endothelin-1 and Albuminuria

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

Two syndromes are called syndromes X: cardiac (effort anginal pain, positive exercise tolerance test and absence of angiographically documented critical stenosis in coronary arteries) and metabolic (according to WHO definition: impaired glucose tolerance and insulin resistance and > or = 2 risk factors from the following list: hypertension, dyslipidaemia, visceral obesity and microalbuminuria). Hyperinsulinaemia and endothelial dysfunction are present in both syndromes. The contribution of endothelial nitric oxide synthase gene mutations to the etiology of these syndromes is also studied. Several mechanisms may be involved in the development of endothelial dysfunction, such as reduced synthesis and release of nitric oxide (NO), enhanced inactivation of NO after its release from endothelial cells or enhanced synthesis of vasoconstricting agents. It has been demonstrated that insulin exerts a direct hypertrophic effect on the vascular endothelium and the smooth muscle cells. The hemodynamic properties of insulin have also been discussed. Some findings suggest that in the skeletal muscle circulation, insulin stimulates both endothelin-1 (ET-1) and nitric oxide activity and an imbalance between the release of these two substances may be involved in the pathophysiology of endothelial dysfunction.

Topics: Albuminuria; Endothelin-1; Humans; Hyperinsulinism; Hyperlipidemias; Hypertension; Insulin; Metabolic Syndrome; Microvascular Angina; Mutation; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type III; Obesity; Risk Factors

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

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

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

To study correlations between severity of hyperuricemia, endothelial dysfunction (ED) and arterial atherosclerosis (AS).. A total of 50 patients with essential hypertension of degree I-II free of associated clinical conditions entered the trial. The study group consisted of 40 patients with hyperuricemia, the control group of 10 patients with normal blood serum levels of uric acid.. The study group patients versus controls had significantly higher albuminuria (93.5 +/- 1.7 and 60.7 +/- 2.2 mg/l; p < 0.001), plasmic concentration of endotheline-1 (6.8 +/- 0.3 and 4.9 +/- 0.2 pg/ml; p < 0.001)and thickness of the intima-media complex of the common carotid artery (1.36 +/- 0.02 and 1.1 +/- 0.04; p < 0.001). All the indices correlated directly and significantly.. Patients with arterial hypertension of the first-second degree with persistent elevated levels of uric acid in blood serum had significantly higher levels of ED markers: albuminuria, plasmic endothelin concentration. Hyperuricemia and ED in such patients lead to more active progression of atherosclerotic vascular lesion.

Topics: Adult; Albuminuria; Carotid Intima-Media Thickness; Endothelin-1; Endothelium, Vascular; Female; Humans; Hypertension; Hyperuricemia; Kidney Diseases; Male; Middle Aged; Uric Acid

The aim of the study was to evaluate whether normoalbuminuric type 1 diabetic patients with diabetic retinopathy (DR) have an impaired tubular response to desmopressin (dDAVP, a synthetic analog of vasopressin) administration, and its relationship with plasma and urine endothelin-1 (ET-1) levels.. This was an interventional case-control study.. The study was conducted at a referral center.. Fifteen normoalbuminuric type 1 diabetic patients with DR were compared with 30 normoalbuminuric type 1 diabetic patients without DR. Both groups were matched by age, gender, body mass index, glycosylated hemoglobin, and the main laboratory markers of kidney function.. After a 12-h period of water deprivation, dDAVP (0.3 microg/kg) was infused over 20 min. Urine was collected at baseline and 1, 2, and 3 h after dDAVP administration. ET-1 was assessed by ELISA.. dDAVP induced a lower rise in urine osmolality in patients with DR (from 650 +/- 206 to 754 +/- 224 mosmol/kg; P = 0.02) than in diabetic patients without DR (from 714 +/- 194 to 905 +/- 163 mosmol/kg; P < 0.0001). In addition, fractional excretion of Na+ decreased in patients without DR (from 0.45 +/- 0.30 to 0.29 +/- 0.29%; P = 0.04) but not in the diabetic patients with DR (from 0.36 +/- 0.22 to 0.36 +/- 0.40%; P = 0.96). Plasma ET-1 levels were inversely correlated with the response of urinary osmolality after dDAVP administration (r = -0.62; P = 0.008).. Normoalbuminuric type 1 diabetic patients with DR have impaired renal response to dDAVP that is related to plasma ET-1 levels. Further studies are required to elucidate whether this tubular resistance to dDAVP might favor dehydration in these patients.

Topics: Adult; Albuminuria; Creatinine; Deamino Arginine Vasopressin; Diabetes Mellitus, Type 1; Diabetic Retinopathy; Endothelin-1; Female; Humans; Kidney Tubules; Male; Middle Aged; Osmolar Concentration; Young Adult

To observe the clinical effect of integrative medicinal therapy in treating children Henoch-Schonlein purpura (HSP) and its preventive effect on complicated renal impairment.. One hundred and twenty children with HSP were equally randomized into two groups, the treated group and the control group. Both were treated with conventional Western medical therapy, but Sanhuang Qingxue Yin (SQY, a Chinese herbal drug) was given additionally to the treated group. Besides, a group consisted of 30 healthy children was set up as a normal control. Changes of symptoms, physical signs, routine urine, plasma endothelin-1 (ET-1) and urinary levels of beta2-microglobulin (beta2-MG), albumin (ALB) and immunoglobulin G (IgG) before and after treatment were observed, and the recurrence was monitored.. The cure rate and the total effective rate in the treated group were 80.0% and 98.3%, while those in the control group were 61.7% and 88.3%, showing significant differences between groups (P < 0.05); the disappearance time of clinical symptoms was shorter in the treated group than in the control group, also showing a significant difference (P < 0.01); after 1-month treatment, levels of plasma ET-1, and urinary beta2-MG, ALB and IgG were improved in the treated group, reaching the levels opproximate to those in the normal control (P > 0.05), significant difference was shown as compared with those in the control group and with those before treatment respectively (P < 0.01, P < 0.05). The recurrent rate was 13.33% in the treated group and 30.0% in the control group, and they were statistically different (P < 0.05).. The integrative medicinal therapy is good for treating HSP in children, it could not only obviously relieve clinical symptoms, shorten the illness course and reduce the recurrent rate, but also effectively prevent the occurrence of renal impairment.

Topics: Adolescent; Albuminuria; beta 2-Microglobulin; Child; Child, Preschool; Drug Therapy, Combination; Drugs, Chinese Herbal; Endothelin-1; Female; Humans; IgA Vasculitis; Immunoglobulin G; Integrative Medicine; Kidney Diseases; Male; Phytotherapy

In order to explore the therapeutic effect of tongxinluo capsule (TXLC) on diabetic nephropathy, the influence on plasma endothelin (ET-1) level of the drug was observed.. All the 63 patients enrolled were randomly divided into the treatment group and control group. They were all treated with low protein diabetic diet, oral administration of hypoglycemic or injection of insulin, calcium antagonist according to level of blood pressure and supportive symptomatic treatment. To the treated group, 2 capsules of TXLC were given additionally three times a day. The efficacy was evaluated after 8 weeks' treatment. The chief indices observed before and after treatment were endogenous creatinine clearance rate (CCr), urinary albumin excretion rate (UAER), urinary beta2-microglobulin (beta2-MG), fasting blood-glucose (FBG) and ET-1.. Before treatment, no significant difference was shown in all the tested indices between the treated group and the control group. After treatment, levels of CCr, UAER, beta2-MG, ET-1 and FBG significantly changed in the treated group, showing significant difference as compared with those before treatment (P < 0.05). Moreover, comparison of these indices in the two groups after treatment, excepting FBG, also showed statistical significance (P < 0.01).. TXLC shows obvious effect in reducing plasma ET-1 and UAER, it is definitely effective in repairing the renal tubular interstitial damage, and effectively delay the progress of diabetic nephropathy, improve the renal function, and is favorable to ameliorate hyperglycemia auxiliarily.

Topics: Albuminuria; Capsules; Diabetic Nephropathies; Drugs, Chinese Herbal; Endothelin-1; Female; Humans; Male; Phytotherapy

Increases in microalbuminuria and endothelin (ET-1) are involved in the development of ulcerative colitis (UC) and in its progress. Because granulocyte and monocyte adsorption apheresis has proven to be useful in the treatment of UC, we examined whether urinary albumin excretion and plasma ET-1 concentrations are altered and whether granulocyte and monocyte adsorption apheresis affects the concentrations of these two factors in patients with active UC.. Twenty patients with active UC and 20 age-matched healthy volunteers (our hospital staffs) were included in this study. UC patients were randomly divided into two treatment groups: a granulocyte and monocyte adsorption treatment group (n = 10) and a conventional treatment group (n = 10). The urine albumin/creatinine ratio, plasma ET-1 concentration and tumor necrosis factor (TNF)-alpha were determined before and after treatment and compared between 2 treatment groups. The 10 adsorption treatment patients underwent 5 consecutive weekly apheresis sessions, each of 60 min duration at a flow rate of 30 ml/min.. The urine albumin/creatinine ratio in UC patients (6.4 +/- 2.2 mg/mmol) were higher than that in healthy subjects (1.0 +/- 0.7 mg/mmol, p < 0.01). In addition, the plasma ET-1 level in UC patients (3.5 +/-1.5 pg/ml) was higher than that in healthy subjects (0.8 +/- 0.4 pg/ml, p < 0.01). Plasma TNF-alpha was detected in UC patients (18.8 +/- 8.4 pg/ml), but not in healthy subjects. The urine albumin/creatinine ratio was highly correlated with the plasma ET-1 level (r = 0.62; p < 0.01) and plasma TNF-a level (r = 0.66, p < 0.01). Granulocyte and monocyte adsorption apheresis reduced the urine albumin/ creatinine ratio from 6.6 +/- 2.4 to 1.8 +/- 0.6 mg/mmol (p < 0.01), reduced the plasma ET-1 level from 3.7 +/- 1.6 to 1.4 +/- 0.6 pg/ml (p < 0.05) and reduced the plasma TNF-alpha from 19.2 +/- 8.6 to 3.8 +/- 1.2 pg/ml (p < 0.01). Conventional treatment did not affect these factors.. Our data suggest that increases in the urine albumin/creatinine ratio, ET-1 and TNF-alpha play an important role in active UC and that granulocyte and monocyte adsorption apheresis is effective in ameliorating such increases.

Topics: Adsorption; Adult; Albuminuria; Colitis, Ulcerative; Creatinine; Defecation; Endothelin-1; Female; Granulocytes; Humans; Leukapheresis; Leukocyte Count; Male; Monocytes; Tumor Necrosis Factor-alpha

Adrenomedullin (ADM) infusion increases salt excretion in the rat. However, there is no evidence that this substance is related to changes in salt intake in humans. In this study we sought whether the urinary excretion rate of this autacoid is related to salt intake and by the expected changes in arterial pressure in patients with mild essential hypertension. The influence of salt intake on the renal excretion of ADM was investigated in 55 hypertensive patients in a double blind, randomized and crossover study comparing a 2-week 50 mmol/day salt intake period with a 150 mmol/day salt intake period. Twenty-four-hour ADM and endothelin-1 (ET-1) excretion rate were measured by radioimmunoassay on preextracted urinary samples (intraassay confidence variable <8%). The antibodies used in these assays had minimal ADM-ET-1 cross-reactivity (<1%). Twenty-four-hour microalbuminuria was measured by nephelometry. On univariate analysis changes in urinary ADM were significantly related to those in salt excretion (r = 0.33, P = .01) as well as to changes in urinary ET-1 (r = 0.56, P = .0001). Furthermore, changes in urinary albumin excretion were related to those in urinary ET-1 (r = 0.26, P = .05), but were independent of those in urinary ADM (P = .19). In a multiple regression model including age, sex, body mass index, and changes in systolic pressure, plasma renin activity and plasma aldosterone and urine volume, salt excretion resulted as the stronger independent predictor of urinary ADM (r = 0.33, P = .01). However, changes in urinary salt lost prediction power (P = .11) for urinary ADM when urinary ET-1 was introduced into the model. In this model (multiple r = 0.31) urinary ET-1 resulted to be the only independent predictor of urinary ADM (beta = 0.56, P = .0001). This study is the first to show that the renal excretion of ADM is related to changes in salt intake and that it is tightly linked to that of ET-1. The data support the notion that these autacoids play a role in the regulation of sodium metabolism in patients with mild hypertension. The intercorrelations between ET-1, ADM, and microalbuminuria are compatible with the hypothesis that ET-1 is involved in a salt-induced increase in glomerular pressure and suggest that ADM may act as a counterregulatory factor in this situation.

Topics: Adrenomedullin; Adult; Aged; Albuminuria; Angiotensins; Cross-Over Studies; Double-Blind Method; Endothelin-1; Female; Humans; Hypertension; Male; Middle Aged; Natriuresis; Peptides; Radioimmunoassay; Renin; Sodium Chloride, Dietary; Vasodilator Agents

The pathogenesis of antiphospholipid antibody (aPL) related thrombosis is multifactorial and includes, amongst others, enhanced coagulation activation measured as prothrombin fragment 1 + 2 (F1 + 2), elevated plasma levels of von Willebrand factor (vWF), plasminogen activator inhibitor (PAI) and endothelin-1 (ET-1) as well as heightened thromboxane generation and lipid peroxidation. To evaluate the antioxidant susceptibility of some of the above pathways, probucol (500 mg/d orally, a cholesterol lowering agent bearing antioxidant properties) was administered for a three week period to 14 subjects with aPL and to seven healthy controls. At baseline aPL participants showed higher plasma levels of vWF (P = 0.006), ET-1 (P = 0.0002) and enhanced urinary excretion of 11-dehydro-thromboxane-B2 (TXB2) (P = 0.0004), F2-isoprostanes (marker of lipid peroxidation) (P = 0.02) and albumin (P = 0.04) than controls. In the aPL group baseline IgG anticardiolipin (aCL) titre positively related with urinary TXB2 (r2 = 0.43, P = 0.01) and inversely with urinary NOx (r2 = -0.6, P = 0.005) whereas urinary NOx and TXB2 were negatively correlated (r2 = -0.42, P = 0.01). After the treatment period significant decreases from baseline values were noted for PAI (P = 0.01), ET-1 (P = 0.006), TXB2 (P = 0.02), F2-isoprostanes (P = 0.01) and albuminuria (P = 0.01) in aPL participants but not in controls. These pilot data support oxidative sensitive mechanisms and a potential role for antioxidant treatment in the pathogenesis of aPL induced vasculopathy.

Topics: Adult; Albuminuria; Antibodies, Antiphospholipid; Anticholesteremic Agents; Anticoagulants; Antioxidants; Antiphospholipid Syndrome; Arachidonic Acids; Creatinine; Endothelin-1; Female; Humans; Lipids; Male; Middle Aged; Nitric Oxide; Pilot Projects; Probucol; Prothrombin; Thrombosis; Thromboxane B2; von Willebrand Factor; Warfarin

Endothelin (ET) is a potent vasoconstrictive peptide that may play a role in vascular pathology in general and diabetic nephropathy in particular. The aim of this study was to investigate (1) alterations of urinary ET1 (UET1) in adolescents and young adults with insulin-dependent diabetes mellitus (IDDM) and (2) the relation of UET1 to other indices of diabetic nephropathy and to risk factors of diabetic angiopathy in general. In 130 IDDM subjects aged 15.2+/-4.9 years with a diabetes duration of 7.3+/-5.1 years, UET1 by radioimmunoassay, urinary albumin by nephelometry, plasma renin by immunoradiometric assay, hemoglobin A1c (HbA1c) by high-performance liquid chromatography, and routine biochemistry analyses were determined. Forty-eight controls, healthy siblings of the diabetics of comparable age, were similarly studied. Total 24-hour UET1 excretion was higher in diabetics than in controls (10,866+/-7,270 and 6,598+/-3,294 pg/24 h, respectively, P=.000). This difference was also noted if male and female diabetics were separately compared with controls. In diabetics with normoalbuminuria (<20 microg/min), total 24-hour UET1 excretion was also higher than in controls (P=.002). In diabetics but not in controls, 24-hour UET1 values were higher in males than in females (P=.018). In IDDM subjects, UET1 showed a linear relationship with age (P=.002), urinary albumin (P=.000), serum creatinine (P=.001), systolic blood pressure (P=.038), triglycerides (P=.003), and HbA1c (P=.041). Multiple regression analysis demonstrated that the variables interacting independently with UET1 were urinary albumin (P=.003) and serum creatinine (P=.038). UET1 is elevated early (in adolescence) in IDDM subjects, and it is positively correlated with the degree of albuminuria. These data suggest that the amount of UET1 possibly reflects the severity of diabetic renovascular damage. It may thus be speculated that UET1 could be used as another index of diabetic nephropathy or its progress.

Topics: Adolescent; Adult; Albuminuria; Blood Pressure; Child; Diabetes Mellitus, Type 1; Diabetic Angiopathies; Endothelin-1; Female; Humans; Male

Topics: Albuminuria; Atrasentan; Diabetes Mellitus; Diabetic Nephropathies; Endothelin A Receptor Antagonists; Endothelin Receptor Antagonists; Endothelin-1; Humans; Pyrrolidines

Emerging evidence of crosstalk between glomerular cells in pathological settings provides opportunities for novel therapeutic discovery. Here we investigated underlying mechanisms of early events leading to filtration barrier defects of podocyte and glomerular endothelial cell crosstalk in the mouse models of primary podocytopathy (podocyte specific transforming growth factor-β receptor 1 signaling activation) or Adriamycin nephropathy. We found that glomerular endothelial surface layer degradation and albuminuria preceded podocyte foot process effacement. These abnormalities were prevented by endothelin receptor-A antagonism and mitochondrial reactive oxygen species scavenging. Additional studies confirmed increased heparanase and hyaluronoglucosaminidase gene expression in glomerular endothelial cells in response to podocyte-released factors and to endothelin-1. Atomic force microscopy measurements showed a significant reduction in the endothelial surface layer by endothelin-1 and podocyte-released factors, which could be prevented by endothelin receptor-A but not endothelin receptor-B antagonism. Thus, our studies provide evidence of early crosstalk between activated podocytes and glomerular endothelial cells resulting in loss of endothelial surface layer, glomerular endothelial cell injury and albuminuria. Hence, activation of endothelin-1-endothelin receptor-A and mitochondrial reactive oxygen species contribute to the pathogenesis of primary podocytopathies in experimental focal segmental glomerulosclerosis.

Topics: Albuminuria; Animals; Capillaries; Cell Communication; Disease Models, Animal; Doxorubicin; Endothelial Cells; Endothelin A Receptor Antagonists; Endothelin B Receptor Antagonists; Endothelin-1; Endothelium, Vascular; Humans; Kidney Glomerulus; Mice; Mice, Transgenic; Microscopy, Electron, Scanning; Mitochondria; Podocytes; Reactive Oxygen Species; Receptor, Endothelin A; Receptor, Endothelin B; Receptor, Transforming Growth Factor-beta Type I

Topics: Albuminuria; Analysis of Variance; Animals; Blood Pressure Determination; Endothelin-1; Female; Gene Expression Regulation, Developmental; Immunohistochemistry; Mice; Mice, Inbred C57BL; Pre-Eclampsia; Pregnancy; Pregnancy, Animal; Real-Time Polymerase Chain Reaction; Reference Values; Risk Assessment; Vascular Endothelial Growth Factor Receptor-1

The molecular signaling mechanisms between glomerular cell types during initiation/progression of diabetic kidney disease (DKD) remain poorly understood. We compared the early transcriptome profile between DKD-resistant C57BL/6J and DKD-susceptible DBA/2J (D2) glomeruli and demonstrated a significant downregulation of essential mitochondrial genes in glomeruli from diabetic D2 mice, but not in C57BL/6J, with comparable hyperglycemia. Diabetic D2 mice manifested increased mitochondrial DNA lesions (8-oxoguanine) exclusively localized to glomerular endothelial cells after 3 weeks of diabetes, and these accumulated over time in addition to increased urine secretion of 8-oxo-deoxyguanosine. Detailed assessment of glomerular capillaries from diabetic D2 mice demonstrated early signs of endothelial injury and loss of fenestrae. Glomerular endothelial mitochondrial dysfunction was associated with increased glomerular endothelin-1 receptor type A (Ednra) expression and increased circulating endothelin-1 (Edn1). Selective Ednra blockade or mitochondrial-targeted reactive oxygen species scavenging prevented mitochondrial oxidative stress of endothelial cells and ameliorated diabetes-induced endothelial injury, podocyte loss, albuminuria, and glomerulosclerosis. In human DKD, increased urine 8-oxo-deoxyguanosine was associated with rapid DKD progression, and biopsies from patients with DKD showed increased mitochondrial DNA damage associated with glomerular endothelial EDNRA expression. Our studies show that DKD susceptibility was linked to mitochondrial dysfunction, mediated largely by Edn1-Ednra in glomerular endothelial cells representing an early event in DKD progression, and suggest that cross talk between glomerular endothelial injury and podocytes leads to defects and depletion, albuminuria, and glomerulosclerosis.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Albuminuria; Animals; Antioxidants; Chromatography, High Pressure Liquid; Deoxyguanosine; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Disease Susceptibility; DNA, Mitochondrial; Endothelin-1; Endothelium; Enzyme-Linked Immunosorbent Assay; Female; Flow Cytometry; Humans; Kidney Glomerulus; Male; Mesangial Cells; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Microscopy, Electron, Scanning; Middle Aged; Mitochondria; Organophosphorus Compounds; Oxygen Consumption; Piperidines; Podocytes; Real-Time Polymerase Chain Reaction; Receptor, Endothelin A; Signal Transduction; Young Adult

Erectile dysfunction (ED) is a predictor or marker of coronary artery disease in patients at high risk of cardiovascular diseases. The aim of this study was to investigate the prevalence of ED in patients with acute myocardial infarction (AMI) and after 2 years of follow-up, and to determine the association between ED and the concentrations of the markers of inflammation, endothelial dysfunction and oxidative stress which were measured on the third day after hospital admission.. The study included 80 patients aged 62.25 ± 10.47 years. The primary endpoints of interest were re-hospitalization due to cardiovascular causes and death during the 2 year period after hospital-ization. The Sexual Health Inventory for Men (SHIM) was assessed at the point of hospital discharge and 24 months thereafter.. 40.1% of patients had some degree of ED. The percentage of patients without ED increased (13.2%), while the percentage of patients with severe ED significantly decreased (14.7%) after 2 years. Patients with ED had significantly higher B-type natriuretic peptide (BNP) levels and decreased levels of nitric-oxide. During the 2 years of follow-up, 9 patients died (6.5% without ED, 68.6% with ED) (c2 = 7.19, p = 0.015). During the same time period, 22 (27.5%) patients were re-hospitalized due to cardiovascular causes, of whom 59.1% had ED at hospital admission (p < 0.05).. Low levels of nitric-oxide were the best predictors of ED during AMI and after 2 years. ED predicted the worst outcomes of AMI: death and re-hospitalization. Lifestyle changes and nitric- -oxide donors could assist in the treatment of ED and in the improvement of long-term prognosis for AMI. (Cardiol J 2017; 24, 4: 393-402).

Topics: Adult; Aged; Aged, 80 and over; Albuminuria; Biomarkers; Endothelin-1; Endothelium, Vascular; Erectile Dysfunction; Humans; Inflammation Mediators; Male; Middle Aged; Nitric Oxide; Non-ST Elevated Myocardial Infarction; Oxidative Stress; Patient Readmission; Penile Erection; Prevalence; Prospective Studies; Risk Factors; Serbia; ST Elevation Myocardial Infarction; Surveys and Questionnaires; Time Factors; Treatment Outcome

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

Objective Endothelial dysfunction (ED) plays an important role in the pathogenesis of diabetic nephropathy. The purpose of the study was to determine flow mediated endothelial dependent vasodilatation (FMD) measurements and serum soluble (s) endothelin-1 (ET-1), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1) levels in patients with type 1 diabetes mellitus (T1DM) with or without increased urinary albumin excretion (UAE) and compare them with the healthy controls. Subjects and methods Seventy three patients with T1DM were enrolled. Patients were divided into two subgroups according to microalbumin measurements in 24-hr urine collections. The diabetic patients without microalbuminuria (41 patients) were defined as Group I and those with microalbuminuria (32 patients) were defined as group II. A hundred age and sex matched healthy subjects participated as the control group (Group III). Serum sET-1, sICAM-1, sVCAM-1 levels and FMD measurements were determined in all participants. Results Median FMD measurement was significantly lower in the diabetic groups compared with the control group (6.6, 6.4 and 7.8% in Group I, II and III, respectively) (p < 0.05). FMD was negatively correlated with age (p = 0.042). Median serum sICAM-1 level was higher in the patient groups compared to the control group (p < 0.05). Median serum sVCAM-1 level was higher in the group of patients with increased albuminuria compared to the normoalbuinuric and the control group (p < 0.05). Serum sVCAM-1 level was found to be positively correlated with degree of urinary albumin excretion (p < 0.001). Conclusion We assume that sVCAM-1 may be used as a predictive marker for risk stratification for nephropathy development and progression.

Topics: Adult; Albuminuria; Analysis of Variance; Biomarkers; Blood Flow Velocity; Case-Control Studies; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Endothelin-1; Endothelium, Vascular; Female; Humans; Intercellular Adhesion Molecule-1; Male; Predictive Value of Tests; Reference Values; Risk Factors; Statistics, Nonparametric; Vascular Cell Adhesion Molecule-1; Vasodilation

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

In diabetes, hyperglycaemia causes up-regulation of endothelin 1 (ET-1) and transforming growth factor beta 1 (TGF-β1). Previously we showed glucose reduces sirtuin1 (SIRT1), a class III histone deacetylase. Here, we investigated the regulatory role of SIRT1 on ET-1 and TGF-β1 expression. Human microvascular endothelial cells were examined following incubation with 25 mmol/l glucose (HG) and 5 mmol/l glucose (NG) with or without SIRT1 or histone acetylase p300 overexpression or knockdown. mRNA expressions of ET-1, TGF-β1, SIRT1, p300 and collagen 1α(I) were examined. SIRT1 enzyme activity, ET-1 and TGF-β1 protein levels were measured. Histone acetylation and endothelial permeability were further investigated. Similar analyses were performed in the kidneys and retinas of SIRT1 overexpressing transgenic mice with or without streptozotocin induced diabetes. Renal functions were evaluated. In the endothelial cells (ECs), HG caused increased permeability and escalated production of ET-1, TGF-β1, collagen Iα(I). These cells also showed increased p300 expression, histone acetylation and reduced SIRT1 levels. These changes were rectified in the ECs following p300 silencing or by SIRT1 overexpression, whereas SIRT1 knockdown or p300 overexpression in NG mimicked the effects of HG. High ET-1 and TGF-β1 levels were seen in the kidneys and retinas of diabetic mice along with micro-albuminuria and increased fibronectin protein (marker of glucose-induced cell injury) levels. Interestingly, these detrimental changes were blunted in SIRT1 overexpressing transgenic mice with diabetes. This study showed a novel SIRT1 mediated protection against renal and retinal injury in diabetes, regulated through p300, ET-1 and TGF-β1.

Topics: Albuminuria; Animals; Cell Membrane Permeability; Collagen Type I; Diabetes Mellitus, Experimental; Endothelial Cells; Endothelin-1; Fibronectins; Glucose; HEK293 Cells; Humans; Kidney; Kidney Function Tests; Male; Mice, Inbred C57BL; Mice, Transgenic; Microvessels; Oxidative Stress; p300-CBP Transcription Factors; Real-Time Polymerase Chain Reaction; Retina; Sirtuin 1; Transforming Growth Factor beta1; Up-Regulation

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

To identify the risk factors of kidney injuries in hypertensive patients with uric acid (UA) metabolic disorders in order to choose the optimal management tactics, by analyzing the changes in markers for endothelial dysfunction (endothelin-1 (ET-1), microalbuminuria (MAU), intima-media thickness (IMT)) and tubulointerstitial tissue lesion (beta2-microglobulin (beta2-MG, monocyte chemotactic protein-1 (MCP-1)).. Eighty-one patients with grade 1 hypertension without associated diseases, diabetes mellitus, or metabolic syndrome were examined. There were 3 study groups: 1) hyperuricosuria (n = 7); 2) hyperuricemia (n = 53); 3) hyperuricemia and renal failure (n = 6); and a control group of 15 hypertensive patients without UA metabolic disorders who were matched for age and gender with the patients of the study groups.. The hypertensive patients with hyperuricemia, as compared with those without UA metabolic disorders, showed higher plasma concentrations of ET-1 (p = 0.003) and MAU (p = 0.009) and more marked increases in common carotid IMT (p = 0.044), urinary excretion of beta2-MG (p = 0.010), and MCP-1 (p = 0.030). There were direct correlations between all the examined biomarkers and the degree of uricemia (Rs = 0.453; p < 0.001; Rs = 0.411; p < 0.001; Rs = 0.322; p = 0.067; Rs = 0.537; p < 0.001; and Rs = 0.318; p = 0.004, respectively) and between the markers of endothelial dysfunction and those of tubulointerstitial tissue lesion (Rs = 0.295 for ET-1 and MCP-1; p = 0.008; Rs = 0.399 for ET-1 and beta2-MG; p < 0.001; Rs = 0.462 for MAU and beta2-MG; p < 0.001; and Rs = 0.188 for MAU and MCP-1; p = 0.094). Multivariate analysis of the clinical and laboratory parameters under study confirmed the role of serum MCP-1, beta2-MG, MAU, creatinine levels as independent predictors for decreased relative urinary gravity, the clinical sign of tubulointerstitial tissue lesion/fibrosis, and that of a wider range of the indicators, such as MAU, ventricular septal thickness, glomerular filtration rate, relative urinary gravity, systolic blood pressure, MPC-1, low-density lipoproteins, as risk factors for renal filtrating dysfunction.

Topics: Albuminuria; beta 2-Microglobulin; Biomarkers; Chemokine CCL2; Comorbidity; Endothelin-1; Endothelium; Female; Humans; Hypertension; Hyperuricemia; Male; Metabolic Diseases; Middle Aged; Nephritis, Interstitial; Renal Insufficiency; Risk Factors; Uric Acid

Excess soluble fms-like tyrosine kinase 1 (sFlt-1) of vascular endothelial growth factor receptor 1 secreted from the placenta causes pre-eclampsia-like features by antagonizing vascular endothelial growth factor signaling, which can lead to reduced endothelial nitric oxide synthase (eNOS) activity; the effect of this concomitant decrease in eNOS activity is unknown. We tested whether the decrease in nitric oxide occurring in female mice lacking eNOS aggravates the pre-eclampsia-like phenotype induced by increased sFlt-1. Untreated eNOS-deficient female mice had higher BP than wild-type mice. Adenovirus-mediated overexpression of sFlt-1 increased systolic BP by approximately 27 mmHg and led to severe loss of fenestration of glomerular capillary endothelial cells in both eNOS-deficient and wild-type mice. However, only the eNOS-deficient sFlt-1 mice exhibited severe foot process effacement. Compared with wild-type sFlt-1 mice, eNOS-deficient sFlt-1 mice also showed markedly higher urinary albumin excretion (467±74 versus 174±23 μg/d), lower creatinine clearance (126±29 versus 452±63 μl/min), and more severe endotheliosis. Expression of preproendothelin-1 (ET-1) and its ET(A) receptor in the kidney was higher in eNOS-deficient sFlt-1 mice than in wild-type sFlt-1 mice. Furthermore, the selective ET(A) receptor antagonist ambrisentan attenuated the increases in BP and urinary albumin excretion and ameliorated endotheliosis in both wild-type and eNOS-deficient sFlt-1 mice. Ambrisentan improved creatinine clearance and podocyte effacement in eNOS-deficient sFlt-1 mice. In conclusion, reduced maternal eNOS/nitric oxide exacerbates the sFlt1-related pre-eclampsia-like phenotype through activation of the endothelin system.

Topics: Albuminuria; Animals; Disease Models, Animal; Endothelin-1; Female; Glomerular Filtration Rate; Mice; Mice, Inbred C57BL; Nitric Oxide Synthase Type III; Phenotype; Phenylpropionates; Placenta; Pre-Eclampsia; Pregnancy; Pregnancy, Animal; Pyridazines; Random Allocation; Receptors, Endothelin; Sensitivity and Specificity; Vascular Endothelial Growth Factor Receptor-1

Diabetic nephropathy is a complication of diabetes mellitus leading to end-stage renal disease. Oxidative stress and inflammation play a major role in the pathogenesis of diabetic nephropathy. Green tea, known for its antioxidant and anti-inflammatory properties, has been shown to be renoprotective. We hypothesized that (+)-catechin (CTN), a component of green tea, is responsible for the renoprotection. Our investigation of the therapeutic potential of CTN in streptozotocin-induced diabetic rats demonstrated for the first time that the effects of CTN treatment were comparable with the effects of an angiotensin-converting enzyme inhibitor (ACEi) enalapril for the treatment of albumin excretion. After 12 weeks of CTN treatment with 35 mg/d in the drinking water, urinary albumin excretion and plasma creatinine concentrations in all the diabetic treatment groups were reduced, compared with the diabetic group with no treatment. Urine creatinine and creatinine clearance were higher in diabetic groups treated with CTN and ACEi compared with the diabetic group with no treatment. Endothelin 1, lipid peroxidation, concentration of alanine transferase enzyme, and expression of fibronectin were lower in all the treatment groups compared with the diabetic group with no treatment. Concentrations of free thiols were higher in the CTN-treated group compared with the diabetic rats with no treatment. Our findings suggest that CTN has renoprotective properties comparable with ACEi, and coadministration of CTN and enalapril might be useful in reducing albumin excretion as well as improving endothelial function. (+)-Catechin might be successfully used in the future for clinical situations where ACEi is poorly tolerated or contraindicated.

Topics: Alanine Transaminase; Albuminuria; Angiotensin-Converting Enzyme Inhibitors; Animals; Anti-Inflammatory Agents; Antioxidants; Camellia sinensis; Catechin; Creatinine; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Disease Models, Animal; Enalapril; Endothelin-1; Fibronectins; Lipid Peroxidation; Male; Oxidative Stress; Phytotherapy; Plant Extracts; Rats; Rats, Sprague-Dawley; Sulfhydryl Compounds

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-1 (ET-1) is a vasoactive peptide with vasoconstrictor and mitogenic properties. We investigated whether plasma levels of C-terminal pro-ET-1 (CT-proET-1), a newly described stable fragment of the ET-1 precursor, are associated with target-organ damage in hypertension.. Participants included 981 African Americans (65 ± 9 years, 71% women) and 812 non-Hispanic whites (61 ± 9 years, 54% women) ascertained from sibships with hypertension. We measured plasma CT-proET-1 by an immunoluminometric assay. Measures of target-organ damage included the ankle-brachial index (ABI) and urinary albumin:creatinine ratio (UACR). Multivariable regressions analyses were employed to assess whether plasma CT-proET-1 levels were independently associated with ABI and UACR.. In hypertensive African Americans, higher plasma levels of CT-proET-1 were significantly associated with lower ABI (P < 0.01) and higher UACR (P < 0.01). After adjustment for age, sex, body mass index, systolic blood pressure (SBP) and diastolic blood pressure (BP), diabetes, serum glucose, insulin use, estimated glomerular filtration rate (eGFR), history of smoking, total and high-density lipoprotein cholesterol, medication use, and previous history of myocardial infarction (MI) or stroke, higher plasma levels of CT-proET-1 remained significantly associated with lower ABI (P < 0.01) and higher UACR (P = 0.02). In non-Hispanic white hypertensives, higher plasma levels of CT-proET-1 were weakly associated with higher UACR (P = 0.02) and with lower ABI (P = 0.07). After adjustment for the relevant covariates, no statistically significant associations between CT-proET-1 and ABI or UACR were present in whites.. Plasma levels of CT-proET-1 were independently associated with lower ABI and greater UACR in African American but not non-Hispanic white adults with hypertension.

Topics: Aged; Albuminuria; Ankle Brachial Index; Black or African American; Creatinine; Endothelin-1; Female; Humans; Hypertension, Renal; Male; Middle Aged; Multivariate Analysis; Protein Structure, Tertiary; Regression Analysis; Risk Factors; White People

The relationship between angiotensin II (ANG II) and endothelin-1 (ET-1) is known to be complex; both peptides can initiate and potentiate the gene expression of each other. This pilot study investigated the effects of the AT(1) receptor blocker losartan or the direct renin inhibitor aliskiren on mean arterial pressure (MAP) and albuminuria and the renal ANG II and ET-1 levels. 3-month-old male Ren-2 transgenic rats (TGR) were treated either with losartan (5 mg kg(-1) day(-1)) or aliskiren (10 mg kg(-1) day(-1)) for 10 weeks. At the end of the experiment, rats were decapitated and cortical and papillary parts of kidneys were separated. Plasma and tissue ANG II levels were measured by RIA and tissue ET-1 concentrations by ELISA. In all four groups of animals ET-1 levels were lowest in renal cortex and more than 100-fold higher in the papilla. Cortical and papillary ET-1 concentrations in untreated TGR significantly exceeded those of control HanSD rats and were significantly depressed by both drugs. In both strains, papillary ANG II concentrations were moderately but significantly higher than cortical ANG II, TGR exhibited higher ANG II levels both in cortex and papilla as compared to control HanSD rats. Aliskiren and losartan at the doses used depressed similarly the levels of ANG II in cortex and papilla and reduced ET-1 significantly in the renal cortex and papilla below control levels in HanSD rats. Albuminuria, which was more than twice as high in TGR as in HanSD rats, was normalized with aliskiren and reduced by 28% with losartan, although MAP was reduced to a similar degree by both drugs. Despite similar reductions of MAP and renal ET-1 and ANG II levels aliskiren appears to be more effective than losartan, at the doses used, in reducing albuminuria in heterozygous hypertensive Ren-2 rats.

Topics: Albuminuria; Amides; Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Animals; Antihypertensive Agents; Blood Pressure; Disease Models, Animal; Down-Regulation; Endothelin-1; Enzyme-Linked Immunosorbent Assay; Fumarates; Hypertension; Kidney; Losartan; Male; Mice; Pilot Projects; Radioimmunoassay; Rats; Rats, Transgenic; Renin; Time Factors

Chronic inflammation has been implicated in the pathology of hypertension; however, the role for specific cytokines remains unclear. We tested whether tumor necrosis factor-α blockade with etanercept (Etan) reduces mean arterial pressure in a female mouse model of systemic lupus erythematosus (SLE). SLE is a chronic inflammatory disorder with prevalent hypertension. Thirty-week-old SLE (NZBWF1) and control mice (NZW/LacJ) received Etan (0.8 mg/kg SC weekly) for 4 weeks or vehicle. Mean arterial pressure (in millimeters of mercury) was increased in SLE mice (150±5 versus 113±5 in controls; P<0.05) and was lower in Etan-treated SLE mice (132±3) but not controls (117±5). Albuminuria (in micrograms per milligram of creatinine) was elevated in SLE mice (28 742±9032 versus 1075±883; P<0.05) and was lower in Etan-treated SLE mice (8154±3899) but not control animals (783±226). Glomerulosclerosis (in percentage of glomeruli) was evident in SLE mice (2.5±1.6 versus 0.0±0.0 in controls; P<0.05) and was ameliorated in Etan-treated SLE mice (0.1±0.1). Renal cortex CD68(+) cell staining (in percentage of area) was elevated in SLE mice (4.75±0.80 versus 0.79±0.12 in controls; P<0.05) and was lower in Etan-treated SLE mice (2.28±0.32) but not controls (1.43±0.25). Renal cortex NADPH oxidase activity (relative light units per milligram of protein) was higher in SLE mice compared with controls (10 718±1276 versus 7584±229; P<0.05) and lowered in Etan-treated SLE mice (6645±490). Renal cortex nuclear factor κB (phosphorylated and nonphosphorylated) was increased in SLE mice compared with controls and lower in Etan-treated SLE mice. These data suggest that TNF-α mechanistically contributes to the development of hypertension in a chronic inflammatory disease through increased renal nuclear factor κB, oxidative stress, and inflammation.

Topics: Albuminuria; Animals; Anti-Inflammatory Agents, Non-Steroidal; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Blood Pressure; Body Weight; Chemokine CCL2; Creatinine; Disease Models, Animal; Endothelin-1; Etanercept; Female; Glomerulosclerosis, Focal Segmental; Hypertension; Immunoglobulin G; Kidney; Kidney Cortex; Lupus Erythematosus, Systemic; Mice; Mice, Inbred Strains; NADPH Oxidases; NF-kappa B; Receptors, Tumor Necrosis Factor; Tumor Necrosis Factor-alpha

The aim of the study was to investigate endothelial function in patients with arterial hypertension and impaired uric acid metabolism in comparison with patients having arterial hypertension and normal uric acid metabolism. 46 patients aged 32-56 yr with grade I-II AH were included in the study. A group of 36 patients (27 male, 9 female) presented with AH and impaired uric acid metabolism (hyperuricemia), the control group included 10 patients with AH and unaffected uric acid metabolism. Inclusion criteria in the two groups were identical. Endothelial dysfunction was documented in all patients and confirmed by increased levels of serum endothelin-1 and microalbuminuria, qualitative and quantitative changes in the intima-media complex and its thickening. These changes were much more pronounced in patients with hyperuricemia It is concluded that impaired uric acid metabolism in patients with AH leads to rapid onset and progression of endothelial dysfunction. This fact should be taken into consideration by doctors practicing antihypertensive treatment and for the evaluation of cardiovascular risks.

Topics: Adult; Albuminuria; Antihypertensive Agents; Endothelin-1; Endothelium, Vascular; Female; Humans; Hypertension; Hyperuricemia; Male; Middle Aged; Risk Factors; Tunica Intima; Uric Acid

Women with systemic lupus erythematosus (SLE) exhibit a high prevalence of hypertension and renal injury. Rosiglitazone (Rosi), a peroxisome proliferator activator receptor gamma (PPARgamma) agonist, has renal protective and antihypertensive effects. We tested whether Rosi ameliorates hypertension and renal injury in a female mouse model of SLE (NZBWF1). Thirty-week-old SLE and control (NZW/LacJ) mice (n > or = 6/group) were fed Rosi (5 mg.kg(-1).day(-1) in standard chow) or standard chow for 4 wk. SLE mice had increased blood pressure (BP in mmHg) compared with controls (139 +/- 4 vs. 111 +/- 4, P < 0.05). Rosi treatment lowered BP in SLE mice (127 +/- 4, P < 0.05) but not in controls (111 +/- 4). Urinary albumin (mug/mg creatinine) was increased in SLE mice compared with controls (12,396 +/- 6,525 vs. 50 +/- 6) and reduced with Rosi treatment (148 +/- 117). Glomerulosclerosis (% of glomeruli with sclerosis) was reduced in Rosi-treated SLE mice (4.2 +/- 1.6 vs. 0.4 +/- 0.3, P < 0.05). Renal monocyte/macrophage numbers (cell number/1,320 points counted) were reduced in SLE mice treated with Rosi (32.6 +/- 11.0 vs. 10.6 +/- 3.6, P < 0.05) but unchanged in controls (3.7 +/- 1.6 vs. 3.7 +/- 2.0). Renal osteopontin expression, a cytokine-regulating macrophage recruitment, was reduced in Rosi-treated SLE mice. Urinary endothelin (in pg/mg creatinine) was increased in SLE mice compared with controls (1.9 +/- 0.59 vs. 0.6 +/- 0.04, P < 0.05) and reduced in SLE mice treated with Rosi (0.8 +/- 0.11, P < 0.05). PPARgamma protein expression in the renal cortex was significantly lower in SLE mice compared with controls and was unaffected by Rosi. These data suggest that Rosi may be an important therapeutic option for the treatment of SLE hypertension and renal injury.

Topics: Albuminuria; Animals; Antihypertensive Agents; Blood Pressure; Chemokine CCL2; Disease Models, Animal; Endothelin-1; Female; Hypertension; Kidney; Kidney Diseases; Lupus Erythematosus, Systemic; Macrophages; Mice; Monocytes; Osteopontin; PPAR gamma; RNA, Messenger; Rosiglitazone; Thiazolidinediones

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

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

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

The subjects of the study were 29 men (mean age 37.7+/-9.3 years) suffering from abdominal obesity without carbohydrate exchange disturbances or signs of chronic renal diseases. The results of the study show that the surplus of leptin, typical of obese patients, leads to the development of intrarenal vascular endothelial dysfunction, which is manifested by microalbuminuria, the growth of endothelin-1 serum level, and endothelium-dependent vasodilatation impairment, leading to unfavorable changes in renal filtration. Administration of angiotensin II receptor blockers results in the elimination of microalbuminuria and the recovery of endothelium-dependent vasodilatation in obese patients.

Topics: Adult; Albuminuria; Angiotensin II Type 1 Receptor Blockers; Endothelin-1; Endothelium, Vascular; Humans; Male; Middle Aged; Obesity; Prognosis; Renal Circulation; Vasodilation

Sickle cell disease (SCD) affects the kidney by acute mechanisms as well as by insidious renal medullary/papillary necrosis, resulting in tubular defects, which increase the risk of dehydration and subsequent sickle crisis. Hypoxia has been reported to stimulate endothelin-1 (ET-1) synthesis by endothelial cells and also in the renal tubule.. This case-control study measured ET-1 in urine as a marker of its renal synthesis in asymptomatic SCD patients. Baseline plasma and urinary ET-1 levels were measured and followed during a water deprivation study and a subsequent administration of desmopressin.. Urine and plasma levels of ET-1 were elevated in patients with SCD, compared with carefully matched African-French and African controls, and urine ET-1 excretion was associated with a marked urine-concentrating defect. Moreover, urinary ET-1 output was correlated with microalbuminuria in SCD patients.. ET-1 is known to antagonize the tubular effects of vasopressin and to promote renal scarring; increased renal production of ET-1 could produce nephrogenic diabetes insipidus and dehydration in SCD patients through a combination of fibrosis and functional resistance to vasopressin. This study provides a rationale for trials with endothelin receptor antagonists in sickle cell disease nephropathy.

Topics: Adult; Albuminuria; Anemia, Sickle Cell; Biomarkers; Case-Control Studies; Diabetes Insipidus, Nephrogenic; Disease Progression; Endothelin-1; Female; Humans; Kidney Tubules; Male; Radioimmunoassay; Severity of Illness Index

There is little information whether cardiac capillary supply is deranged in diabetes. Hyperglycaemia is a potent stimulus for endothelin-1 (ET-1) production. We therefore hypothesised that increased ET-1 production in Streptozotocin-induced Type 1 diabetes causes abnormalities of cardiac capillaries and the aorta. To this end we compared the effects of an ET receptor A blocker (ETA-RB) with that of an ACE-inhibitor (ACE-i) or their combination in rats with Streptozotocin (STZ) diabetes.. Sprague Dawley rats were injected with 65 mg STZ i.v. and subsequently developed diabetes. Rats were left untreated or received daily either the ACE-i Trandolapril, the ETA-RB Darusentan or a combination of both. After 6 months the experiment was terminated and the heart and the aorta were investigated using quantitative morphological techniques.. ACE-i but not ETA-RB lowered blood pressure in STZ Type 1 diabetic rats. Capillary length density was lower in untreated STZ diabetic rats (2932+/-128 mm/mm3) compared to non-diabetic control rats (3410+/-252 mm/mm3). Treatment with ACE-i (3568+/-431 mm/mm3), but not with ETA-RB (2893+/-192 mm/mm3), prevented the decrease in capillary supply. Volume density of the myocardial interstitium was higher in untreated STZ diabetic rats (0.86+/-0.04%) compared to non-diabetic control rats (0.36+/-0.06%). In all three intervention groups the values were lower (ACE-i: 0.53+/-0.05%, ETA-RB: 0.7+/-0.08% and combination: 0.69+/-0.1).. Our study identifies a capillary defect of the heart in STZ diabetes, i.e. decreased capillary supply. This abnormality was reversed by ACE-i, but not by ETA-R blockade. A similar trend, although not complete normalisation, was seen in cardiac fibrosis.

Topics: Albuminuria; Angiotensin-Converting Enzyme Inhibitors; Animals; Aorta, Thoracic; Arterioles; Blood Glucose; Blood Pressure; Body Weight; Cardiovascular Diseases; Collagen Type IV; Coronary Vessels; Diabetes Mellitus, Experimental; Endothelin A Receptor Antagonists; Endothelin-1; Fibrosis; Gene Expression; Heart; Immunohistochemistry; In Situ Hybridization; Indoles; Male; Myocardium; Phenylpropionates; Pyrimidines; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A; Transforming Growth Factor beta

Two endothelium-derived factors, endothelin (ET), a vasoconstrictor, and vascular endothelial growth factor (VEGF), an angiogenic factor are thought to be involved in the pathogenesis of diabetic vascular complications. The aim of this study was to determine the effects of an angiotensin II type I (AT-1) receptor antagonist and an ACE inhibitor on the pathogenesis of VEGF and ET-1-mediated kidney disease in STZ-induced diabetic rats. Two days after STZ administration, diabetic rats were treated for 8 weeks with enalapril maleate, an ACE inhibitor, candesartan cilexetil, an AT-1 receptor antagonist, or saline. Urinary albumin and N-acetyl beta-D glucosaminidase (NAG) excretion as well as the VEGF protein content in the kidney were all found to be elevated in diabetic rats. Administration of enalapril maleate or candesartan cilexetil decreased the level of microalbuminuria and NAG excretion in diabetic rats. Administration of enalapril maleate also suppressed the elevated renal VEGF protein content in these animals while candesartan cilexetil treatment had no effect. Serum ET-1 and VEGF levels were unchanged by these treatments. These data support a role for AT-1 receptor antagonists and ACE inhibitors in the prevention of diabetic nephropathy, and suggest that the former may work by reducing renal VEGF levels.

Topics: Albuminuria; Analysis of Variance; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Glucose; Blotting, Western; Diabetes Mellitus, Experimental; Diabetic Angiopathies; Diabetic Nephropathies; Disease Progression; Enalapril; Endothelin-1; Kidney; Male; Rats; Rats, Wistar; Streptozocin; Tetrazoles; Vascular Endothelial Growth Factor A

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

Hypokalemia causes renal tubulointerstitial injury with an elevation in renal endothelin-1 (ET-1). It was hypothesized that hypokalemic tubulointerstitial injury is ameliorated by the blockade of ET-A receptors (ETA), whereas ET-B receptor (ETB) antagonism may exacerbate the injury, because ETB is thought to mediate vasodilation. Rats were fed a K(+)-deficient diet alone (LC) or with an ETA-selective antagonist ABT-627 (LA) or an ETB-selective antagonist A-192621 (LB) for 8 wk. Control rats were on a normal K(+) diet alone or with the ETA-selective or ETB-selective antagonists. The severity of hypokalemia was not significantly different among LA, LB, and LC. LC developed tubulointerstitial injury with an elevation of renal preproET-1 mRNA level. There was an increase in tubular osteopontin expression, macrophage infiltration, collagen accumulation, and tubular cell hyperplasia. ETA blockade significantly ameliorated all parameters for renal injury in the cortex without suppressing local ET-1 and ETA expression. By contrast, ETB blockade significantly reduced local ET-1 and ETA expression and improved the injury to a similar extent in the cortex. In the medulla, ETA or ETB blockade only partially blocked renal injury. ETA blockade did not affect BP in normokalemic or hypokalemic rats. ETB blockade induced a BP elevation with a decrease in urinary Na(+) excretion in normokalemic but not in hypokalemic rats. These results indicate that ET-1 can mediate hypokalemic renal injury in two different ways: by directly stimulating ETA and by locally promoting endogenous ET-1 production via ETB. Thus, ETA as well as ETB blockade may be renoprotective in hypokalemic nephropathy.

Topics: Albuminuria; Animals; Atrasentan; Endothelin Receptor Antagonists; Endothelin-1; Hypertension; Hypertrophy; Hypokalemia; Kidney; Kidney Diseases; Kidney Tubules; Male; Potassium; Proteinuria; Pyrrolidines; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A; Receptor, Endothelin B

We tested the effect of selective endothelin ET(A) receptor blockade on the development renal damage in the Sabra rat model of genetic salt-sensitivity. Animals from the salt-sensitive (SBH/y) and salt-resistant strains (SBN/y) were either salt-loaded with deoxycorticosterone acetate and salt (DOCA) or fed a normal diet. Additional salt-loaded groups were also treated with the selective ET(A) antagonist darusentan (DA). Salt-loading in SBH/y increased systolic blood pressure by 75 mm Hg and urinary albumin excretion 23-fold (P<0.0001). Darusentan attenuated the rise of systolic blood pressure (50%) and urinary albumin excretion (63%, P<0.01, respectively). Salt-loading in SBH/y was associated with significant increased osteopontin mRNA expression as well as glomerulosclerosis and tubulointerstitial damage in the kidney (P<0.05, respectively). This was either significantly reduced or normalized by darusentan (P<0.05, respectively). Thus, darusentan confers a significant renal protection in the Sabra model of salt-sensitive hypertension.

Topics: Albuminuria; Animals; Body Weight; Desoxycorticosterone; Disease Models, Animal; Endothelin A Receptor Antagonists; Endothelin-1; Hypertension; Kidney; Kidney Diseases; Male; Organ Size; Osteopontin; Phenylpropionates; Pyrimidines; Rats; Rats, Inbred Strains; Receptor, Endothelin A; Receptor, Endothelin B; RNA, Messenger; Sialoglycoproteins; Sodium; Sodium Chloride, Dietary

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

A decreased GFR in the range of mild renal insufficiency and an increased urinary albumin excretion (UAE) rate in the range of microalbuminuria are important cardiovascular risk factors. Endothelin-1 (ET-1) has been suggested to be a major disease promoting factor in renal disease. The role of the ET-1 gene locus (EDN1) for renal function in the general nondiabetic population was evaluated. To explore the overall relevance of EDN1, two suitable single-nucleotide polymorphisms, EDN1 K198N and EDN1 T-1370G, were selected, and haplotype analysis was performed. Determined were genotypes in 7291 nondiabetic subjects from the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study. Genetic analysis was related to UAE and GFR as continuous variables and to microalbuminuria and diminished filtration as dichotomous traits. In a logistic regression analysis, no significant higher risk for increased UAE, microalbuminuria, decreased GFR, or diminished filtration could be observed for either single-nucleotide polymorphism separately. Haplotype analysis revealed that individuals with the homozygous G-N haplotype (compound EDN1 -1370GG/198NN genotype) have a lower GFR than the remaining subjects (P < 0.05) and exhibit a significant higher risk for the presence of a diminished filtration (relative risk, 2.4; 95% confidence interval, 1.07 to 5.33; P < 0.05). Further analysis demonstrated no association between this haplotype and UAE or plasma ET-1 levels. Although a functional relevance of the EDN1 G-N haplotype itself remains unclear, the data demonstrate that genetic variation at the EDN1 locus has a significant effect on glomerular filtration but not on UAE in the general nondiabetic population.

Topics: Adult; Aged; Albuminuria; Case-Control Studies; Cohort Studies; Endothelin-1; Female; Glomerular Filtration Rate; Haplotypes; Humans; Kidney Failure, Chronic; Male; Middle Aged; Polymorphism, Single Nucleotide; Risk Factors

Cigarette smoking increases the risk of progression of diabetic and non-diabetic renal diseases. The mechanisms underlying the adverse effects of smoking are largely unknown. We examined the subtotally nephrectomized rat (i) to investigate whether components of cigarette smoke dissolved in acetone (cigarette smoke condensate) aggravate structural renal damage and (ii) to establish whether this provides an animal model that can be used to investigate potential pathomechanisms of cigarette smoke-induced renal damage. Since nicotine activates the sympathetic nerve system in humans, we investigated whether interference with this system modulates the effects of cigarette smoke condensate on the damaged kidney.. One group of Sprague-Dawley rats was subtotally nephrectomized (SNX). Acetone (SNX + solvent) or cigarette smoke condensate (SNX + cigarette) was applied daily to the oral mucosa. Another group of Sprague-Dawley rats was sham-operated and received the same treatments (sham + solvent, sham + cigarette). To investigate whether increased activity of the sympathetic nerve system is involved, the remnant kidney was denervated by microsurgical technique in one SNX + cigarette group. The control group for this intervention was a solvent-treated SNX group with denervated remnant kidney. Blood pressure (BP) was measured weekly by tail plethysmography. The experiment was terminated after 12 weeks. Structural renal damage was assessed by morphometric techniques (indices of glomerulosclerosis, tubulointerstitial and vascular damage) and urinary albumin and endothelin-1 excretion were measured.. Indices of structural renal damage were increased in all SNX-groups. Treatment with cigarette smoke condensate further increased the indices of glomerulosclerosis and tubulointerstitial damage in SNX, but not sham-operated rats. This increase was completely prevented by renal denervation. No differences in systemic blood pressure were observed in the different SNX groups. Urinary albumin excretion went in parallel with the indices of glomerulosclerosis and tubulointerstitial damage and urinary endothelin-1 excretion was significantly increased in SNX + cigarette animals.. These findings document that acetone soluble components in cigarette smoke aggravate glomerulosclerosis and tubulointerstitial damage in the renal ablation model. Renal injury induced by cigarette smoke condensate in this model is reversed by renal denervation. We conclude that cigarette smoke-induced renal damage is due, at least in part, to activation of the sympathetic nerve system.

Topics: Albuminuria; Animals; Cholesterol; Cotinine; Creatinine; Endothelin-1; Glomerulosclerosis, Focal Segmental; Kidney; Male; Nephrectomy; Nicotiana; Rats; Rats, Sprague-Dawley; Smoke; Sympathetic Nervous System; Triglycerides; Urea

It has been reported that improvement of metabolic control by intensified insulin therapy in patients with Type I (insulin-dependent) diabetes mellitus is associated with alterations in ocular blood flow. We hypothesized that these changes in ocular blood flow could be associated with alterations of plasma insulin, glucose or endothelin concentration.. In 16 patients with Type I diabetes ocular haemodynamic parameters were assessed daily during the first 5 days of institution of intensified insulin therapy and plasma concentrations of glucose, insulin, and endothelin-1 plasma were measured. Retinal white blood cell flux was estimated with the blue field entoptic technique. Pulsatile choroidal blood flow was assessed by laser interferometric measurement of fundus pulsation amplitude.. Retinal white blood cell flux ( p=0.0015) and ocular fundus pulsation amplitude ( p<0.001) increased during institution of strict metabolic control. Changes in ocular haemodynamic variables were inversely correlated with concentrations of plasma ET-1, but not with that of insulin or glucose.. These data indicate that institution of improved metabolic status is paralleled by rapid changes in the production of ET-1, which could in turn affect ocular perfusion.

Topics: Adult; Albuminuria; Blood Glucose; Blood Pressure; Cholesterol, HDL; Diabetes Mellitus, Type 1; Diabetic Retinopathy; Dose-Response Relationship, Drug; Endothelin-1; Female; Hemodynamics; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Pulse; Retinal Vessels; Triglycerides

It is unclear why a subgroup of patients with essential hypertension develop salt-sensitive hypertension with progression of target organ damage over time. We evaluated the role of the renal endothelin (ET) system in the stroke-prone spontaneously hypertensive rat (SHRSP) model of salt-sensitive spontaneous hypertension (SS-SH) compared with the spontaneously hypertensive rat (SHR) model of salt-resistant spontaneous hypertension (SR-SH). Both strains were studied after either sham-operation on a normal diet (Sham) or after unilateral nephrectomy and high NaCl loading (NX-NaCl) with 4% NaCl in diet for 6 weeks (n=10, respectively). Systolic blood pressure (SBP) increased only in SHRSP-NX-NaCl compared with SHRSP-Sham (250+/-6 versus 172+/-5 mm Hg, P:<0.0001). SBP remained unchanged in SHR-NX-NaCl compared with SHR-Sham. In SHRSP-NX-NaCl animals, urinary albumin and ET-1 excretion, renal ET-1 mRNA expression, glomerulosclerosis index, and tubulointerstitial damage index were elevated compared with SHRSP-Sham (P:<0.05, respectively), whereas no significant changes were found in SHR after NX-NaCl. Urinary sodium excretion (U(Na(+))) was significantly reduced by 38% in SHRSP-NX-NaCl compared with SHR-NX-NaCl (P:<0.005, respectively). SHR animals showed a similar increase in both renal ET(A) and ET(B) receptor densities after NX-NaCl (2.2-fold, P:<0.05). In contrast, SHRSP-NX-NaCl developed a significantly more pronounced increase in ET(A) compared with ET(B) binding (4.7-fold versus 2.4-fold, P:<0.05, compared with SHRSP-Sham, respectively), resulting in a significant 2.1-fold increase in ET(A)/ET(B) receptor ratio only in the SHRSP-NX-NaCl (P:<0.05). Thus, activation of the renal ET system together with an increased ET(A)/ET(B) receptor ratio may contribute to the development and progression of SS-SH.

Topics: Albuminuria; Animals; Aspartic Acid Endopeptidases; Binding, Competitive; Blood Pressure; Blotting, Northern; Body Weight; Endothelin-1; Endothelin-Converting Enzymes; Hypertension; Kidney; Kidney Diseases; Male; Metabolic Clearance Rate; Metalloendopeptidases; Nephrectomy; Organ Size; Proteinuria; Rats; Rats, Inbred SHR; Receptor, Endothelin A; Receptor, Endothelin B; Receptors, Endothelin; RNA, Messenger; Sodium; Sodium, Dietary; Urination

Recently, an endothelin (ET-1) with a potent vasoconstrictive activity and stimulative activity of vascular muscular cell growth was discovered and blood ET-1 levels were higher in diabetic patients than in healthy subjects, suggesting that high ET-1 levels assist development and progression of diabetic microangiography.. We examined renal function, and serum and tissue ET-1 levels in streptozotocin (STZ)-induced diabetic rats treated with a prostaglandin (PG) I(2) derivative to investigate the effect of PGI(2) in diabetic vascular disturbance.. Renal weight, urinary albumin, urinary N-acetyl-beta,D-glucosaminidase (NAG) and serum ET-1 levels increased in STZ-induced diabetic rats, and a tendency to increase in renal tissue ET-1 levels was observed. Furthermore, electron-microscopic findings in the kidneys showed mesangial cell proliferation and mesangial matrix expansion which might be caused by diabetic nephropathy. The PGI(2) derivative reduced urinary albumin and NAG levels in STZ-induced rats. It was considered, therefore, that the PGI(2) derivative is effective in diabetic nephropathy. As the PGI(2) derivative also reduced renal tissue ET-1 levels, improvement of diabetic nephropathy partially was considered to result from the reduction of renal tissue ET-1 levels.. In STZ-induced rats, increased serum ET-1 levels and a tendency to increase in renal tissue ET-1 levels were associated with increases in urinary albumin and NAG levels, and these levels were decreased by a PGI(2) derivative. These findings suggested that increased ET-1 concentrations assist development and progression of diabetic nephropathy, especially diabetic microangiopathy, and the PGI(2) derivative may be effective for inhibition of diabetic microangiopathy mediated by reduction of ET-1 concentrations.

Topics: Albuminuria; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Endothelin-1; Epoprostenol; Fasting; Hypoglycemic Agents; Kidney; Male; Microscopy, Electron; Organ Size; Rats

Previous evidence has demonstrated a relationship between growth factors and cardiovascular diseases. This study was aimed at evaluating levels of some endothelium-derived growth factors, and their relationship with microalbuminuria (MAU), in essential hypertension. Ninety-nine mild-moderate essential hypertensives (EH) and 25 healthy controls were studied. All patients underwent 24-h blood pressure monitoring, serum endothelin-1 (ET-1), basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF), and 24-h MAU assays. Later, EH were divided into two subsets consisting of microalbuminurics (MAU >11 microg/min) and nonmicroalbuminurics (MAU <11 microg/min). In microalbuminuric EH, circulating ET-1, bFGF, and PDGF were significantly higher than in nonmicroalbuminurics (P < .0001, P < .0001, P < .005, respectively) or in controls. In the group of 99 EH, significant positive correlations of MAU with both ET-1 and bFGF (r = 0.35, P < .001, and r = 0.34, P < .001, respectively) were found. ET-1 and bFGF correlated significantly (r = 0.31, P < .002). Circulating bFGF also correlated significantly with MAU in the microalbuminuric EH subset (r = 0.49, P < .01). Our results show that in microalbuminuric EH circulating levels of certain growth factors are increased. In human essential hypertension these factors are linked with MAU, an early cardiovascular and renal damage marker.

Topics: Adult; Albuminuria; Biomarkers; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Creatinine; Endothelin-1; Endothelium, Vascular; Enzyme-Linked Immunosorbent Assay; Female; Fibroblast Growth Factor 2; Humans; Hypertension; Male; Platelet-Derived Growth Factor; Spectrophotometry

Elevated urinary albumin excretion (UAE) is a predictor of cardiovascular disease, and one possible explanation is that elevated UAE reflects a generalized vascular dysfunction. The present study tests whether the plasma concentrations of the two main endothelial vasoactive substances (nitric oxide and endothelin-1 [ET-1]) are changed in clinically healthy subjects with elevated UAE (>6.6 microg/ min-the 90th percentile in the background population) and to test associations between these concentrations and systemic blood pressure. Twenty-seven subjects with elevated UAE were compared with 46 matched controls with normoalbuminuria. Plasma concentration of ET-1 was measured using an ELISA method and plasma concentration of nitrate/nitrite using a photometric method. Twenty-four-hour blood pressure was measured using a portable recorder (TM-2421). No significant differences in the concentrations of nitrate/nitrite and ET-1 were found between the groups, e.g. 21 (10-105) vs. 18 (11 -152) (p=0.33) and 0.98 (0.58 1.95) vs. 1.10 (0.54 -1.50) (p = 0.27), respectively. However, plasma nitrate/nitrite was significantly positively correlated to systolic and diastolic blood pressure in subjects with normoalbuminuria but not in subjects with elevated UAE. In contrast, plasma ET-1 concentration was significantly positively correlated to systolic blood pressure only in subjects with elevated UAE. In conclusion, elevated UAE is not associated with changed plasma concentrations of endothelial vasoactive substances in clinically healthy subjects. However, nitrate/nitrite is positively correlated to BP only in subjects with normoalbuminuria, and ET-1 is positively correlated to BP only in subjects with elevated UAE.

Topics: Aged; Albuminuria; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Endothelin-1; Endothelium, Vascular; Female; Humans; Longitudinal Studies; Male; Middle Aged; Myocardial Ischemia; Nitrates; Nitric Oxide; Nitrites; Reference Values; Risk Factors

Topics: Adolescent; Adult; Aged; Albuminuria; Child; Child, Preschool; Endothelin-1; Female; Humans; Infant; Male; Pseudoxanthoma Elasticum; von Willebrand Factor

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

To observe the effect of Tangweikang capsule (TWKC) in treating diabetic nephropathy (DN).. The 119 patients enrolled were divided into 2 groups, 78 patients in the TWKC group treated with TWKC and 41 patients in the control group treated with Captopril. The changes of symptom score, urinary microprotein series (urinary albumin excretion rate, Tamm-horsfall protein and beta 2-microglobulin), blood glucose, kidney function, blood lipid, angiotensin I (A I) and II (A II), atrial natriuretic polypeptide (ANP), thromboxane B2(TXB2), 6-keto-prostaglandin F1 alpha, endothelin 1 (ET-1) and collagen IV in patients after treatment were observed.. The total effective rate in the TWKC group was 84.62%, which was superior to that in the control group (70.73%, P < 0.05). TWKC also showed better effects in improving clinical symptoms, lowering blood glucose, urinary microprotein series, blood lipid, A I, A II, ANP, ET-1 and collagen IV, ameliorating kidney function, and adjusting dynamic equilibrium of thromboxane-prostacyclin system, as compared with the control group (P < 0.05 or P < 0.01).. TWKC could lower the levels of blood glucose and lipid, improve the glucose and lipid metabolism, regulate the microcirculation, ameliorate the degree of kidney damage, therefore, it showed a better effect in treating diabetic nephropathy.

Topics: Adult; Aged; Albuminuria; beta 2-Microglobulin; Capsules; Collagen; Diabetic Nephropathies; Drugs, Chinese Herbal; Endothelin-1; Female; Humans; Male; Middle Aged; Phytotherapy

Chronic nephropathies are associated with enhanced renal synthesis of endothelin (ET)-1. A recent study demonstrated that an ET(A) receptor antagonist given to diabetic rats at the moment of disease induction prevented the development of renal injury. Here we investigated whether an unselective ET(A)/ET(B) receptor antagonist, PD 142,893, was renoprotective when given to streptozotocin diabetic rats when animals were already proteinuric. The effect of PD 142,893 was compared with that of an ACE inhibitor, lisinopril, known to retard progressive renal disease in experimental and human diabetes. PD 142,893 normalized systemic blood pressure, reduced urinary protein and albumin excretion, and ameliorated renal blood flow in diabetic rats, but it did not affect such parameters in control rats. Lisinopril had a renoprotective effect comparable to PD 142,893, although lisinopril controlled systemic blood pressure better. Northern blot analysis of ET-1 mRNA revealed upregulation of ET-1 gene in the diabetic kidney. Similar results were obtained by in situ hybridization in glomeruli and tubuli of diabetic rats. Both treatments remarkably attenuated exaggerated renal ET-1 gene expression. These data suggest that ET-1 is a contributory mediator of kidney damage in diabetes and indicate that ET receptor antagonists may represent a new therapeutic mean for treatment of progressive diabetic nephropathy.

Topics: Albuminuria; Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Pressure; Cohort Studies; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Dose-Response Relationship, Drug; Endothelin Receptor Antagonists; Endothelin-1; Follow-Up Studies; In Situ Hybridization; Kidney; Lisinopril; Male; Oligopeptides; Pilot Projects; Proteinuria; Rats; Rats, Sprague-Dawley; RNA, Messenger; Time Factors

An activated renal endothelin (ET) system is implicated in the pathogenesis of renal fibrosis, as recently shown in ET-1 transgenic mice. Because progressive renal fibrosis is also a major finding in diabetic nephropathy, we analyzed the activity of the renal ET system in rats with streptozotocin-induced diabetes mellitus and the effect of blocking the ETA receptor, using the orally active ETA antagonist LU 135252. The effects of long-term treatment with LU 135252 were compared with those of an ACE inhibitor. Plasma and urinary ET-1 concentrations were measured. Progression of diabetic nephropathy was analyzed by measuring urinary albumin and protein excretion. Urinary ET-1 excretion was significantly elevated as early as 7 days after induction of diabetes and increased further. The daily urine volume was significantly correlated with urine ET-1 excretion. Treatment with LU 135252 significantly decreased the ET-1 excretion by more than 50%, whereas ACE inhibition resulted only in a mild decrease. Albumin excretion was significantly decreased after ACE inhibition, whereas ETA inhibition resulted in a nonsignificant decrease. Urinary ET and albumin excretion probably reflect independent mechanisms of renal damage in diabetes.

Topics: Albuminuria; Angiotensin-Converting Enzyme Inhibitors; Animals; Diabetes Mellitus, Experimental; Endothelin Receptor Antagonists; Endothelin-1; Endothelins; Kidney; Kidney Function Tests; Mice; Phenylpropionates; Proteinuria; Pyrimidines; Rats; Rats, Wistar; Receptor, Endothelin A

The present study was performed to compare circulating levels of tumour necrosis factor-alpha (TNFalpha) and plasma endothelin 1 (ET-1), of hypertensive patients with or without renal failure and with those of normotensive healthy subjects. The study population consisted of 21 healthy normotensive subjects and 22 hypertensive patients, 11 with essential hypertension, and 11 with hypertension and chronic renal failure (CRF). Plasma ET-1 levels, serum TNFalpha and creatinine, creatinine clearance, 24-h urinary albumin excretion (UAE) were assayed, and 24-h blood pressure monitoring was obtained in all subjects. Office blood pressure was similar between hypertensive patients with and without CRF. However, 24-h blood pressure was greater in patients with CRF than in those with essential hypertension and normal renal function. Patients with hypertension manifested greater ET-1 levels than normotensive subjects (P < 0.01). Serum TNFalpha and ET-1 levels were higher in hypertensive patients with CRF than in patients with essential hypertension and normotensive subjects. In the 22 hypertensive patients, TNFalpha levels were negatively correlated with serum creatinine (r=0.60; P < 0.01), and ET-1 levels were positively correlated with UAE (r=0.47, P < 0.05). The present study has shown that hypertensive patients, and particularly those with renal insufficiency, manifest abnormal blood levels of ET-1 and TNFalpha. These factors could contribute to both cardiovascular and renal damage.

Topics: Adult; Albuminuria; Blood Pressure Monitoring, Ambulatory; Creatinine; Endothelin-1; Female; Humans; Hypertension; Hypertension, Renovascular; Kidney Failure, Chronic; Male; Middle Aged; Tumor Necrosis Factor-alpha

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

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

Our objective was to determine the effect of nitric oxide (NO) inhibition on renal synthesis of endothelin-1 (ET-1) in vivo.. Rats were administered 500 mg/l NG-nitro-L-arginine methyl ester (L-NAME) in their drinking water or its vehicle for 2 weeks (2W-L-NAME, n = 10; 2W-CONT, n = 10) or for 6 weeks (6W-L-NAME, n = 13; 6W-CONT, n = 11). We measured the levels of albumin, NO metabolites and ET-1 both in their blood and in 24 h urine samples, and determined the expression of preproET-1 messenger RNA in the renal cortex and the inner medulla. We also examined renal histology.. L-NAME administration for 6 weeks reduced NO metabolites both in serum (21.5 versus 3.66 nmol/ml in 6W-CONT) and in urine (5.72 versus 22.53 nmol/24 h in 6W-CONT), raised the systolic blood pressure (228 versus 162 mmHg in 6W-CONT), and the increased urinary excretion of albumin (24.29 +/- 11.66 versus 0.60 +/- 0.08 mg/day in 6W-CONT) and of ET-1 (112.0 +/- 38.3 versus 35.8 +/- 4.4 pg/day in 6W-CONT). There were no significant differences between the plasma levels of ET-1 in the control and L-NAME groups. Expression of preproET-1 messenger RNA increased in the renal cortex but not in the inner medulla in the 6W-L-NAME group. Bleeding and marked arteriolar narrowing were observed in the renal cortex of the 6W-L-NAME group.. Prolonged inhibition of NO synthesis increases urinary excretion of ET-1 and albumin without having any effect on plasma ET-1 levels. These results do not support the hypothesis that NO plays an inhibitory role in the regulation of ET-1 in the systemic circulation, although it is possible that such a role could exist in renal tissue. However, in view of the albuminuria, a more likely explanation is that increased urinary ET-1 is secondary to L-NAME-induced renal hyperfiltration injury.

Topics: Albuminuria; Animals; Blood Pressure; Endothelin-1; Enzyme Inhibitors; Kidney; Male; NG-Nitroarginine Methyl Ester; Nitrates; Nitric Oxide Synthase; Nitrites; Rats; Rats, Wistar

The present study was performed to characterize structurofunctional alterations of preglomerular vessels during chronic angiotensin II (Ang II)-induced hypertension (Ang II group: 400 ng x kg[-1] x min[-1], 10 days) and to assess the role of endothelin-1 in rats receiving Ang II and the mixed receptor antagonist bosentan (Ang II+B group: 30 mg x kg[-1] x d[-1], 10 days). Systolic blood pressure rose by 56+/-3 and 54+/-6 mm Hg in Ang II and Ang II+B rats, respectively. Albuminuria increased similarly in both Ang II-treated groups, reflecting glomerular barrier dysfunction. Preglomerular vessels were isolated after HCI maceration and comprised arcuate arteries and their branches, interlobular arteries (ILA), and afferent arterioles (AA). In the Ang II group, focal vascular lesions affected 36+/-6%, 20+/-5%, and 4+/-1% of arcuate arterial branches, ILA, and AA, respectively. They were characterized by 74% increased media thickness and accumulation of Sudan black-positive (SB+) lipid droplets, and media cell proliferation was documented through immunohistochemistry. The occurrence of SB+ lesions was strikingly reduced with bosentan. Autoregulatory responses (AR) were assessed along ILA and AA with the use of blood-perfused juxtamedullary nephron preparations. AR were elicited by raising blood perfusion pressure from 60 to 160 mm Hg and quantified through videomicroscopy as pressure-induced constrictions. AR were inhibited in Ang II-treated rats along ILA and AA; Ang II-induced AR changes were prevented by bosentan. Maximal relaxation induced by Mn2+ revealed equal basal tone in Ang II-treated, Ang II+B-treated, and control vessels. Chronic Ang II-induced hypertension is therefore associated with the development of SB+ lesions and selective impairment of AR in juxtamedullary nephrons. Endothelin-1 likely mediates the structurofunctional alterations of preglomerular vasculature during Ang II hypertension.

Topics: Albuminuria; Angiotensin II; Animals; Antihypertensive Agents; Blood Pressure; Bosentan; Endothelin-1; Hypertension; Kidney Glomerulus; Male; Microscopy, Video; Rats; Rats, Sprague-Dawley; Renal Circulation; Sulfonamides; Systole

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

Topics: Adult; Aged; Albuminuria; Endothelin-1; Female; Humans; Male; Pseudoxanthoma Elasticum; von Willebrand Factor

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