical and histopathological analysis to determine endothelin-1 peptide expression in the kidneys of diabetic db/db mice and non-diabetic db/m controls. Diabetic mice were studied at 8 weeks, before histological damage is evident, and again at 16 weeks, when significant glomerular injury has occurred. Urinary endothelin-1 was 6.2- and 3.6-fold higher in 8- and 16-week diabetic mice compared to age-matched controls (P<0.01 db/db vs. db/m). Compared to non-diabetic kidneys, immunoreactive endothelin-1 was first elevated 2.5-fold (P=0.02) in the tubulointerstitial compartment at 8-week and remained high (3.8-fold, P<0.01) at 16 weeks. In contrast, glomerular endothelin-1 was elevated 3.2-fold (P=0.03) only in 16-week diabetic mice. Glomerular and tubulointerstitial endothelin-1 were unchanged in 8- and 16-week non-diabetic mice. Elevated endothelin-1 in diabetic mice associated temporally and spatially with collagen deposition, especially in the tubulointerstitial compartment. The localization of kidney endothelin-1 is consistent with a role for this peptide in renal fibrogenesis. These results also highlight the potential role of ET-1 in the pathogenesis of early tubulointerstitial changes in diabetes.

Topics: Animals; Collagen; Diabetes Mellitus, Type 2; Disease Models, Animal; Endothelin-1; Kidney; Kidney Glomerulus; Kidney Tubules; Male; Mice

We examined whether there is a differential effect of endothelin-A antagonism on coronary artery compliance in type 2 diabetes mellitus compared to non-diabetic patients.. We examined 32 patients, 11 type 2 diabetes mellitus and 21 non-diabetic patients, with atherosclerotic epicardial arteries free of significant luminal stenoses. Intracoronary BQ-123 (6 micromol), an endothelin-A receptor antagonist, was infused over 20 min. The artery lumen area in the proximal arterial segment was measured at end diastole and end systole before and after BQ-123 administration using an intravascular ultrasound catheter. Calculations were made of normalized arterial compliance index, in mm Hg(-1) x 10(3) and of arterial stiffness index beta.. Pulse pressure and heart rate did not change after BQ-123. In type 2 diabetes mellitus, normalized compliance index decreased from 1.79+/-1.36 at baseline to 1.29+/-0.82 after BQ-123 administration, whereas in non-diabetic patients it increased from 2.10+/-1.36 to 3.00+/-2.07 (p<0.05 versus baseline) (F=6.39, p=0.02). In type 2 diabetes mellitus, beta index increased from 1.97+/-0.53 to 2.46+/-0.95, whereas in non-diabetic patients it decreased from 1.83+/-0.95 to 1.63+/-0.84 (F=7.80, p=0.009). Big endothelin-1 at baseline was correlated with the baseline beta index (p<0.0001, r=0.68).. Big endothelin-1 is correlated with the coronary artery stiffness. The effect of endogenous endothelin-1 on coronary artery stiffness is impaired in type 2 diabetes mellitus. This may have important therapeutic implications with respect to the introduction of endothelin receptor antagonists as cardiovascular therapeutic agents.

Topics: Aged; Aldosterone; Compliance; Coronary Vessels; Diabetes Mellitus, Type 2; Endothelin Receptor Antagonists; Endothelin-1; Female; Humans; Male; Middle Aged; Peptides, Cyclic; Pericardium; Prospective Studies; Pulsatile Flow; Renin; Ultrasonography, Interventional

We investigated whether benidipine, a long-acting calcium channel blocker (CCB), can normalize cardiac expression profiles of the endothelin (ET)-1 system in insulin-resistant diabetes. Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model of human Type 2 diabetes, were treated for 12 wk with vehicle or benidipine (3 mg.kg(-1).day(-1)). OLETF rats exhibited a significant increase in ET-1 in plasma and left ventricular (LV) tissues compared with nondiabetic controls. Expression of prepro-ET-1, ET-converting enzyme, and ET(A) and ET(B) receptors in LV tissues was also significantly higher in OLETF rats. The two MAPKs, JNK and p38MAPK, both of which are activated by ET-1, were more abundantly expressed in OLETF rat LV tissues. All these alterations were reversed to nondiabetic levels when OLETF rats were treated with the subdepressor dose of benidipine. Furthermore, benidipine therapy resulted in hindering cardiomyocyte hypertrophy and cardiac perivascular fibrosis in OLETF rats. The beneficial actions of benidipine at the subdepressor dose on cardiac remodeling in insulin-resistant diabetes may involve normalization of the upregulated ET-1 system.

Topics: Animals; Calcium Channel Blockers; Diabetes Mellitus, Type 2; Dihydropyridines; Dose-Response Relationship, Drug; Endothelin-1; Male; Rats; Up-Regulation; Ventricular Dysfunction, Left; Ventricular Remodeling

Diabetic nephropathy is the leading cause of end-stage renal disease. Dopamine receptors are involved in the regulation of renal hemodynamics and may play a role in diabetes-induced hyperfiltration. To test this hypothesis, we investigated the renal effect of a dopamine D3 receptor antagonist (D3-RA) in hypertensive type II diabetic SHR/N-cp rats. Lean and obese SHR/N-cp rats were randomly assigned to D3-RA, angiotensin-converting enzyme inhibitor (ACE-i), or D3-RA+ACE-i treatment or control conditions. Treated animals were given the D3-RA A-437203 (10 mg/kg/body weight (BW)/day) or the ACE-i trandolapril (0.3 mg/kg BW/day) or a combination of both. At 6 months following perfusion, fixed kidneys were analyzed by morphological and stereological methods. Indices of renal damage (glomerulosclerosis, glomerulosclerosis damage index (GSI), tubulointerstitial and vascular damage), glomerular geometry and functional variables such as urinary albumin excretion, glomerular filtration rate, blood pressure, blood chemistry and BW were determined. The GSI (score 0-4) was significantly higher (P<0.05) in untreated diabetic animals (1.62+/-0.3) compared to nondiabetic controls (0.4+/-0.2) and the treatment groups (D3-RA: 0.31+/-0.12; ACE-i: 0.29+/-0.1; combination treatment: 0.12+/-0.01). Urinary albumin excretion (mg/24 h) was higher in untreated diabetic controls (102+/-19) compared to nondiabetic controls (31+/-12) and the treatment groups (D3-RA: 44+/-15; ACE-i: 41+/-13; combination treatment: 15+/-8). Mean glomerular volume was higher in untreated diabetic animals compared to nondiabetic controls and to the treatment groups. Desmin expression, a marker of podocyte damage, was elevated in untreated diabetic controls and diminished in all treatment groups. These data suggest that in a model of type II diabetes, the dopamine D3-RA had a beneficial effect on renal morphology and albuminuria, which was comparable in magnitude to that of ACE-i treatment.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dopamine Antagonists; Drug Therapy, Combination; Endothelin-1; Gene Expression; Kidney; Kidney Diseases; Kidney Function Tests; Kidney Glomerulus; Male; Rats; Rats, Inbred SHR; Receptors, Dopamine D3; RNA, Messenger; Transforming Growth Factor beta

Hyperglycemia-induced changes in vascular wall structure contribute to the pathogenesis of diabetic microvascular and macrovascular complications. Matrix metalloproteinases (MMP), a family of proteolytic enzymes that degrade extracellular matrix (ECM) proteins, are essential for vascular remodeling. We have shown that endothelin-1 (ET-1) mediates increased MMP activity and associated vascular remodeling in Type 2 diabetes. However, the effect of Type 2 diabetes and/or ET-1 on the regulation of ECM and MMP gene expression in different vascular beds remains unknown.. Aorta and mesenteric artery samples were isolated from control, Type 2 diabetic Goto-Kakizaki (GK) rats and GK rats treated with ETA antagonist ABT-627. Gene expression profile of MMP-2, MMP-9, MT1-MMP, fibronectin, procollagen type 1, c-fos and c-jun, were determined by quantitative real-time (qRT) PCR. In addition, aortic gene expression profile was evaluated by an ECM & Adhesion Molecules pathway specific microarray approach.. Analysis of the qRT-PCR data demonstrated a significant increase in mRNA levels of MMPs and ECM proteins as compared to control animals after 6 weeks of mild diabetes. Furthermore, these changes were comparable in aorta and mesentery samples. In contrast, treatment with ETA antagonist prevented diabetes-induced changes in expression of MMPs and procollagen type 1 in mesenteric arteries but not in aorta. Microarray analysis provided evidence that 27 extracellular matrix genes were differentially regulated in diabetes. Further qRT-PCR with selected 7 genes confirmed the microarray data.. These results suggest that the expression of both matrix scaffold protein and matrix degrading MMP genes are altered in macro and microvascular beds in Type 2 diabetes. ETA antagonism restores the changes in gene expression in the mesenteric bed but not in aorta suggesting that ET-1 differentially regulates microvascular gene expression in Type 2 diabetes.

Topics: Animals; Aorta; Atrasentan; Blood Vessels; Diabetes Mellitus, Type 2; Endothelin Receptor Antagonists; Endothelin-1; Gene Expression Profiling; Gene Expression Regulation; Hyperglycemia; Male; Matrix Metalloproteinases; Mesenteric Arteries; Oligonucleotide Array Sequence Analysis; Polymerase Chain Reaction; Pyrrolidines; Rats; Rats, Wistar; Reference Values

Vascular dysfunction characterized by a hyperreactivity to vasoconstrictors and/or impaired vascular relaxation contributes to increased incidence of cardiovascular disease in diabetes. Endothelin (ET)-1, a potent vasoconstrictor, is chronically elevated in diabetes. However, the role of ET-1 in resistance versus larger vessel function in mild diabetes remains unknown. Accordingly, this study investigated vascular function of third-order mesenteric arteries and basilar arteries in control Wistar and Goto-Kakizaki (GK) rats, a model of mild Type 2 diabetes. Six weeks after the onset of diabetes, contractile responses to 0.1-100 nM ET-1 and relaxation responses to 1 nM-10 microM acetylcholine (ACh) in vessels preconstricted (baseline + 60%) with serotonin (5-HT) were assessed by myograph studies in the presence or absence of a nitric oxide synthase (NOS) inhibitor, N-nitro-L-arginine (L-NNA). Maximum contractile response to ET-1 was augmented in mesenteric vessels (155 +/- 18% in GK vs. 81 +/- 6% in control; n = 5-7) but not in the basilar artery (134 +/- 29% in GK vs. 107 +/- 17% in control; n = 4 per group). However, vascular relaxation was impaired in the basilar arteries (22 +/- 4% in GK vs. 53 +/- 7% in control; n = 4 per group) but not in mesenteric arteries of GK rats. Inhibition of NOS decreased the relaxation response of basilar arteries to 15 +/- 8% and 42 +/- 5% in GK and control rats, respectively; whereas, in resistance vessels, corresponding values were 56 +/- 7% and 89 +/- 3% (vs. 109 +/- 2% and 112 +/- 3% without NOS blockade), indicating the involvement of different vasorelaxation-promoting pathways in these vascular beds. These findings provide evidence that the ET system is activated even under mild hyperglycemia and that it contributes to the hyperreactivity of resistance vessels, therefore, the ET system may play an important role in elevated blood pressure in Type 2 diabetes.

Topics: Acetylcholine; Animals; Basilar Artery; Diabetes Mellitus, Type 2; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelin-1; Endothelium, Vascular; Enzyme Inhibitors; Isometric Contraction; Male; Mesenteric Arteries; Muscle Contraction; NG-Nitroarginine Methyl Ester; Rats; Rats, Inbred Strains; Rats, Wistar; Serotonin; Vasoconstrictor Agents; Vasodilator Agents

There is increasing evidence that endogenous sex hormones regulate vascular reactivity, and testosterone may contribute to the worse prognosis for renal disease in men. Male Zucker diabetic rats exhibit improved renal hemodynamic responses after castration. It is, however, unclear whether endogenous testosterone affects renal and systemic microcirculatory responses in the female sex, especially in type 2 diabetes.. To test the hypothesis that endogenous testosterone in the female Zucker diabetic rat exerts a pathophysiologically relevant modulation of endothelial and renal microvascular function.. Female Zucker diabetic rats (FZDR) aged 5-6 weeks and from the same litter were divided into 2 groups (n = 6-8 each). The experimental group received the androgen receptor blocker flutamide, dissolved in alcohol and added to their drinking water (500 mL) at 20 mg/rat/week. The control FZDR received only the alcohol vehicle added to the same volume of drinking water. Both FZDR groups were treated for 3 months before undergoing the hemodynamic studies. A sex comparison control group of male Zucker diabetic rats (MZDR), also aged 5-6 weeks, was studied, following same protocol. Mean arterial pressure (MAP) and renal cortical blood flow (RCF) response to phenylephrine, acetylcholine, TXA2-mimetic U46619, endothelin-1 (ET-1), angiotensin II, and L-NG-nitro arginine methyl ester were studied. Furthermore, the role of protein kinase C in the responses was assessed using phorbol-12,13 dibutyrate 10(-4) M. The impact of flutamide on body weights and blood glucose of the rats were also determined.. Flutamide-treated FZDR had a significant reduction in body weight/adiposity to 432 +/- 44 g, compared to controls at 553 +/- 37 g (P = 0.045), and random blood glucose concentration of 185 +/- 44 g/dL, compared to the control FZDR at 475 +/- 34 g/dL (P = 0.002). Vehicle-treated FZDR (n = 6-8), exhibited little or no systemic or renal response to any of the agonists. By contrast, flutamide treatment of FZDR (n = 5-7) caused a normalization of the dose-dependent MAP and RCF pressor response to phenylephrine [P < 0.005, analysis of variance (ANOVA)] and the vasodilator response to acetylcholine (P <. 0.01, ANOVA). Flutamide-treated FZDR showed enhanced pressor response to U46619 (P = 0.024, ANOVA), ET-1, and angiotensin II (P < 0.03, ANOVA). Surprisingly, the augmented systemic pressor action of U46619 and ET-1 was accompanied by a renal vasodilator action, with paradoxic RCF increases to U46619 (P < 0.003, ANOVA) and to ET-1 (P < 0.001, ANOVA) only in flutamide-treated FZDR. By contrast, flutamide-treated MZDR exhibited no significant change in body weight and an attenuation of the vasoconstrictor responses and enhanced nitric oxide-mediated dilatation compared with male controls. However, no specific effect on ET-1 or TXA2 receptor-mediated renal perfusion was discernible. Both L-NG-nitro arginine methyl ester and the protein kinase C agonist phorbol-12,13 dibutyrate [10(-4)M] significantly increased MAP and reduced RCF (P < 0.03) in the experimental FZDR compared with their controls.. Flutamide administration to FZDR resulted in the reversal of abnormal systemic and renal alpha-1-mediated vasoconstriction and enhanced nitric oxide-mediated vasodilation. Flutamide caused a paradoxic but specific increase in renal perfusion during ET-1 and TXA2 receptor activation, which could be renoprotective in females. The salutary effects of flutamide on vascular reactivity in the FZDR may be mediated by a protein kinase C-dependent mechanism. These results are compatible with the notion that endogenous testosterone may regulate systemic and renal microcirculation in the female sex and in the type 2 diabetic state.

Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Female; Flutamide; Rats; Rats, Zucker; Receptors, Thromboxane A2, Prostaglandin H2; Renal Circulation; Testosterone

The risk of cerebrovascular disease is four- to sixfold higher in patients with diabetes. Vascular remodeling, characterized by extracellular matrix deposition and an increased media-to-lumen ratio, occurs in diabetes and contributes to the development of complications. However, diabetes-induced changes in the cerebrovascular structure remain unknown. Endothelin-1 (ET-1), a potent vasoconstrictor with profibrotic properties, is chronically elevated in diabetes. To determine diabetes-mediated changes in the cerebrovasculature and the role of ET-1 in this process, type 2 diabetic Goto-Kakizaki (GK) rats were administered an ET(A) receptor antagonist for 4 weeks. Middle cerebral arteries were harvested and studies were performed to determine vascular structure. Tissue and plasma ET-1 levels were increased in GK rats compared with controls. Significant medial hypertrophy and collagen deposition resulted in an increased wall-to-lumen ratio in diabetic rats that was reduced by ET(A) receptor antagonism. Vascular matrix metalloproteinase (MMP)-2 activity was higher, but MMP-1 levels were significantly reduced in GK rats, and MMP levels were restored to control levels by ET(A) receptor antagonism. We conclude that ET-1 promotes cerebrovascular remodeling in type 2 diabetes through differential regulation of MMPs. Augmented cerebrovascular remodeling may contribute to an increased risk of stroke in diabetes, and ET(A) receptor antagonism may offer a novel therapeutic target.

Topics: Animals; Atrasentan; Blood Glucose; Cerebral Arteries; Collagen; Diabetes Mellitus, Type 2; Endothelin A Receptor Antagonists; Endothelin-1; Gene Expression Regulation; Matrix Metalloproteinases; Neovascularization, Physiologic; Pyrrolidines; Rats; Telencephalon

In patients on chronic hemodialysis the prevalence of atherosclerosis is increased and is by far the leading cause of morbidity and mortality. Endothelin-1, an endothelium-derived peptide with vasoconstrictive and mitogenic effects on vascular smooth muscles, is involved in the pathogenesis of atherosclerosis. The aim of the present study was to investigate the time course of plasma endothelin-1 levels during a hemodialysis session and to explore the influence of preexisting type 2 diabetes mellitus. Forty-five clinically stable hemodialysis patients (21 females, 24 males; mean age 62 +/- 12 years) were evaluated. Patients with type 2 diabetes (n= 11) were compared with the group of patients without diabetes (n=34). Relative blood volume (BV) changes (hemoglobinometry) and blood pressure (BP) was measured. Samples were taken before, every hour during, and after hemodialysis. Plasma endothelin-1 levels were measured by enzyme-linked immunoassay (ELISA) and results were corrected according to hemoconcentration. Hemodialysis with an ultrafiltration of 2215 +/- 952 mL was performed. Total BV at the end of hemodialysis was 89.3% +/- 8.3% of the pretreatment volume. Plasma endothelin-1 was enhanced in hemodialysis patients compared to normal subjects and increased from 1.28 +/- 0.47 before to 1.44 +/- 0.54 pg/mL (ref. 0.3-0.9) at the end of hemodialysis (p<0.05). The BV change (r=0.41) and the BP (mean BP: r=0.34) correlated with plasma endothelin-1 at the end of hemodialysis (p<0.05). The levels of endothelin-1 were significantly higher in the group of dialysis patients with type 2 diabetes compared to nondiabetics in all measurements (p<0.05). These findings suggest a potential role of endothelin-1 in the pathogenesis of vascular dysfunction in diabetes mellitus. The dialysis procedure per se, through vasoconstriction due to BV decrease, local endothelial injury (a.v. fistula), or bioincompatibility reactions (foreign surface contact) may additionally alter endothelial cell functions.

Topics: Aged; Biomarkers; Case-Control Studies; Diabetes Mellitus, Type 2; Endothelin-1; Enzyme-Linked Immunosorbent Assay; Female; Follow-Up Studies; Humans; Kidney Failure, Chronic; Kidney Function Tests; Male; Middle Aged; Probability; Reference Values; Renal Dialysis; Risk Assessment; Sensitivity and Specificity; Severity of Illness Index; Treatment Outcome

The diabetic heart shows increased fibrosis, which impairs cardiac function. Endothelin (ET)-1 and nuclear factor-kappaB (NF-kappaB) interactively regulate fibroblast growth. We have recently demonstrated that Punica granatum flower (PGF), a Unani anti-diabetic medicine, is a dual activator of peroxisome proliferator-activated receptor (PPAR)-alpha and -gamma, and improves hyperglycemia, hyperlipidemia, and fatty heart in Zucker diabetic fatty (ZDF) rat, a genetic animal model of type 2 diabetes and obesity. Here, we demonstrated that six-week treatment with PGF extract (500 mg/kg, p.o.) in Zucker diabetic fatty rats reduced the ratios of van Gieson-stained interstitial collagen deposit area to total left ventricular area and perivascular collagen deposit areas to coronary artery media area in the heart. This was accompanied by suppression of overexpressed cardiac fibronectin and collagen I and III mRNAs. Punica granatum flower extract reduced the up-regulated cardiac mRNA expression of ET-1, ETA, inhibitor-kappaBbeta and c-jun, and normalized the down-regulated mRNA expression of inhibitor-kappaBalpha in Zucker diabetic fatty rats. In vitro, Punica granatum flower extract and its components oleanolic acid, ursolic acid, and gallic acid inhibited lipopolysaccharide-induced NF-kappaB activation in macrophages. Our findings indicate that Punica granatum flower extract diminishes cardiac fibrosis in Zucker diabetic fatty rats, at least in part, by modulating cardiac ET-1 and NF-kappaB signaling.

Topics: Animals; Body Weight; Cell Line; Diabetes Mellitus, Type 2; Endothelin-1; Fibrosis; Flowers; Gene Expression Profiling; Gene Expression Regulation; Heart; Lythraceae; Male; Mice; Myocardium; NF-kappa B; Obesity; Organ Size; Plant Extracts; Rats; Rats, Zucker

This study was designed to examine the association between adiponectin and C-reactive protein (CRP), interleukin-6 (IL-6) and endothelin-1, (ET-1) and their possible role in prediction of type-2 diabetes and development of diabetes and macrovascular complications. Forty subjects were studied. They were classified into four equal groups: Control, newly diagnosed type-2 diabetes, diabetics with old myocardial infarction (OMI) and acute myocardial infarction (AMI) groups. They were matched for body mass index (BMI), age, and sex. Adiponectin and IL-6 were determined by ELISA technique, CRP was determined by immunonephlometry and ET-1 was determined by radioimmunoassay. Adiponectin was found to be decreased in newly diagnosed diabetics (6.64 +/- 2.3 microg/ml), OMI (4.7 +/- 1.05 microg/ml) and AMI (4.23 +/- 0.73 microg/ml) when compared to controls (9.81 +/- 2.2 microg/ml), whereas CRP, IL- 6 and ET-1 were significantly elevated in AMI (18.6 +/- 5.3 mg/l, 12.6 +/- 4.2 pg/ml and 36.8 +/- 10.4 fmol/ml, respectively). The changes were marked in AMI group compared to other diabetic groups. Only adiponectin significantly decreased in newly diagnosed type-2 diabetics, but CRP, IL-6 and ET-1 did not significantly altered in newly diagnosed diabetics (4.9 +/- 1.6 mg/l, 6.9 +/- 2.3 pg/ml and 22.1 +/- 8.6 fmol/ml, respectively) compared to control. Adiponectin correlated negatively with CRP, IL-6 and ET-1, BMI and HbA1c, whereas inflammatory and vascular markers correlated positively with each other and with BMI and HbA1c. In conclusions, adiponectin may be implicated in the development of type-2 diabetes and macrovascular complications and can be used as an early predictor of type-2 diabetes. Whereas, none of the inflammatory and vascular markers can predict diabetes, but can be used as markers of acute vascular events and in follow up of these cases. Immunomodulation of adiponectin may help prevention and treatment of type-2 diabetes and its complications.

Topics: Adiponectin; Biomarkers; C-Reactive Protein; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Female; Humans; Interleukin-2; Male; Middle Aged

Type-2 diabetes is characterized by endotheliopathy, which increases target organ damage and mortality. There is excessive endothelin-1 and TXA(2) production, and abnormal vascular reactivity to endothelin-1, manifested as a paradoxical hypotensive action in Zucker diabetic, but not lean rats. We examined the hypothesis that there is an alteration in the ET-A/ET-B receptor subtype sensitivity, and/or the interaction or cross-talk between ET-1 and TXA(2) in type-2 diabetes, using Zucker diabetic rats and their lean littermates.. Hemodynamic studies were performed in lean and Zucker fatty diabetic rats of both sexes. Laser doppler flowmetry was used to measure renal cortical (RCF) and medullary blood flow (MBF) responses. Dose response curves for mean arterial blood pressure (MAP), MBF and RCF in response to ET-1, U46619, acetylcholine, and L-NAME (25mg/kg) were constructed after pre-treatment of the rats with either BQ610 1mg/kg i.v. or BQ788 0.5mg/kg i.v. The effects of BQ610 and BQ788 on whole blood impedance aggregation were also assessed.. BQ788, but not BQ610 abolished both the paradoxical hypotensive action of ET-1 in Zucker diabetic rats (n=7 each, P<0.001 ANOVA) as well as the dose-dependent rise in MBF (P<0.001 ANOVA). BQ788, but not BQ610 abolished the difference in response to ET-1 between lean and diabetic Zucker rats. U46619 caused a hypotensive action in male Zucker rats which was abolished by L-NAME 25mg/kg or indomethacin 10mg/kg i.v. The U46619 interaction with BQ788 on both MAP and MBF was significantly (P<0.03 ANOVA) different between lean and diabetic Zucker rats. BQ788, but not BQ610 attenuated both the MAP and MBF responses to acetylcholine or L-NAME P<0.02 ANOVA). However, BQ610 dose-dependently attenuated the slope of platelet aggregation in both lean and Zucker diabetic rats (P<0.02 ANOVA).. ET-B receptor antagonism abolished the abnormal vascular reactivity and MBF responses to ET-1, and also normalized the vasoactive responses to the level seen in healthy lean Zucker rats. ET-1 receptor blockade influences the responses to TXA(2) receptor activation. In the systemic and renal circulation, this interaction appears to be mostly ET-B receptor mediated, whilst in platelets, ET-A receptor role may be predominant. The interaction or cross-talk between ET-1 and TXA(2) is altered in the type-2 diabetic state. Collectively, these pathophysiological changes may contribute to the vicious circle of diabetic endotheliopathy.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Acetylcholine; Animals; Antihypertensive Agents; Blood Flow Velocity; Blood Pressure; Diabetes Mellitus, Type 2; Drug Interactions; Endothelin A Receptor Antagonists; Endothelin B Receptor Antagonists; Endothelin-1; Enzyme Inhibitors; Hypertension; Kidney Cortex; Kidney Medulla; Male; NG-Nitroarginine Methyl Ester; Oligopeptides; Piperidines; Platelet Aggregation; Rats; Rats, Sprague-Dawley; Rats, Zucker; Receptor Cross-Talk; Receptor, Endothelin A; Receptor, Endothelin B; Receptors, Endothelin; Thromboxane A2

Male Zucker diabetic rats exhibit a more severe endotheliopathy in comparison with their female diabetic litter mates. The plasma concentrations of both thromboxanes and endothelins are elevated in diabetes, and the receptor cross-talk between TXA(2) and ET-1 receptors may be enhanced in type-2 diabetic Zucker rats.. To determine the role of the endogenous sex steroid hormones, testosterone and estradiol on the systemic and renal microvascular reactivity to ET-1, thromboxane-mimetic U46619, ET-TXA(2) receptor interaction, and the nitric oxide vasodilator system in Zucker hypertensive-diabetic rats.. Male and female Zucker rats aged 8-10 weeks were each divided into two groups. The male rats were castrated or underwent a sham operation. The female rats were spayed (bilateral ovariectomy and hysterectomy) or had a sham operation. All rats were studied 4-6 weeks after the gonadectomy or sham operations. Blood glucose and insulin as well as plasma concentrations of testosterone and estradiol were determined. Haemodynamic studies were undertaken with determination of the dose-response curve for mean arterial pressure (MAP), renal cortical flow (RCF) and renal medullary blood flow (MBF) in response to ET-1 and U46619, and the effect of interdiction of the ET-TXA(2) interaction with ET-antagonists BQ610 and BQ788. The role of endogenous NO was assessed by its response to graded acetylcholine doses and to a L-NG-nitro-arginine methyl ester (L-NAME) infusion.. Castrated male rats had a significantly lower blood glucose concentration (295 +/- 33 mg dL(-1)) compared with their sham-controls (481 +/- 40 mg dL(-1)), P = 0.008. Mean arterial pressure tended to be lower in the castrated rats. Gonadectomy reduced the plasma testosterone and estradiol concentrations. Castration abolished the hypotensive action of U46619 compared with sham-operated male rats (P < 0.0001, anova). Conversely, the pressor action of U46619 seen in the sham-operated female rats was reversed to a profound hypotensive action in the spayed rats (P < 0.001, anova). The change in MAP after U46619 was inversely correlated to the plasma testosterone concentration (r = -0.73, P = 0.027). The paradoxical hypotensive response elicited by ET-1 in the Zucker diabetic rats of both sexes was abolished by castration only (P < 0.005, anova). Castration caused a significant (P = 0.011) augmentation of the vasodilator response to acetylcholine, while spaying caused a slight attenuation. Castration, but not spaying, resulted in significant increases in MBF after U46619 (P = 0.003, anova), ET-1 (P = 0.005, anova) and acetylcholine (P = 0.053, anova). The ET-(B) antagonist BQ788 augmented the U46619-induced rise in MAP in castrated male rats, and also abolished the U46619-induced increase in MBF (P < 0.01 anova). L-NAME (25 mg kg(-1)) increased MAP and decreased MBF in the gonadectomized and sham-operated rats, except for the castrated male Zucker rats, where it significantly increased MBF (+90 +/- 31 PU) (P = 0.0004, anova) despite the increase in MAP.. Testosterone and estradiol regulate systemic and microvascular reactivity to TXA(2) receptor stimulation in type-2 diabetic Zucker rats. The impact of testosterone on blood glucose concentration, blood pressure, and the systemic and renal microcirculatory response to ET-1 and NO, as well as the endothelin-thromboxane receptor cross talk, is greater, and opposite to that of estradiol. The effects of testosterone withdrawal may at least in part be mediated by the ET-B receptor subtype and NO generation. Androgen blockade should be investigated further for the reversal or delay of hypertensive-diabetic endotheliopathy.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Animals; Blood Glucose; Castration; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Estradiol; Female; Gonadal Steroid Hormones; Male; Microcirculation; Nitric Oxide; Ovariectomy; Rats; Rats, Zucker; Receptors, Thromboxane A2, Prostaglandin H2; Renal Circulation; Testosterone; Vasoconstrictor Agents

To study the change of vascular tension factors (VTF), including vascular contractile factors as endothelin-1 (ET-1), thromboxane A2 (TXA2) and vascular dilatory factors as nitric oxide (NO), prostacyclin (PGI2), in different stage of peripheral diabetic arterial occlusion (PDAO), and to preliminarily explore the clinical significance of these changes.. VTF in 40 diabetic patients, 15 of 2nd stage and 25 of 3rd stage, were observed by measuring level of ET-1, NO, TXB2 and 6-keto-PGF1alpha in blood plasma with RIA assay.. (1) ET-1 and TXB2 levels in all patients were higher than those in control (P < 0.05 and P < 0.01), those in patients of 3rd stage was higher than those of 2nd stage, showing significant difference (P < 0.05). (2) NO and 6-keto-PGF1alpha levels in all patients was lower than those in control, but showed no significant difference between patients of various stages (P > 0.05).. There are changes of VTF in patients with PDAO, manifesting as increase of vascular contractive factors and decrease of vascular dilative factor. The changes are diffrent in various stages, the vascular contractive and thrombotic factors in patients of 3rd stage are higher than those in patients of 2nd stage, but the injury on vascular dilative factors in the two stages showed insignificant difference.

Topics: 6-Ketoprostaglandin F1 alpha; Aged; Aged, 80 and over; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Endothelin-1; Epoprostenol; Female; Humans; Lower Extremity; Male; Middle Aged; Nitric Oxide; Thromboxane A2; Thromboxane B2; Vasomotor System

We have investigated the protective effect of YM598, a selective endothelin type A receptor antagonist, against an endothelin-1-induced proliferation of rat mesangial cells and renal function in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an animal model of type II diabetes. YM598, but not K-8794, a selective endothelin type B receptor antagonist, inhibited the endothelin-1-induced proliferation of cultured mesangial cells derived from intact Wistar rats in a concentration-dependent manner. YM598 (0.1 or 1 mg/kg), enalapril (5 mg/kg), an angiotensin- converting enzyme inhibitor, or vehicle was administered once daily by gastric gavage to 22-week-old male OLETF rats for 32 weeks. YM598 blunted the development of albuminuria in a dose-dependent manner. A higher dose of YM598 reduced albuminuria comparable with enalapril. Urinary endothelin-1 excretion was greater in the diabetic rats than in the control rats, and was not substantially influenced by the agents. Enalapril, but not YM598, mildly lowered the blood pressure in the diabetic rats, indicating that blood pressure reduction is not involved in the major mechanism of the renoprotective effect of YM598 in OLETF rats. These data suggest that endothelin is involved in the progression of diabetic nephropathy in OLETF rats, and an endothelin type A antagonist is promising for the treatment of diabetic nephropathy.

Topics: Administration, Oral; Albuminuria; Angiotensin-Converting Enzyme Inhibitors; Animals; Cell Proliferation; Cells, Cultured; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Disease Progression; Dose-Response Relationship, Drug; Enalapril; Endothelin A Receptor Antagonists; Endothelin-1; Hyperplasia; Male; Mesangial Cells; Pyrimidines; Rats; Rats, Inbred OLETF; Rats, Wistar; Receptor, Endothelin A; Sulfonamides

Cardiovascular complications are the central feature of type 2 diabetes mellitus, and insulin resistance is an early clinical manifestation of type 2 diabetes mellitus. Calcium channel blockers are widely used to treat cardiovascular diseases in diabetic patients; however, it remains unknown how endothelin-1 (ET-1) is altered and associated with cardiac lesions at the insulin-resistant early stage of type 2 diabetes mellitus, and, if so, whether calcium channel blockers can reverse such alterations. We examined plasma and cardiac expression of ET-1 in male Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a spontaneous model of human type 2 diabetes mellitus. At 8 weeks of age, OLETF rats were treated for 12 weeks with a long acting calcium channel blocker, benidipine (3 mg/kg per day p.o.) (BEN, n = 15), or with vehicle (OLETF, n = 15), and age-matched genetic control, male Long-Evans Tokushima Otsuka (LETO) rats were also used (n = 15). Blood pressure was significantly higher in OLETF than LETO rats, and benidipine treatment of OLETF rats for 12 weeks did not reduce their blood pressure significantly. Plasma and cardiac levels of ET-1 were significantly higher in OLETF compared with LETO rats (both P < 0.01), and were reversed after benidipine treatment. Our results suggest that ET-1 plays a pivotal role in the pathogenesis of cardiac complications at the insulin-resistant stage of diabetes mellitus, and that benidipine treatment may have a beneficial effect on these complications.

Topics: Age Factors; Animals; Blood Pressure; Calcium Channel Blockers; Cardiovascular Diseases; Diabetes Complications; Diabetes Mellitus, Type 2; Dihydropyridines; Disease Models, Animal; Down-Regulation; Endothelin-1; Insulin Resistance; Male; Myocardium; Rats; Rats, Inbred OLETF; Rats, Long-Evans

We examined the hypothesis that gender differences exist in platelet and vascular reactivity in type-2 diabetes mellitus, using Zucker fatty diabetic rats of both sexes and their lean littermates. Type-2 diabetes is characterized by excessive platelet production of TXA(2), which is thrombogenic. Testosterone up-regulates platelet TXA(2) receptors and the aggregation response to thromboxane mimetics. Conversely, estrogen increases vascular nitric oxide (NO) production and inhibits platelet aggregation. Hemodynamic studies were undertaken with the determination of dose-response curve for MAP and renal cortical blood flow (RCF) in response to U46619, angiotensin-II, phenylephrine and endothelin-1, as well as the systemic hemodynamic response to acetylcholine and L-NG nitro-arginine methylester (L-NAME). Platelet aggregation response was evaluated using whole blood impedance aggregometry. There were significant gender differences in the systemic blood pressure and RCF response to TXA(2)-mimetic U46619 and angiotensin-II (P<0.02, ANOVA) but not to phenylephrine or endothelin-1. Male rats exhibited a paradoxical hypotensive response to U46619 (-18+/-11 mmHg) compared with a peak pressor response of +6+/-1 mmHg in female rats (P<0.01, ANOVA). The male rats exhibited an attenuated systemic vasodilator response (P<0.001, ANOVA) to acetylcholine (fall in MAP in male diabetic rats being -24+/-8 mmHg, compared with a fall of -50+/-8 mmHg in females), but a greater rise in the renal cortical resistance in response to NO inhibition by L-NAME (P<0.03) compared with the female rats. Both the slope (46+/-2) and the peak magnitude of the U46619-induced whole blood platelet aggregation (13+/-1) ohms were significantly higher (P<0.01, ANOVA) in male (n=10) compared with female diabetic rats (n=8) (29+/-0.8 slope, 10.0+/-0.8 ohms, respectively). Thus, the male diabetic Zucker rats exhibited an impaired response to vasoconstrictors (U46619 and angiotensin-II) and to endothelial (NO)-mediated vasodilation. The male gender may therefore be associated with the greater prothrombotic activity and a worse impairment of endothelial reactivity in the type-2 diabetic state.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Angiotensin II; Animals; Blood Pressure; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Enzyme Inhibitors; Female; Kidney Cortex; Male; NG-Nitroarginine Methyl Ester; Nitric Oxide; Phenylephrine; Platelet Aggregation; Rats; Rats, Zucker; Renal Circulation; Sex Characteristics; Vasoconstrictor Agents; Vasodilation

The pathomechanisms that cause renal damage in diabetes have not been completely clarified. Treatment with angiotensin-converting enzyme inhibitors (ACE-i) is highly effective but fails to completely prevent end-stage renal disease. The effects of ET(A)-receptor blockers (ET(A)-RB) on renal damage are controversial and have rarely been investigated in type 2 diabetes. We compared the influence of the selective ET(A)-RB LU135252 and the ACE-i Trandolapril on renal structure in the SHR/N-cp rat model of type 2 diabetes. Three-month-old male SHR/N-cp rats were left untreated or received daily either Trandolapril or LU135252. The experiment was terminated after 6 months. The glomerulosclerosis index; tubulointerstitial damage index; and glomerular geometry, glomerular cell number, and capillary density were investigated. Proliferating cell nuclear antigen and desmin expression of podocytes, renal mRNA expression of endothelin (ET-1) and transforming growth factor-beta, blood pressure, and urine albumin excretion were measured. The glomerulosclerosis index was significantly higher in untreated diabetic animals than in the groups that were treated with ACE-i and ET(A)-RB. There were analogous changes in tubulointerstitial damage index. Treatment with either substance comparably lowered urinary albumin excretion in diabetic SHR/N-cp. Podocyte and endothelial cell numbers per glomerulus decreased in untreated diabetic animals; this was prevented by the ACE-i but not by the ET(A)-RB. Glomerular capillary length density was lower in SHR/N-cp, and this was normalized by ACE-i only. Increased expression of desmin and proliferating cell nuclear antigen expression of podocytes in the SHR/N-cp was abrogated by ACE-i but not by ET(A)-RB. Treatment with ACE-i or ET(A)-receptor antagonist resulted in less structural and functional alterations, but the ET(A)-RB was inferior to the ACE-i. This is particularly the case for podocyte changes pointing to angiotensin II-dependent pathomechanisms.

Topics: Albuminuria; Angiotensin-Converting Enzyme Inhibitors; Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Endothelin Receptor Antagonists; Endothelin-1; Immunohistochemistry; Indoles; Kidney; Male; Phenylpropionates; Proliferating Cell Nuclear Antigen; Pyrimidines; Rats; RNA, Messenger; Transforming Growth Factor beta

To study the effect of the Compound of traditional Chinese drugs and Benazepril on gene expression of renal endothelin and its receptor of experimental diabetic nephropathy(DN). To discove the mechanism of the compound of traditional Chinese drugs in treating DN.. Streptozotocin DN model was built and influenced with the compound of traditional Chinese drugs and Benazepril. The changes of Upro, Glu, HbA1C and (PT-PCR) mRNA expression levels of ET-1, ETA-R of the renal cortex were tested, and thus the histopathological character of the kidney was analysed.. The compound of traditional Chinese drugs and Benazepril have significant difference from normal saline in the improvement of Upro, Glu, HbA1C. The compound of traditional Chinese drugs have significant difference from Benazepril in the improvement of Glu, HbA1C. The mRNA expression level of ET-1, ETA-R of the renal cortex of DN model was raised. After influenced by the compound of traditional Chinese drugs and Benazepril, the over-expression level de-creased (still higher than normal control ones). The compound of traditional Chinese drugs were more effective than Benazepril to inhibit the proliferation of the stalk region and the third cells.. ET takes part in the process of diabetic glo-Merulosclerosis. Both the compound of traditional Chinese drugs and Benazepril can influence the expression quantity from the level of gene transcription of ET and its receptor. The compound of traditional Chinese drugs can not only reduce urinary albumin of DN, but also improve blood glucose, glycosylated hemoglubin. And it can inhibit nonenzymatic glucosylation of protein as well as the proliferation of the stalk region and the third cells.

Topics: Animals; Benzazepines; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Drug Combinations; Drugs, Chinese Herbal; Endothelin-1; Gene Expression; Kidney Cortex; Plants, Medicinal; Random Allocation; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A; RNA, Messenger

Topics: Adult; Blood Glucose; Blood Pressure; Body Mass Index; Cholesterol; Diabetes Mellitus, Type 2; Endothelin-1; Female; Fibrinogen; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Triglycerides

To clarify the association between the actions of insulin on the vascular wall and on the muscles in diabetes, we evaluated insulin-mediated vasodilation and muscle glucose uptake simultaneously using the euglycemic hyperinsulinemic glucose clamp technique and the calculation of total peripheral vascular resistance (TPR) from arterial pulse wave analysis in 19 Japanese patients with type 2 diabetes who had no signs of atherosclerosis. During the clamp study, the plasma norepinephrine (NE) level and plasma renin activity (PRA) increased without showing any significant correlation to the glucose infusion rate (GIR); a marker of muscle insulin sensitivity, and no changes of other plasma vasoactive hormone levels were observed. TPR decreased over time during the clamp study. The decrease of TPR from baseline was 0.88 +/- 0.02 at 1 h (mean +/- S.E.M., P < 0.01) and 0.79 +/- 0.03 at 2 h (P < 0.01), and the relative change in TPR from baseline was negatively correlated with GIR (r = -0.48 at 1 and 2 h; both P < 0.05). Our results suggest that there is also insulin resistance in the vascular wall, and this phenomenon may be associated with muscle insulin resistance in type 2 diabetes.

Topics: Adult; Atrial Natriuretic Factor; Blood Glucose; Diabetes Mellitus, Type 2; Endothelin-1; Female; Glucose Clamp Technique; Humans; Infusions, Intravenous; Insulin; Insulin Resistance; Male; Muscle, Skeletal; Norepinephrine; Regression Analysis; Renin; Sodium; Vascular Resistance; Vasodilation

Plasma endothelin-1, the nitric oxide (NO) mediator intraplatelet cyclic guanosine monophosphate (cGMP), the prostacyclin mediator cyclic adenosine monophosphate (cAMP) and the macrophage derived inflammatory mediator plasma neopterin were measured in men with Type 2 diabetes mellitus (n=91), impaired glucose tolerance (IGT; n=51), previously abnormal glucose tolerance (PAGT; n=20), and 34 healthy control men. Plasma endothelin-1was higher in men with Type 2 diabetes mellitus than in controls [4.1 (1.0-14.3) vs. 2.1 (0.2-8. 7) ng/l; P<0.001). Intraplatelet cGMP was higher in men with PAGT [0. 84 (0.57-2.76) pmol/10(9) platelets; P<0.05], IGT [0.85 (0.48-3.53); P<0.001] and Type 2 diabetes mellitus [0.90 (0.47-3.86); P<0.001] than in controls [0.70 (0.42-1.70]. No differences existed between groups concerning intraplatelet cAMP or plasma neopterin. Plasma endothelin-1 correlated with fasting plasma glucose (r=0.33; P<0.001) and HbA1(c) (r=0.29; P<0.001). In conclusion, elevated plasma endothelin-1 in Type 2 diabetes mellitus and its relationship to glucose and HbA1(c) suggest a putative role for endothelin-1 in diabetic endothelial cell damage. Increased cGMP indicating enhanced production/activity of NO suggests that factors other than reduced NO activity contribute to enhanced platelet aggregation in diabetes.

Topics: Aged; Blood Glucose; Blood Platelets; Blood Pressure; Cholesterol; Cyclic GMP; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Endothelin-1; Glucose Intolerance; Glycated Hemoglobin; Humans; Leukocyte Count; Lipoproteins, HDL; Lipoproteins, LDL; Male; Middle Aged; Reference Values; Smoking; Vascular Diseases

Incubation of bovine aortic endothelial cells (BAECs) with erythrocytes from patients with type 2 diabetes induced an increase in endothelin 1 (ET-1) production. The effect of erythrocytes on ET-1 synthesis was dependent on glycemic control. ET-1 levels after incubation with erythrocytes derived from patients with HbA(1c) levels <6% were just half the levels observed after incubation with erythrocytes from patients with HbA(1c) levels >8%. Nepsilon-(carboxymethyl)lysine (CML)-containing protein isolated from patients' erythrocytes induced ET-1, and CML-containing protein-dependent ET-1 induction was blocked by the recombinant decoy peptide soluble receptor for advanced glycation end products (AGEs), which comprises the NH2-terminal Ig domain of the receptor for AGEs. In vitro-generated AGEs induced ET-1 mRNA transcription (nuclear run-on assay and Northern blot) in a time- and dose-dependent manner. Transient transfection of BAECs with a chimeric construct containing the 5' promoter region of the ET-1 gene linked to a reporter gene confirmed that AGE induced ET-1 promoter activity. Electrophoretic mobility shift assay confirmed AGE-inducible binding of members of the nuclear factor-kappab (NF-kappaB) family to a potential binding site at -2,090 bp. Binding was functionally significant because overexpression of the cytoplasmic inhibitor of NF-kappaB or deletion of the NF-kappaB binding site reduced ET-1 induction, whereas overexpression of NF-kappaB p65 induced ET-1 even in the absence of AGEs. Thus, ET-1 transcription is controlled by the AGE-inducible redox-sensitive transcription factor NF-kappaB.

Topics: Animals; Aorta; Binding Sites; Cattle; Cells, Cultured; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Erythrocytes; Gene Expression Regulation; Genes, Reporter; Glycated Hemoglobin; Glycation End Products, Advanced; Humans; In Vitro Techniques; NF-kappa B; Oligodeoxyribonucleotides, Antisense; Promoter Regions, Genetic; Recombinant Fusion Proteins; Sequence Deletion; Thionucleotides; Transcription, Genetic; Transfection

Endothelial markers endothelin 1 (ET-1) and von Willebrand factor (vWF) were assessed in patients with type 2 diabetes and dyslipidemia and in patients with hypercholesterolemia.. In this case-control study, plasma ET-and vWF levels were measured by enzyme-linked immunosorbent assay in 35 normoalbuminuric type 2 diabetic patients with dyslipidemia (56+/-5 years), in 21 nondiabetic patients with hypercholesterolemia (52+/-7 years), and in 19 healthy control subjects (45+/-4 years). All of the individuals were normotensive and nonsmokers. Urinary albumin was measured by immunoturbidimetry.. ET-1 levels were higher (P<0.0001) in type 2 diabetic dyslipidemic patients (1.62+/-0.73 pg/ml) than in both nondiabetic hypercholesterolemic patients (0.91+/-0.73 pg/ml) and control subjects (0.69+/-0.25 pg/ml). vWF levels were significantly increased (P = 0.02) in type 2 diabetic (185.49+/-72.1%) and hypercholesterolemic (163.29+/-50.7%) patients compared with control subjects (129.70+/-35.2%). In the multiple linear regression analysis. ET-1 was significantly associated (adjusted r2 = 0.42) with serum triglyceride levels (P<0.001), age (P<0.01), insulin sensitivity index (P<0.02), and albuminuria levels (P<0.04). vWF levels were associated (adjusted r2 = 0.22) with albuminuria (P<0.001), fibrinogen levels (P<0.02), and BMI (P<0.03).. Compared with hypercholesterolemic patients, type 2 diabetic patients with dyslipidemia have increased levels of ET-1 and vWF which may indicate more pronounced endothelial injury. These findings appear to be related to components of the insulin resistance syndrome.

Topics: Albuminuria; Blood Pressure; Case-Control Studies; Diabetes Mellitus, Type 2; Endothelin-1; Enzyme-Linked Immunosorbent Assay; Female; Humans; Hypercholesterolemia; Hyperlipidemias; Lipoproteins; Male; Middle Aged; Reference Values; Triglycerides; von Willebrand Factor

Genetic factors have been implicated in the development of the common aetiologies of end-stage renal disease (ESRD), including renal failure attributed to hypertension, diabetes mellitus, systemic lupus erythematosus and human immunodeficiency virus infection. Nitric oxide (NO) and endothelin are powerful vasoactive mediators involved in inflammation and regulation of vascular tone and blood pressure. We evaluated the role of the neuronal constitutive (NOS1) and endothelial constitutive (NOS3) nitric oxide synthase genes and the endothelin-1 (EDN-1) gene in predisposition to chronic renal failure in African-Americans.. The study population for the linkage and association analyses in ESRD consisted of 361 individuals from 168 multiplex African-American families. These individuals comprised 207 unweighted sibling pairs concordant for all-cause ESRD. Microsatellite markers NOS1B (NOS1), D7S636 (NOS3) and CPHD1-1/2 (EDN-1) were genotyped in the sample. In addition, a mutation, Glu298Asp, in exon 7 of NOS3 and a 27 bp variable number tandem repeat (VNTR) marker in intron 4 of NOS3 were evaluated in the sibling pairs and in an additional 92 unrelated African-Americans with type 2 diabetes mellitus-associated ESRD (singletons). Association analyses utilized the relative predispositional effect method. Model independent linkage analyses were performed using GeneHunter-plus and MapMaker/SIBS (exclusion analysis) software.. Significant evidence for association with ESRD was detected for alleles 7 and 9 of the NOS1 gene (11.9 and 34.2%, respectively, in unrelated probands of ESRD families versus 6.5 and 27.5%, respectively, in race-matched controls, both P:<0.01). These associations were maintained when the unrelated first sibling from each family was used in a case-control comparison and was most pronounced in the non-diabetic ESRD cases. The NOS3 and EDN-1 markers failed to provide consistent evidence for association in the sibling pairs and the diabetic ESRD singletons, although we identified two novel endothelial constitutive NOS4 (ecNOS4) VNTR alleles in African-Americans. Significant evidence for linkage was not detected between the NOS genes or the EDN-1 gene in either all-cause ESRD or when the ESRD sibling pairs were stratified by aetiology (type 2 diabetic ESRD or non-diabetic aetiologies).. Based upon the consistent allelic associations, we believe that further evaluation of the NOS1 gene in ESRD susceptibility in African-Americans is warranted.

Topics: Adult; Amino Acid Substitution; Base Sequence; Black or African American; Black People; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelin-1; Exons; Genetic Markers; Genetic Predisposition to Disease; Humans; Kidney Failure, Chronic; Microsatellite Repeats; Minisatellite Repeats; Molecular Sequence Data; Nitric Oxide Synthase; Nitric Oxide Synthase Type I; Nitric Oxide Synthase Type III; North Carolina; Nuclear Family

Endothelin-1 has potent vasoconstrictor and vasopressor actions contributing to basal vascular tone and maintenance of blood pressure acting predominantly through endothelin-A receptors. Endothelin antagonists may be of value in the treatment of hypertension and heart failure. However, the role of endothelin-1 in the regulation of vascular tone and the potential benefits of endothelin antagonists in non-insulin-dependent diabetes mellitus (Type II diabetes) are less clear. Vasoconstriction to exogenous endothelin-1 is impaired in Type II diabetes. The purpose of this study was to determine whether vasoconstriction to endogenous endothelin-1 acting through the endothelin-A receptor is impaired in Type II diabetes. In ten patients with Type II diabetes and nine controls the endothelin-A receptor antagonist BQ123 was infused intra-arterially at 100 nmol/min for 60 min followed by normal saline for 30 min. Forearm blood flow was measured using venous occlusion plethysmography. Control subjects showed gradual onset of vasodilation in response to BQ123 (P < 0.001). Diabetic subjects, however, showed no significant response (P > 0.05). There was a significant difference between the diabetic and control groups (P < 0.05). Blockade of the endothelin-A receptor is associated with impaired vasodilation in Type II diabetes indicating vasoconstriction to endogenous endothelin-1 mediated by the endothelin-A receptor is impaired.

Topics: Adult; Aged; Antihypertensive Agents; Diabetes Mellitus, Type 2; Endothelin Receptor Antagonists; Endothelin-1; Forearm; Humans; Male; Middle Aged; Peptides, Cyclic; Receptor, Endothelin A; Receptors, Endothelin; Regional Blood Flow; Vasoconstriction

After coronary artery bypass grafting procedures, a higher incidence of morbidity and mortality has been reported in diabetic patients. We tested whether coronary artery bypass grafting in diabetics affects the endothelin-1 and nitric oxide coronary effluent profile during reperfusion.. Twenty-one consecutive patients (9 with type II diabetes mellitus, 12 non-diabetics) underwent coronary artery bypass grafting by one surgeon. The two groups did not differ in preoperative ejection fraction, Parsonnet score, number of vessels bypassed, or cross-clamp time. Each patient was treated in the same intraoperative manner with single atrial, aortic, and antegrade and retrograde cardioplegia (CPL) cannulas. Cold CPL arrest was by antegrade and retrograde infusion of modified Buckberg CPL solution. Warm CPL solution was infused before reperfusion. Coronary sinus blood samples were obtained for estimation of endothelin-1 and nitrite plus nitrate before CPL arrest and at 1 and 15 minutes after each of 2 reperfusion periods.. In diabetics, endothelin-1 was significantly increased at all reperfusion times as compared with non-diabetics. Nitrite plus nitrate levels were significantly higher in patients with diabetes than in those without, but did not change with time in either of the groups.. Reperfusion after CPL during coronary artery bypass grafting procedure can trigger the release of endothelin-1 in patients with diabetes mellitus. This may favor increased vascular tone or positive inotropic responses after coronary artery bypass grafting and may contribute to significant cardiovascular consequences in diabetic patients.

Topics: Coronary Artery Bypass; Diabetes Mellitus, Type 2; Endothelin-1; Female; Heart Arrest, Induced; Hemodynamics; Humans; Male; Middle Aged; Nitrates; Nitric Oxide

Topics: Arterial Occlusive Diseases; Diabetes Mellitus, Type 2; Endothelin-1; Humans; Leg

Insulin stimulates endothelin-1 (ET-1) expression in a dose-response relationship, and ET-1 effects on vascular wall structure are similar to the long-term complications of diabetes. We therefore determined whether the plasma ET-1 concentration in patients with diabetes is associated with their total insulin exposure to see if plasma ET-1 might be a link between insulin exposure and long-term complications of diabetes. We studied 69 patients with Type I and 40 patients with Type II diabetes mellitus in equally tight glycaemic control for 2 years in a cross-sectional design. We measured basal and glucagon-stimulated plasma C-peptide, abdominal sagittal diameter, skinfold thickness, glomerular filtration rate, albumin excretion rate and standard clinical characteristics. Mean HbA1c was 6.4% in Type I and 6.3% in Type II diabetes. Patients with an albumin excretion rate >300 microg/min were excluded. Adjusted mean plasma ET-1 was 4.11 (S.E.M. 0.39) pg/ml in 21 normal subjects, 3.47 (0.19) pg/ml in Type I diabetes and 4.84 (0.26) pg/ml in Type II diabetes (P=0.0001). In all patients with measurable plasma C-peptide, plasma ET-1 was associated with basal plasma C-peptide (r=0.5018, P<0.0001), with stimulated plasma C-peptide (r=0.5379, P<0.0001), and with total daily insulin dose (r=0.2219, P=0.00851). Abdominal obesity, metabolic abnormalities, blood pressure and glomerular filtration rate were not associated with plasma ET-1, when corrected for C-peptide and daily insulin dose. Our study shows that the plasma concentration of ET-1 is closely associated with insulin secretion and insulin dose in patients with diabetes. Plasma ET-1 is higher in Type II diabetes than in Type I diabetes. Increased insulin exposure in patients with diabetes may have long-term effects on vascular wall structure through its stimulation of ET-1 expression.

Topics: Adult; Aged; Aged, 80 and over; C-Peptide; Cross-Sectional Studies; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Drug Administration Schedule; Endothelin-1; Female; Follow-Up Studies; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Multivariate Analysis

Endothelin-1, and constitutive endothelial nitric oxide synthase, have been implicated in the pathogenesis of diabetic retinopathy. We therefore screened polymorphisms within the genes encoding these two vasoactive agents in a sample of individuals with 15 years of diabetes and no retinopathy (ETDRS level 10 or better) and those with severe retinopathy (ETDRS level 50 or worse).. PCR primers for highly polymorphic sites within the EDN1 and NOS3 genes were used to genotype individuals with type 1 or type 2 diabetes with severe or no retinopathy. Allele frequencies were compared between groups using chi-squared analysis and adjusting for multiple comparisons.. No significant differences were observed in allele frequencies for these two markers between the patients who had retinopathy and the patients who did not.. Polymorphic variability in the EDN1 and NOS3 genes does not appear to have a major impact on determining susceptibility or resistance to diabetic retinopathy.

Topics: Adult; Alleles; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Dinucleotide Repeats; Endothelin-1; Genetic Predisposition to Disease; Humans; Nitric Oxide Synthase; Nitric Oxide Synthase Type III; Polymerase Chain Reaction; Polymorphism, Genetic

Abnormalities in vascular reactivity in the micro- and macrocirculation are well established in type 2 diabetes. However, little is known about changes in vascular reactivity in those at risk for developing type 2 diabetes. To address this situation, the vascular reactivity in both the micro- and macrocirculation was studied in four age and sex comparable groups: 30 healthy normoglycemic subjects with no history of type 2 diabetes in a first-degree relative (controls), 39 healthy normoglycemic subjects with a history of type 2 diabetes in one or both parents (relatives), 32 subjects with impaired glucose tolerance (IGT), and 42 patients with type 2 diabetes without vascular complications (diabetes). Laser Doppler perfusion imaging was used to measure vasodilation in the forearm skin in response to iontophoresis of 1% acetylcholine chloride (Ach) (endothelium-dependent) and 1% sodium nitroprusside (SNP) (endothelium-independent), whereas high-resolution ultrasound images were used to measure brachial artery diameter changes during reactive hyperemia. Plasma concentrations of endothelin-1 (ET-1), von Willebrand factor (vWF), soluble intercellular adhesion molecule (sICAM), and soluble vascular cell adhesion molecule (sVCAM) were also measured as indicators of endothelial cell activation. The vasodilatory responses to Ach, expressed as percent increase of blood flow over baseline, were reduced in relatives (98 +/- 48, mean +/- SD), IGT (94 +/- 52), and diabetes (74 +/- 45) compared with controls (126 +/- 67) (P < 0.001 controls versus relatives, IGT, and diabetes). The responses to SNP were similarly reduced: controls (123 +/- 46), relatives (85 +/- 46), IGT (83 +/- 48), and diabetes (65 +/- 31) (P < 0.001 controls versus relatives, IGT, and diabetes) as were the responses in the brachial artery diameter during reactive hyperemia: controls (13.7 +/- 6.1), relatives (10.5 +/- 6.7), IGT (9.8 +/- 4.5), and diabetes (8.4 +/- 5.0) (P < 0.01 controls versus relatives, IGT, and diabetes). Women had greater responses than men in both the micro- and macrovascular circulatory tests, but a similar progressive reduction was observed in both sexes with increasing degrees of glucose intolerance. A significant inverse correlation was found between microvascular reactivity and systolic blood pressure, fasting plasma glucose, HDL cholesterol, fasting plasma insulin, and homeostasis model assessment (HOMA) values, an index of insulin resistance. BMI and diastolic blood pressu

Topics: Acetylcholine; Adult; Aged; Biomarkers; Case-Control Studies; Cell Adhesion Molecules; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Endothelin-1; Endothelium, Vascular; Female; Humans; Iontophoresis; Male; Microcirculation; Middle Aged; Nitroprusside; Risk Factors; Skin; Solubility; Vascular Cell Adhesion Molecule-1; von Willebrand Factor

To investigate whether urinary and plasma endothelin (ET)-1 concentrations are responsive to the alteration of intravascular blood volume in uncontrolled diabetic patients, we determined urinary ET-1 excretion and plasma ET-1 concentration in 42 newly diagnosed type 2 diabetic patients and 38 normal subjects. Mean fasting plasma glucose value (12.8 +/- 0.72 mmol l-1) and plasma renin activity (PRA, 2.80 +/- 0.44 ng ml-1 hr-1) in diabetic patients were significantly higher as compared to normal controls (mean plasma glucose value: 5.2 +/- 0.83 mmol l-1; mean PRA value: 1.34 +/- 0.17 ng ml-1 hr-1), whereas plasma ET-1 value (1.33 +/- 0.07 pmol l-1) was not significantly different from that (1.29 +/- 0.06 pmol l-1) of normal controls. Mean urinary ET-1 excretion level (7.53 +/- 0.74 nmol mol-1 creatinine) was significantly higher than that (5.36 +/- 0.37 nmol mol-1 creatinine) of normal controls. Urinary ET-1 excretion was correlated with plasma glucose value (r = 0.360, p < 0.05) and PRA value (r = 0.381, p < 0.05). Urinary ET-1 excretion rate (5.17 +/- 0.37 nmol mol-1 creatinine) and PRA value (1.42 +/- 0.18 ng ml-1 hr-1) declined to normal levels when mean plasma glucose value decreased to the level of 7.1 +/- 0.39 mmol l-1 in diabetic patients after 4 months of glycemic control. Our results indicated that renal-derived ET-1 was responsive to the alteration of intravascular blood volume in untreated newly diagnosed type 2 diabetic patients.

Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Endothelin-1; Female; Humans; Male; Middle Aged; Renin

Diabetes is associated with altered vascular responses, and diabetic patients demonstrate increased morbidity and mortality after coronary artery bypass grafting (CABG). We tested whether endothelin (ET)-1 levels in this patient population differed from those in nondiabetic subjects after CABG. Of 14 consecutive patients who underwent CABG by the same surgeon, 7 had type 2 diabetes and 7 were nondiabetic. The two groups did not differ significantly in preoperative ejection fraction, number of vessels bypassed, cross-clamp time, or Parsonnet's score. Coronary sinus blood samples were obtained before cardioplegic arrest and then obtained at 1 and 15 min after each of two reperfusion periods: reperfusion A (native coronary perfusion plus the left internal mammary artery), reperfusion B (saphenous vein graft perfusion). ET-1 was significantly increased at all reperfusion time points in diabetic patients compared with nondiabetic patients. In diabetic patients, reperfusion after CABG can trigger the release of ET-1, which may be a contributing factor in the increased cardiac morbidity seen in this patient population.

Topics: Coronary Artery Bypass; Coronary Vessels; Diabetes Mellitus, Type 2; Endothelin-1; Heart Arrest, Induced; Humans; Middle Aged

To evaluate the role of circulating and renal endothelin-1 (ET-1) in early diabetic nephropathy, plasma ET-1 levels and urinary ET-1 excretion were evaluated in lean, normotensive patients affected by non-insulin-dependent diabetes (NIDDM) either with (n = 9, NIDDM+) or without microalbuminuria (n = 18, NIDDM-); in never-treated, lean, essential hypertensive patients with (n = 12, EH+) or without microalbuminuria (n = 10, EH-); and in healthy volunteers (n = 12). Results showed higher plasma ET-1 levels in NIDDM+ (1.97 +/- 0.58 pg/mL) than in NIDDM- (1.59 +/- 0.14 pg/mL, P = .013), EH+ (1.40 +/- 0.21 pg/mL, P = .005), EH- (0.91 +/- 0.19 pg/mL, P < .0001), and controls (0.60 +/- 0.10 pg/mL, P < .0001). The circulating ET-1 concentration was also higher in EH+ than EH- and controls (P < .0001). Urinary ET-1 excretion did not differ (P = .387, NS) between NIDDM+ (48.5 +/- 20.1 pg/min) and NIDDM- (40.9 +/- 21.6 pg/min), but was significantly reduced (P < .0001) in both groups compared with controls (70.0 +/- 15.5 pg/min). Similar findings were observed in hypertensive subgroups. No correlations were found between urinary ET-1 and other variables, including plasma ET-1 levels, in all groups. In conclusion, NIDDM+ is accompanied by a significant increase in plasma ET-1 levels. A significant elevation of circulating ET-1 concentration was evident also in NIDDM-, suggesting that early abnormalities of ET-1 production might precede the microalbuminuric phase of diabetes-related renal damage.

Topics: Adult; Aged; Albuminuria; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelin-1; Female; Humans; Hypertension; Male; Middle Aged

Endothelin-1 (ET-1), a vasoconstrictor and mitogenic endothelium-derived peptide, has been considered as a marker for endothelial damage and potential contributor to the development of the atherogenic process.. To evaluate the pattern of plasma ET-1 secretion in non-insulin-dependent diabetes mellitus (NIDDM) and nondiabetic patients with chronic arterial obstructive disease (CAOD) of the lower limbs, plasma levels of ET-1 were determined in 12 NIDDM patients (10 men and 2 women; mean age 63+/-8 years) with CAOD of the lower limbs at Fontaine stage II and in 12 nondiabetic patients (11 men and 1 woman; mean age 62+/-4 years) with comparable arteriopathy. Ten normal subjects comprised the control population.. The plasma levels of ET-1 in NIDDM patients with CAOD of the lower limbs were 5.7+/-0.3 pmol/L, which represented a significant (p<0.001) difference from the values in nondiabetic patients with comparable arteriopathy (4.1+/-0.6 pmol/L) and those in the control group (2.7+/-0.7 pmol/L). Plasma levels of ET-1 showed a significant (p<0.0001) positive correlation with the levels of fasting insulin in NIDDM patients with CAOD of the lower limbs. Increased plasma ET-1 could reflect a major and/or more diffuse endothelial cell damage or dysfunction in NIDDM than in nondiabetic patients with comparable CAOD of the lower limbs. Augmented mitogenic ET-1 levels could also have a role both in diabetic and nondiabetic angiopathy.. The positive correlation between ET-1 plasma levels and fasting insulin levels in NIDDM patients with CAOD of the lower limbs suggests that the increased ET-1 release could be related to the augmented insulin secretion in these patients. Insulin-related overproduction of ET-1 could promote the atherogenic process and enhance the vascular tone to a greater extent in NIDDM than in nondiabetic patients with CAOD of the lower limbs.

Topics: Arterial Occlusive Diseases; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Endothelin-1; Female; Humans; Insulin; Male; Middle Aged

To evaluate the possible effect of short- and long-term insulin treatment on arterial blood pressure (BP) and endothelin-1 (ET-1) plasma levels in type 2 diabetic patients.. Seven type 2 diabetic patients with secondary failure to oral hypoglycemic drugs (SFOH) were studied. Twenty-four-hour arterial BP monitorization (Spacelabs 90207) was performed before initiation of insulin treatment (time 0), 6 days after (time 1) and 1 year later (time 2). Moreover, ET-1 plasma levels were measured.. Insulin treatment did not produce any variation in systolic (124.3 +/- 11.6; 120.7 +/- 7.9; 127.0 +/- 13.4 mmHg) and diastolic (72.8 +/- 5.9; 71.5 +/- 3.4; 71.8 +/- 5.2 mmHg) 24-h BP monitorization at times 0, 1 and 2, respectively. The systolic and diastolic day/night differences did not change in the three times studied. Neither were significant differences observed in ET-1 plasma levels.. In patients with SFOH, insulin treatment did not induce any short- or long-term increase in BP or any variation in plasma ET-1 levels.

Topics: Aged; Albuminuria; Blood Pressure; Blood Pressure Determination; Body Constitution; Body Mass Index; Chromatography, High Pressure Liquid; Circadian Rhythm; Diabetes Mellitus, Type 2; Endothelin-1; Female; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Sodium

Peri-operative ischemic episodes following coronary artery bypass grafting with the internal mammary artery (IMA) are thought to be due to a vasospasm of this conduit. Endothelin-1 (ET-1) is a potent vasoconstrictor by itself and increases the response to other vasoconstrictor stimuli. This study focused on the possible role of an enhanced tissue ET-1-like immunoreactivity in the perioperative reaction of the IMA in patients with diabetes or hypercholesterolemia.. Specimens of the distal part of the IMA from 46 patients (mean age 58.5 years, four women, 42 men) were studied prospectively. Nine of those patients were diabetic and 26 had evidence of hypercholesterolemia. Another cohort of 20 IMA specimens was stained retrospectively; 10 of those biopsies were from patients that had experienced transient ischemic events peri-operatively in the myocardial area supplied by the IMA. The biopsies were examined histologically and immunohistochemically (rabbit polyclonal ET-1 antiserum, three-step avidin-biotin complex) with regard to their immunoreactivity to tissue ET-1.. An immunoreactivity to ET-1 (graded 0-3) was present in 89% of the biopsies. The reactivity was significantly higher in patients with hypercholesterolemia ( 1.92+/-0.74) when compared to controls (1.0+/-0.63) (P = 0.04). The reactivity was also increased in patients with non-insulin-dependent diabetes mellitus (2.1+/-0.79), when compared to controls (P = 0.02). Mostly transient ischemic events in the area supplied by the IMA seemed to occur more frequently when the biopsies revealed a higher immunoreactivity to ET-1. They showed an increased reactivity to ET-1 (2.27+/-0.76) compared to 10 patients with an uneventful peri-operative course (1.66+/-0.71 ) (P = 0.04).. This study provides evidence that the internal mammary artery is not a passive conduit. Vasospasm or vasoconstriction, in particular at its distal end, may occur more frequently in patients with hypercholesterolemia or diabetes, and may lead to post-operative ischemic events.

Topics: Biopsy; Cohort Studies; Coronary Circulation; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Female; Humans; Hypercholesterolemia; Immunohistochemistry; Internal Mammary-Coronary Artery Anastomosis; Intraoperative Complications; Male; Mammary Arteries; Middle Aged; Myocardial Ischemia; Prospective Studies; Retrospective Studies; Vasoconstriction; Vasoconstrictor Agents

Plasma endothelin-1 was measured around the clock in 72 subjects. Cosinor methods were used to assess circadian and other recurrent variation and trends, that is, the time structure (chronome) of this peptide. Multifactorial analyses of variance and linear regressions assessed chronome alterations associated with different risk factors: diabetes, obesity, high cholesterol, high blood pressure, vascular disease, smoking, and age. The rhythm-adjusted mean (MESOR) of endothelin-1 is elevated in diabetes and vascular disease. Diabetes is also associated with a larger circadian amplitude. A circadian variation in a subgroup of low-risk subjects is modulated by components with both lower and higher frequency.

Topics: Adult; Aged; Circadian Rhythm; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Endothelin-1; Female; Humans; Hypertension; Male; Middle Aged; Periodicity; Regression Analysis; Risk Factors; Time Factors; Vascular Diseases

Endothelin-1 (ET-1), a novel 21-amino acid vasoconstrictive peptide secreted by endothelial cells, has been thought to play a role in various forms of vascular disease. Diabetes mellitus is well known for its association with microvascular damage. To investigate whether ET-1 levels may be related to microangiopathy in diabetes mellitus, plasma ET-1 levels were measured in two groups of diabetic patients: A) 47 patients with non-insulin dependent diabetes mellitus (NIDDM) and retinopathy (28 M, 19 F; mean age 60.7+/-8.5 yrs) but without nephropathy (microalbuminuria < 30 mg/day) and hypertension (SBP < 140, DBP < 90 mmHg); group A was divided in three subgroups based on the severity of retinopathy: a) 16 with background retinopathy; b) 21 with pre-proliferative retinopathy; c) 10 with proliferative retinopathy. B) 8 patients with insulin-dependent diabetes mellitus (IDDM) recently diagnosed (6 M, 2 F; 16.4+/-3.8 yrs) without complications. C) 28 healthy subjects (HS) (16 M, 12 F; 47.8+/-11.8 yrs) as controls. In the NIDDM group the ET-1 concentration was significantly higher (17.3+/-2.4 pg/ml) than both in the HS (8+/-4.7 pg/ml) and IDDM patients (10.2+/-3.7 pg/ml) (p < 0.0001). In the subgroups with retinopathy the ET-1 levels were a) 15.1+/-4.3 pg/ml; b) 22.2+/-6.8 pg/ml and c) 16.6+/-5.1 pg/ml. These values were significantly elevated as compared to HS (p<0.001; p < 0.0001; p < 0.002, respectively), being the highest levels of ET-1 observed in the NIDDM patients with pre-proliferative retinopathy. In conclusion our study revealed that the ET-1 concentrations are elevated in NIDDM patients with retinopathy especially in those patients with pre-proliferative retinopathy.

Topics: Aged; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Endothelin-1; Female; Humans; Male; Middle Aged

Endothelin-1 (ET-1) with its well-known vasoconstrictive and mitogenic action and through its interaction with insulin, blood glucose, and lipids might play an important role in the accelerated atherogenic process in diabetes mellitus.. To determine whether ET-1 levels are indicative of macrovascular disease in diabetes mellitus.. In the present cross-sectional study, plasma ET-1 concentrations were measured in members of three groups. The first group consisted of 20 patients (15 men and five women; aged 56.3 +/- 12.5 years) with non-insulin-dependent diabetes mellitus and coronary artery disease, the second group of 20 patients (16 men and four women, aged 56.9 +/- 11.2 years) with coronary artery disease only, and the third group of 10 healthy subjects who served as controls. ET-1 levels were determined by a radioimmunoassay.. The mean plasma ET-1 levels for the three groups were 3.59 +/- 1.88, 4.31 +/- 1.32, and 4.42 +/- 1.01 pmol/l respectively, and there was no statistically significant difference among the groups (P = 0.23). There was also no correlation between the plasma ET-1 concentration and age, sex, body mass index, triglyceride, total cholesterol, high-, low- and very-low density lipoprotein levels, for all groups, and, for the first group, hemoglobin A1c (HbA1c), the duration of diabetes mellitus.. The plasma ET-1 concentration is not elevated in non-insulin-dependent diabetes mellitus patients with macrovascular disease, which might reflect the fact that its action occurs in a paracrine or an autocrine rather than an endocrine fashion and suggests that ET-1 levels are not necessarily indicative of macrovascular disease in diabetes mellitus.

Topics: Aged; Arteriosclerosis; Coronary Disease; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Endothelin-1; Female; Humans; Male; Middle Aged

Increased levels of endothelin (ET-1), a potent endothelium-derived vasoconstrictive peptide, have been found in plasma from non-insulin dependent diabetic (NIDDM) patients, suggesting that ET-1 might represent a new marker of diabetes-related vascular damage. To elucidate this topic, circulating ET-1 levels were evaluated in 16 NIDDM patients in good metabolic control without either cardiovascular risk factors (obesity, hypertension, smoking, hyperdislipidaemia, etc.) or diabetes-related damage of other districts and in 12 healthy subjects. Retinopathy was assessed by ophthalmological evaluation and its severity determined by Klein criteria. Resulting data showed higher levels of plasma ET-1 in NIDDM patients than in control subjects (0.80 +/- 0.13 vs 0.60 +/- 0.12 pg/mL, p < 0.001). Plasma ET-1 levels were directly correlated with retinopathy degrees in NIDDM patients affected by retinopathy (n = 10; r = 0.368; p = 0.02), and were significantly higher in these latter (n = 10) than in those without retinopathy (n = 6) (0.89 +/- 0.13 vs 0.71 +/- 0.19 pg/mL, p < 0.05). The increased levels of ET-1 could contribute to retinopathy development or, more probably, represent a marker of this diabetes-related complication.

Topics: Adult; Biomarkers; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Endothelin-1; Humans; Male; Middle Aged; Reference Values; Risk Factors

In type II diabetic patients, one can detect several pathologic changes including insulin resistance and hypertension. Sprague-Dawley rats fed a fructose-rich diet (group F) exhibited these characteristic abnormalities within 2 weeks and were an excellent laboratory animal model for research on insulin action and development of hypertension. Since fish oils containing omega-3 fatty acids have a beneficial effect in preventing atherosclerotic diseases, we performed repeated experiments to test the effects of fish oil supplementation in group F rats. Compared with control rats on a normal diet (group C), group F consistently developed hypertriglyceridemia without elevated plasma free fatty acid (FFA), fasting hyperinsulinemia together with fasting hyperglycemia (insulin resistance syndrome), and systolic hypertension within 3 weeks. Insulin-stimulated glucose uptake and insulin binding of adipocytes were significantly reduced. Rats fed the same high-fructose diet but supplemented with fish oil (group O) had alleviation of all of these metabolic defects and a normalized insulin sensitivity and blood pressure. beta-Cell function as shown by plasma glucose and insulin responses to oral glucose remained intact in group F and group O. The plasma endothelin-1 (ET-1) level and ET-1 binding to adipocytes were not different among the three groups. Based on these results, we suggest that dietary high fructose induced hypertriglyceridemia and insulin resistance with normal islet function, and that the induced hypertension was not associated with plasma ET-1 abnormalities and was probably caused by other undefined pathologic changes that can be prevented by dietary omega-3 fatty acids.

Topics: Adipocytes; Animals; Binding, Competitive; Blood Glucose; Blood Pressure; Body Weight; Cohort Studies; Diabetes Mellitus, Type 2; Dietary Supplements; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelin-1; Fish Oils; Fructose; Hypertension; Insulin; Insulin Resistance; Iodine Radioisotopes; Male; Rats; Rats, Sprague-Dawley; Time Factors

Plasma ET-1 was measured around the clock on different calendar dates in healthy subjects and in subjects with diabetes and/or with high blood pressure and/or a history of vascular complications (HVDR). A transverse approach, with each subject contributing a single 24-h mean, assessed any about-weekly or half-weekly variation in ET-1. A circasemiseptan component resolved by single cosinor for nondiabetic (but not for diabetic) HVDR subjects (p = 0.010) differs in its timing of overall high values (p < 0.050) from that found in healthy subjects (p = 0.006). The results are aligned with circasemiseptan patterns in other circulatory variables and morbidity/mortality statistics.

Topics: Adult; Aged; Aged, 80 and over; Blood Pressure; Cardiovascular Diseases; Circadian Rhythm; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Endothelin-1; Female; Humans; Longitudinal Studies; Male; Middle Aged; Periodicity; Risk Factors; Vascular Diseases

1. The obese fa/fa Zucker rat is a genetic model of obesity and insulin resistance which develops a number of metabolic and endocrine features of non-insulin-dependent diabetes, including hypertension, proteinuria and glomerular sclerosis. 2. We have investigated the urinary excretion of the metabolites of thromboxane (thromboxane B2) and prostacyclin (6-keto prostaglandin F1 alpha), and of endothelin and cyclic GMP as markers for changes in the balance of renal haemodynamic factors in the obese Zucker rat. 3. Obese fa/fa Zucker rats were hypertensive compared with their lean counterparts (161 +/- 3 and 138 +/- 3 mmHg respectively, P < 0.01); obese animals were also markedly proteinuric (16.7 +/- 6.7 versus 1.1 +/- 0.1 mg/ml) and albuminuric (8.3 +/- 2.9 versus 0.4 +/- 0.25 mg/ml) and excreted less creatinine than lean animals (all P < 0.01). Urinary excretion of endothelin was greater in obese rats (123 +/- 24 versus 62 +/- 10 pg/15 h, P < 0.05) as was the level of pre-proendothelin mRNA, but excretion of cyclic GMP was depressed (12.5 +/- 1.6 versus 27.2 +/- 3.1 nmol/ 15 h, P < 0.01). Histological examination of kidneys from obese animals showed evidence of focal glomerulosclerosis and cortical tubular damage. 4. These results show that increased urinary endothelin is associated with proteinuria and early stage nephropathy in this animal model of non-insulin-dependent diabetes mellitus. This finding, coupled with a decreased excretion of cyclic GMP, suggests that these increased renal vasoconstrictor/vasodilator forces might contribute to the renal functional changes in non-insulin-dependent diabetes mellitus.

Topics: 6-Ketoprostaglandin F1 alpha; Albuminuria; Animals; Cyclic GMP; Diabetes Mellitus; Diabetes Mellitus, Type 2; Endothelin-1; Immunohistochemistry; Kidney; Male; Obesity; Rats; Rats, Zucker; RNA, Messenger; Statistics, Nonparametric; Thromboxane B2

To evaluate the secretion of vasoactive factors in vascular endothelium of patients with non-insulin-dependent diabetes mellitus (NIDDM) the authors examined 31 NIDDM patients. Of them, 18 had no signs of renal involvement, 13 patients showed apparent diabetic nephropathy (DN). In the former patients the blood contained much greater content of vasodilating factor prostacyclin than of vasoconstricting factor endothelin-1 (ET-1) and thromboxan A2 (TxA2). In diabetic nephropathy the balance of vasoactive factors shifted to predominance of vasoconstrictors ET-1 and TxA2. Such rearrangement of vasoactive factors to higher quantities of vasoconstrictors in diabetes mellitus may initiate or promote progression of diabetic nephropathy with resultant spasm of afferent glomerular vessels, reduced glomerular filtration and renal blood flow rates, arterial hypertension, increased thrombogenesis. Thus, elevated levels of ET-1 and TxA2 in diabetics and their rise with progression of diabetic nephropathy are likely to act as pathogenetic factors underlying onset and progression of nephroangiopathy.

Topics: Albuminuria; Chronic Disease; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Progression; Endothelin-1; Endothelium, Vascular; Epoprostenol; Female; Humans; Male; Middle Aged; Thromboxane A2

Acute hyperinsulinemia does not increase circulating ET-1 levels in subjects with normal and deranged glucose metabolism.

Topics: Adolescent; Adult; Aged; Diabetes Mellitus, Type 2; Endothelin-1; Female; Glucose Clamp Technique; Humans; Hyperinsulinism; Hypoglycemic Agents; Infusions, Intravenous; Insulin; Male; Middle Aged

To assess whether plasma and urinary endothelin-1 (ET-1) values are related to the severity of diabetic nephropathy, we measured plasma and urinary ET-1-like immunoreactivity (ET-1-LI) in 14 healthy subjects, and in 50 normoalbuminuric (group 1), 13 albuminuric (group 2), and 10 renally insufficient (group 3) patients with Type 2 diabetes. Plasma ET-1-LI values were significantly increased in group 3, and correlated positively with serum creatinine levels (r = 0.579, p < 0.01). Urinary ET-1-LI excretion in group 3 (49.3 +/- 7.3 pmol day-1) was significantly higher than that in healthy controls (27.0 +/- 1.1 pmol day-1) and in group 1 (32.2 +/- 2.2 pmol day-1), while that of group 2 (38.8 +/- 5.9 pmol day-1) was also higher than in healthy controls. A significant positive correlation between urinary ET-1-LI and serum creatinine values was also found (r = 0.297, p < 0.05). Trend analysis showed significant linear and quadratic trends in the elevation of plasma ET-1-LI and a significant linear trend in urinary ET-1-LI levels from healthy controls to groups 1, 2 and 3. Our results demonstrate that an increase in plasma and urine ET-1-LI correlates with the severity of diabetic nephropathy.

Topics: Albuminuria; Biomarkers; China; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelin-1; Humans; Kidney Diseases; Middle Aged

To investigate whether circulating endothelin-1 (Et-1) may be related to the increased incidence and severity of ischaemic heart disease in type 2 diabetes mellitus, we compared the concentrations in type 2 diabetic patients and in non-diabetic patients with coronary artery disease (CAD) angiographically documented. Plasma levels of Et-1 were determined in 34 type 2 diabetic patients with CAD (16 with stable angina, 6 with unstable angina, 12 with previous myocardial infarction) and in 19 nondiabetic patients with CAD (4 with stable angina, 5 with unstable angina, 10 with previous myocardial infarction). Fifteen diabetic patients without CAD and 9 healthy volunteers served as control subjects. In the type 2 diabetic patients, the mean Et-1 levels were 3.19 +/- 1.61 pmol/l in those with stable angina, 3.58 +/- 1.92 pmol/l in those with unstable angina, 4.24 +/- 2.53 pmol/l in those with myocardial infarction. These values were not significantly different one another, nor from the values obtained from type 2 diabetic controls (3.64 +/- 2.13 pmol/l). In the non-diabetic patients, the mean Et-1 levels were 3.92 +/- 0.73 pmol/l in those with stable angina, 4.35 +/- 1.67 pmol/l in those with unstable angina, 4.33 +/- 1.66 pmol/l in those with myocardial infarction. These values were not significantly different one another, but significantly higher than those obtained from healthy controls (2.07 +/- 0.67 pmol/l; P < 0.001). No significant differences were found in Et-1 levels between diabetic and non-diabetic patients with stable, unstable angina and previous myocardial infarction. In contrast, a statistically significant difference was found in Et-1 levels between diabetic and non-diabetic control subjects (P < 0.05). In conclusion, similar raised concentrations of Et-1 in diabetic and non-diabetic patients with stable, unstable angina and previous myocardial infarction do not support the hypothesis that higher levels of Et-1 in diabetic patients are responsible for the increased incidence of CAD in diabetes mellitus. However, the raised Et-1 levels found in diabetic patients in the absence of CAD strongly suggest that a generalised endothelial dysfunction, documented in our study by increased levels of Et-1, most probably precedes subsequent cardiovascular diseases.

Topics: Aged; Analysis of Variance; Angina Pectoris; Blood Pressure; Diabetes Mellitus, Type 2; Endothelin-1; Female; Humans; Incidence; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Reference Values

Topics: Adult; Diabetes Mellitus, Type 2; Endothelin-1; Endothelins; Humans; Immunoenzyme Techniques; Middle Aged; Protein Precursors