exenatide and Hyperglycemia

This systematic review investigated the effectiveness and safety of intensive insulin therapy (IIT), insulin secretagogues and sensitisers in burn patients. PubMed, Embase, clinicaltrials.gov and Cochrane central were searched from 1990 to 2016. Title/abstract screening, full-text review, critical appraisal and data extraction were carried out by two independent reviewers. Inclusion criteria were hospitalised burn patients, IIT, insulin sensitisers or secretagogues and the outcomes mortality, length of stay, resting energy expenditure, blood glucose, catabolism, or complications. We identified 594 potential studies of which 13 were included. Five studies investigated IIT in paediatric patients, 3 investigated IIT in adults and 5 investigated sensitisers or secretagogues. Glycaemic targets differed with age group - paediatric studies compared IIT to loose glycaemic control while adult studies compared IIT to more moderate control. Meta-analyses were limited by differences in outcome reporting, however mortality was increased in children by loose glycaemic control (OR=3.78, 95%CI 1.19-12.02) but not significantly affected in adults by moderate compared to tight control. Meta-analyses could not be performed for sensitisers or secretagogues. These findings support recommendations that moderate insulin administration (130-150mg/dL) is the prudent approach in burn patients. The evidence is relatively sparse and further research is warranted.

Topics: Burns; Dipeptidyl-Peptidase IV Inhibitors; Disease Management; Exenatide; Glipizide; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Insulin; Insulin Resistance; Metformin; Pioglitazone; Rosiglitazone; Secretagogues; Sulfonylurea Compounds

Topics: Animals; Body Weight; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hyperglycemia; Immunoglobulin Fc Fragments; Insulin; Liraglutide; Male; Obesity; Peptides; Recombinant Fusion Proteins

A large proportion of patients with type 1 diabetes do not reach their glycaemic target of glycated hemoglobin (HbA1c) <7.0% (53 mmol/mol) and, furthermore, an increasing number of patients with type 1 diabetes are overweight and obese. Treatment of type 1 diabetes is based on insulin therapy, which is associated with well-described and unfortunate adverse effects such as hypoglycaemia and increased body weight. Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are the focus of increasing interest as a possible adjunctive treatment to insulin in type 1 diabetes because of their glucagonostatic and extrapancreatic effects. So far, the focus has mainly been on the long-acting GLP-1RAs, but the risk-benefit ratio emerging from studies evaluating the effect of long-acting GLP-1RAs as adjunctive therapy to insulin therapy in patients with type 1 diabetes has been disappointing. This might be attributable to a lack of glucagonostatic effect of these long-acting GLP-1RAs in type 1 diabetes, alongside development of tachyphylaxis to GLP-1-induced retardation of gastric emptying. In contrast, the short-acting GLP-1RAs seem to have a preserved and sustained effect on glucagon secretion and gastric emptying in patients with type 1 diabetes, which could translate into effective lowering of postprandial glucose excursions; however, these observations regarding short-acting GLP-1RAs are all derived from small open-label trials and should thus be interpreted with caution. In the present paper we review the potential role of GLP-1RAs, in particular short-acting GLP-1RAs, as add-on to insulin in the treatment of type 1 diabetes.

Topics: Diabetes Mellitus, Type 1; Drug Resistance; Drug Therapy, Combination; Exenatide; Gastric Emptying; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Half-Life; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Insulin; Peptides; Venoms

This review examines the use of exenatide twice daily in managing changes in markers of cardiovascular risk in patients with type 2 diabetes.. Type 2 diabetes is a progressive metabolic disorder, which results from defects in insulin secretion and/or insulin action leading to chronic hyperglycaemia and associated cardiovascular complications. Despite the use of diet, exercise, oral antihyperglycaemic agents and insulin, the progressive nature of the condition means that the levels of the preventive and treatment measures would have to be increased and/or new therapies have to be developed in order to address the long term impact of type 2 diabetes. The advent of exenatide, a glucagon-like peptide-1 receptor agonist provides a useful basis for managing type 2 diabetes and related cardiovascular complications without the side effects of regular diabetes therapies. However, exenatide twice daily is often used in combination with other therapies, although the mechanism of exenatide in managing diabetes and and associated cardiovascular risks and complications remain complex and still evolving.. A range of databases including EBSCOhost online research database were used to access articles based on PICO (Population, Interventions, Comparative Interventions, Outcomes) framework and Boolean operators.. Eleven randomised controlled studies which met the inclusion criteria were selected for this review. Nine of the eleven studies showed significant decrease in body weight among participants in the exenatide group compared with placebo or control group while the other two studies did not report statistically significant differences in body weight. In adition, all the studies showed statistically significant decrease in glycated haemoglobin (HbA1c) in the exenatide group compared to controls except in one study. In the present review, the seven studies, which looked at the effect of exenatide twice daily on lipid profile, did not find any significant difference between the exenatide group and the control group except for High density lipoprotein-cholesterol in two of the studies. However, statistically significant decrease was observed between exenatide group and controls with respect to blood pressure (systolic and/or diastolic) in these studies.. It would appear that exenatide is more effective in reducing body weight in patients with type 2 diabetes when used in combination with metformin than when used alone or in combination with thiazolidinedione. The findings of this review would suggest that exenatide twice daily may be useful in managing cardiovascular risks and complications by reducing body weight, HbA1c and blood pressure.

Topics: Biomarkers; Body Weight; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Exenatide; Female; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Male; Middle Aged; Peptides; Risk Factors; Thiazolidinediones; Venoms

The increased prevalence of type 2 diabetes follows the increased prevalence of obesity. Both diseases share common pathophysiological pathways; obesity is in most cases the first step, whereas diabetes is the second one. Weight gain occurs during the treatment of diabetes with drugs causing endogenous or exogenous hyperinsulinemia. Insulin and sulfonylurea are making patients more obese and more insulin resistant. Glucagon-like peptide-1 receptor agonists (GLP-1 agonists) and sodium/glucose cotransporter 2 inhibitors (SGLT2 inhibitors) are antidiabetic drugs with weight loss property. GLP-1 agonists mimic an incretin action. They release insulin after a meal during hyperglycemia and suppress glucagon. The weight loss effect is a consequence of central action increased satiety. Some of GLP-1 agonists weight loss is a result of decelerated gastric emptying rate. SGLT2 inhibitors block sodium glucose cotransporter in proximal tubule brush border and produce glucose excretion with urinary loss. Urinary glucose leak results in calories and weight loss. Even a modest weight loss has positive outcome on metabolic features of diabetic patient; such drugs have important role in treatment of type 2 diabetic patients. However, there are some still unresolved questions. The weight loss they produce is modest. Those drugs are expensive and not available to many diabetic patients, they are significantly more expensive compared to "traditional" hypoglycemic drugs. The hypoglycemic endpoint of GLP-1 agonists and SGLT2 inhibitors often requires adding another antidiabetic drug. The most radical and most effective therapy of type 2 diabetes and obesity is bariatric surgery having significant number of diabetes remission.

Topics: Anti-Obesity Agents; Bariatric Surgery; Biological Transport; Clinical Trials as Topic; Comorbidity; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucose; Glycosuria; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Kidney Tubules, Proximal; Microvilli; Multicenter Studies as Topic; Obesity; Peptides; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Venoms; Weight Loss

GLP-1 receptors agonists have been a substantial change in treatment of type 2 diabetes mellitus, and its weekly administration has broken pre-established schemes. Daily exenatide is administered every 12 hours (BID) subcutaneously, while weekly exenatide is administered once a week. Both molecules share a common mechanism of action but have differential effects on basal and postprandial glucose. We review the major clinical trials with both exenatide BID and weekly exenatide. It can be concluded that exenatide BID shows a hypoglycemic effect similar to other treatments for type 2 DM but adding significant weight loss with low incidence of hypoglycemia. Weekly exenatide decreases HbA1c similar to liraglutide but larger than exenatide BID, both glargine and biphasic insulin, sitagliptin, and pioglitazone, maintaining weight loss and adding to gastrointestinal intolerance the induration at the injection site as a side effect.

Topics: Delayed-Action Preparations; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Administration Schedule; Exenatide; Female; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Incretins; Injections, Subcutaneous; Insulin; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Male; Metformin; Peptides; Pioglitazone; Receptors, Glucagon; Thiazolidinediones; Venoms; Weight Loss

Recent research has indicated that appetite-regulating hormones from the gut may have therapeutic potential. The incretin hormone, glucagon-like peptide-1 (GLP-1), appears to be involved in both peripheral and central pathways mediating satiation. Several studies have also indicated that GLP-1 levels and responses to meals may be altered in obese subjects. Clinical trial results have shown further that two GLP-1 receptor agonists (GLP-1 RAs), exenatide and liraglutide, which are approved for the treatment of hyperglycemia in patients with type 2 diabetes, also produce weight loss in overweight subjects without diabetes. Thus, GLP-1 RAs may provide a new option for pharmacological treatment of obesity.

Topics: Animals; Eating; Exenatide; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Liraglutide; Obesity; Peptides; Receptors, Glucagon; Satiation; Signal Transduction; Venoms; Weight Loss

The two classes of incretin-related therapies, dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1 RAs), have become important treatment options for patients with type 2 diabetes. Sitagliptin, saxagliptin, vildagliptin and linagliptin, the available DPP-4 inhibitors, are oral medications, whereas the GLP-1 RAs-twice-daily exenatide, once-weekly exenatide and once-daily liraglutide-are administered subcutaneously. By influencing levels of GLP-1 receptor stimulation, these medications lower plasma glucose levels in a glucose-dependent manner with low risk of hypoglycaemia, affecting postprandial plasma glucose more than most other anti-hyperglycaemic medications. Use of GLP-1 RAs has been shown to result in greater glycaemic improvements than DPP-4 inhibitors, probably because of higher levels of GLP-1 receptor activation. GLP-1 RAs can also produce significant weight loss and may reduce blood pressure and have beneficial effects on other cardiovascular risk factors. Although both classes are well tolerated, DPP-4 inhibitors may be associated with infections and headaches, whereas GLP-1 RAs are often associated with gastrointestinal disorders, primarily nausea. Pancreatitis has been reported with both DPP-4 inhibitors and GLP-1 RAs, but a causal relationship between use of incretin-based therapies and pancreatitis has not been established. In clinical trials, liraglutide has shown efficacy and tolerability and resulted in certain significant benefits when compared with exenatide and sitagliptin.

Topics: Administration, Oral; Blood Glucose; Blood Pressure; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Drug Administration Schedule; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Injections, Subcutaneous; Liraglutide; Male; Peptides; Randomized Controlled Trials as Topic; Risk Factors; Venoms; Weight Loss

Incretin-based therapies have a glucose-dependent mode of action that results in excellent glucose-lowering efficacy with very low risk of hypoglycaemia, and weight neutrality [dipeptidyl peptidase-4 (DPP-4) inhibitors] or weight loss [glucagon-like peptide-1 (GLP-1) receptor agonists], in people with type 2 diabetes mellitus (T2DM). Patient-reported outcomes (PROs) complement physician evaluations of efficacy and tolerability and offer insights into the subjective experience of using modern diabetes treatments. We conducted a systematic search of clinical trials of the GLP-1 receptor agonists liraglutide, exenatide and long-acting exenatide, one of which included the oral DPP-4 inhibitor sitagliptin as a comparator. No other PRO data for DPP-4 inhibitors were identified. This review summarizes PRO data from eight clinical trials, the majority of which used the Diabetes Treatment Satisfaction Questionnaire (DTSQ) and/or Impact of Weight on Quality of Life-Lite (IWQOL-Lite) to evaluate patient experience. People with T2DM were highly satisfied with modern incretin-based therapies compared with traditional therapies. Treatment satisfaction (including perceptions of convenience and flexibility) was high and generally higher with GLP-1 agonists in association with their greater glucose-lowering efficacy and tendency to facilitate weight loss. Weight-related quality of life (QoL) also improved in people using incretin therapies. The glycaemic improvements achieved with GLP-1 receptor agonists, coupled with the low incidence of hypoglycaemia and ability to cause weight loss, seemed to offset potential concern about injections. It is plausible that superior patient-reported benefits found in clinical trials may translate into improved, clinically meaningful, long-term outcomes through increased treatment acceptability. Long-term, prospective data are needed to ascertain whether this is the case in practice.

Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Drug Administration Schedule; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Injections, Subcutaneous; Liraglutide; Male; Medication Adherence; Patient Satisfaction; Peptides; Pyrazines; Self Care; Sitagliptin Phosphate; Surveys and Questionnaires; Treatment Outcome; Triazoles; Venoms; Weight Loss

Topics: Adenocarcinoma; Antiemetics; Antineoplastic Combined Chemotherapy Protocols; Combined Modality Therapy; Dexamethasone; Diabetes Mellitus, Type 2; Disease Management; Drug Resistance; Drug Therapy, Combination; Exenatide; Fluorouracil; Humans; Hyperglycemia; Hyperglycemic Hyperosmolar Nonketotic Coma; Hypoglycemic Agents; Insulin; Leucovorin; Male; Malnutrition; Metformin; Middle Aged; Nausea; Organoplatinum Compounds; Oxaliplatin; Palliative Care; Pancreatectomy; Pancreatic Neoplasms; Peptides; Sulfonylurea Compounds; Venoms

Incretin-based therapies, such as the injectable glucagon-like peptide-1 (GLP-1) receptor agonists and orally administered dipeptidyl peptidase-4 (DPP-4) inhibitors, have recently been introduced into clinical practice. At present, the GLP-1 receptor agonists need to be administered once or twice daily. Several once-weekly GLP-1 receptor agonists are in phase 3 development. This review examines the efficacy, safety and perspective for the future of the once-weekly GLP-1 receptor agonists: exenatide once weekly, taspoglutide, albiglutide, LY2189265 and CJC-1134-PC, and compared them to the currently available agonists, exenatide BID and liraglutide QD. A greater reduction in haemoglobin A1c (HbA1c) and fasting plasma glucose was found with the once-weekly GLP-1 receptor agonists compared with exenatide BID, while the effect on postprandial hyperglycaemia was modest with the once-weekly GLP-1 receptor agonist. The reduction in HbA1c was in most studies greater compared to oral antidiabetic drugs and insulin glargine. The reduction in weight did not differ between the short- and long-acting agonists. The gastrointestinal side effects were less with the once-weekly agonists compared with exenatide BID, except for taspoglutide. Antibodies seem to be most frequent with exenatide once weekly, while hypersensitivity has been described in few patients treated with taspoglutide. Injection site reactions differ among the long-acting GLP-1 receptor agonists and are observed more frequently than with exenatide BID and liraglutide. In humans, no signal has been found indicating an association between the once-weekly agonists and C-cell cancer. The cardiovascular safety, durability of glucose control and effect on weight will emerge from several ongoing major long-term trials. The once-weekly GLP-1 receptor analogues are promising candidates for the treatment of type 2 diabetes, although their efficacy may not be superior to once-daily analogue liraglutide.

Topics: Biomarkers; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Liraglutide; Male; Peptides; Receptors, Glucagon; Recombinant Fusion Proteins; Venoms

The increasing prevalence, variable pathogenesis, progressive natural history, and complications of type 2 diabetes emphasise the urgent need for new treatment strategies. Longacting (eg, once weekly) agonists of the glucagon-like-peptide-1 receptor are advanced in development, and they improve prandial insulin secretion, reduce excess glucagon production, and promote satiety. Trials of inhibitors of dipeptidyl peptidase 4, which enhance the effect of endogenous incretin hormones, are also nearing completion. Novel approaches to glycaemic regulation include use of inhibitors of the sodium-glucose cotransporter 2, which increase renal glucose elimination, and inhibitors of 11β-hydroxysteroid dehydrogenase 1, which reduce the glucocorticoid effects in liver and fat. Insulin-releasing glucokinase activators and pancreatic-G-protein-coupled fatty-acid-receptor agonists, glucagon-receptor antagonists, and metabolic inhibitors of hepatic glucose output are being assessed. Early proof of principle has been shown for compounds that enhance and partly mimic insulin action and replicate some effects of bariatric surgery.

Topics: 11-beta-Hydroxysteroid Dehydrogenase Type 1; Allylamine; Anticholesteremic Agents; Bariatric Surgery; Bile Acids and Salts; Cardiovascular System; Colesevelam Hydrochloride; Comorbidity; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glucokinase; Humans; Hyperglycemia; Hypoglycemic Agents; Indoles; Insulin; Insulin Resistance; Insulin-Secreting Cells; Liver; Obesity; Peptides; Randomized Controlled Trials as Topic; Receptors, Dopamine D2; Signal Transduction; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome; Venoms

Long-acting glucagon-like peptide-1 receptor agonists (LA-GLP-1RAs) may deliver additional therapeutic benefits over other available incretin-based therapies.. To pool results of randomized controlled trials comparing the efficacy and safety of maximum dose LA-GLP-1RAs (liraglutide, exenatide once weekly) with exenatide twice daily and dipeptidyl-peptidase-IV inhibitors in patients with type 2 diabetes.. We searched PubMed, Cochrane Central Register of Controlled Trials and Database of Systematic Reviews, EMBASE (all from inception-December 2010), and abstracts presented at the American Diabetes Association Scientific Sessions in 2009 and 2010 to identify English-language reports of studies of at least 24 weeks' duration. The primary endpoint was mean change in hemoglobin A(1c) (A1C) from baseline to study endpoint. Weighted mean differences or odds ratios and their 95% confidence intervals for each outcome relative to control were calculated as appropriate.. A1C was reduced favoring LA-GLP-1RAs compared with exenatide twice daily and sitagliptin (weighted mean difference [WMD] -0.47% [95% CI -0.69 to -0.25] and WMD -0.60% [95% CI -0.75 to -0.45], respectively). Odds ratios greater than 1 favored LA-GLP-1RAs for reaching the A1C target goal of less than 7%. Fasting plasma glucose (FPG) was reduced and favored the LA-GLP-1RA-based regimens. Exenatide demonstrated significantly greater reductions in postprandial glucose (PPG) after the morning and evening meals, compared with LA-GLP-1RAs. Body weight was reduced similarly between LA-GLP-1RAs and exenatide, but favored LA-GLP-1RAs in the sitagliptin comparator trials. LA-GLP-1RA therapy was not associated with severe hypoglycemia or acute pancreatitis. Compared with exenatide twice daily, vomiting was reduced significantly with LA-GLP-1RAs (OR 0.55; 95% CI 0.34 to 0.89); there was a trend toward decreased nausea (OR 0.58; 95% CI 0.32 to 1.06) and no difference in the incidence of diarrhea (OR 1.03; 95% CI 0.67 to 1.58).. Compared with other incretin-based therapies, LA-GLP-1RAs produce greater improvement in A1C and FPG. They provide lesser effect on PPG, similar reduction in body weight, and result in a potentially favorable adverse event profile compared with exenatide twice daily.

Topics: Delayed-Action Preparations; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Liraglutide; Male; Middle Aged; Peptides; Pyrazines; Randomized Controlled Trials as Topic; Receptors, Glucagon; Sitagliptin Phosphate; Triazoles; Venoms

Type 2 diabetes mellitus and comorbidities related to overweight/obesity are risk factors for the development of cardiovascular disease (CVD). In addition to insulin resistance and progressive beta-cell failure as key factors in the pathogenesis of type 2 diabetes mellitus, defects in the incretin system are now known to contribute as well. Lifestyle modifications including diet and exercise are often insufficient for reducing glucose and weight, and most patients with type 2 diabetes will require pharmacotherapy to treat their hyperglycemia. Goals of therapy should be to reduce blood glucose to as low as possible, for as long as possible, without weight gain and hypoglycemia, and correcting cardiovascular risk factors. Numerous antidiabetes medications lower blood glucose; however, many are associated with weight gain and do not address risk factors present for CVD. Newer pharmacotherapies include the glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 (DPP-4) inhibitors, and amylinomimetics. The GLP-1 receptor agonists and amylinomimetics reduce glucose while promoting weight loss and improving other cardiovascular risk factors with a low incidence of hypoglycemia. The DPP-4 inhibitors effectively lower glucose and are weight neutral.

Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Life Style; Liraglutide; Obesity; Overweight; Peptides; Receptors, Glucagon; Venoms; Weight Loss

Successful management of type 2 diabetes mellitus (T2DM) requires attention to additional conditions often associated with hyperglycemia including overweight or obesity, dyslipidemia and hypertension, as each has some relationship with microvascular or macrovascular complications. Because control of cardiovascular risk factors is as important as glucose control in T2DM, these risk factors need to be addressed, and it is critical that antidiabetes medications do not exacerbate these risk factors. A patient-centered approach to treatment in which clinicians maximize patient involvement in the selection of antidiabetes therapy may lead to increased adherence and improved clinical outcomes. The incretin hormones, which include glucagon-like peptide-1 (GLP-1), are involved in glucoregulation and have become an important focus of T2DM research and treatment. Incretin-based therapies, such as the glucagon-like peptide-1 receptor agonists and the dipeptidyl peptidase-IV inhibitors, have shown beneficial effects on hyperglycemia, weight, blood pressure and lipids with a low incidence of hypoglycemia.

Topics: Adamantane; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Liraglutide; Nitriles; Obesity; Patient Compliance; Peptides; Piperidines; Precision Medicine; Primary Health Care; Pyrazines; Pyrrolidines; Risk Factors; Sitagliptin Phosphate; Triazoles; Uracil; Venoms; Vildagliptin

To evaluate the emerging classes of antihyperglycemic agents that target the incretin pathway, including their therapeutic efficacy and side effect profiles, in order to help identify their place among the treatment options for patients with type 2 diabetes.. MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews were searched. Most evidence is level I and II.. Two classes of incretin agents are currently available: glucagonlike peptide 1 (GLP1) receptor agonists and dipeptidyl peptidase 4 (DPP4) inhibitors, both of which lower hyperglycemia considerably without increasing the risk of hypoglycemia. The GLP1 receptor agonists have a greater effect on patients' glycated hemoglobin A(1c) levels and cause sustained weight loss, whereas the DPP4 inhibitors are weight-neutral.. The GLP1 and DPP4 incretin agents, promising and versatile antihyperglycemic agents, are finding their way into the therapeutic algorithm for treating type 2 diabetes. They can be used in patients not adequately controlled by metformin monotherapy or as initial therapy in those for whom metformin is contraindicated.

Topics: Adult; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Evidence-Based Medicine; Exenatide; Glucagon-Like Peptide 1; Glucose; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Liraglutide; Peptides; Venoms

Diabetes mellitus affects 21 million Americans; an additional 41 million individuals in this country have impaired glucose tolerance. These individuals are at high risk for developing not only diabetes, but eventually dying from the cardiovascular complications associated with chronic exposure to hyperglycemia. Not only do patients with diabetes carry a 1.5- to 4.5-fold increased risk of cardiovascular mortality, any microvascular complications they develop such as retinopathy, neuropathy, and nephropathy can have a profoundly negative effect on their quality of life. Even mild hyperglycemia is associated with macrovascular disease. Similarly, hyperglycemia that occurs concurrently during an acute myocardial infarction or stroke is associated with worse outcomes. Therefore, evidence suggests that both chronic and acute hyperglycemia lead to higher morbidity and mortality. As people age, their 2-hour postchallenge blood glucose level typically increases, often independent of their fasting glucose level. At diagnosis, 25% of patients with type 2 diabetes have normal fasting glucose levels. The incidence of isolated impaired glucose tolerance is approximately 3 times greater than isolated impaired fasting glucose. Therefore, most patients with asymptomatic diabetes have isolated postchallenge hyperglycemia. A growing body of literature supports targeting postprandial hyperglycemia to lower glycosylated hemoglobin (A1C) levels and reduce microvascular and macrovascular complications associated with chronic hyperglycemia. This article will evaluate a typical patient case and strategies employed by the patient and health care provider.

Topics: Biomimetic Materials; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Family Practice; Hemoglobin A; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Injections, Subcutaneous; Male; Middle Aged; Patient Acceptance of Health Care; Peptides; Primary Health Care; Treatment Outcome; Venoms

Approximately two thirds of patients with type 2 diabetes mellitus (T2DM) are unable to reach the hemoglobin A(1c) target set by the American Diabetes Association (HbA(1c) <7.0%). Therefore, T2DM continues to be a major public health concern. Incretin mimetics and dipeptidyl peptidase IV inhibitors are medications that have the potential to improve patients' glycemic control, as well as to result in beneficial socioeconomic effects. Research suggests that significant benefits are to be gained from incretin mimetics and dipeptidyl peptidase IV inhibitors, either one used as monotherapy or used together as combination therapy. However, the benefits and risks of these agents need to be evaluated more thoroughly, with emphasis on such adverse effects as edema, hypoglycemia, and weight gain.

Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Drug Administration Schedule; Exenatide; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Liraglutide; Male; Peptides; Probability; Prognosis; Treatment Outcome; Venoms

Topics: Algorithms; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Peptides; Postprandial Period; Pyrazines; Risk Factors; Sitagliptin Phosphate; Triazoles; Venoms

Hyperglycemia in acute ischemic stroke reduces the efficacy of stroke thrombolysis and thrombectomy, with worse clinical outcomes. Insulin-based therapies are difficult to implement and may cause hypoglycemia. We investigated whether exenatide, a GLP-1 (glucagon-like peptide-1) receptor agonist, would improve stroke outcomes, and control poststroke hyperglycemia with minimal hypoglycemia.. The TEXAIS trial (Treatment With Exenatide in Acute Ischemic Stroke) was an international, multicenter, phase 2 prospective randomized clinical trial (PROBE [Prospective Randomized Open Blinded End-Point] design) enrolling adult patients with acute ischemic stroke ≤9 hours of stroke onset to receive exenatide (5 µg BID subcutaneous injection) or standard care for 5 days, or until hospital discharge (whichever sooner). The primary outcome (intention to treat) was the proportion of patients with ≥8-point improvement in National Institutes of Health Stroke Scale score (or National Institutes of Health Stroke Scale scores 0-1) at 7 days poststroke. Safety outcomes included death, episodes of hyperglycemia, hypoglycemia, and adverse event.. From April 2016 to June 2021, 350 patients were randomized (exenatide, n=177, standard care, n=173). Median age, 71 years (interquartile range, 62-79), median National Institutes of Health Stroke Scale score, 4 (interquartile range, 2-8). Planned recruitment (n=528) was stopped early due to COVID-19 disruptions and funding constraints. The primary outcome was achieved in 97 of 171 (56.7%) in the standard care group versus 104 of 170 (61.2%) in the exenatide group (adjusted odds ratio, 1.22 [95% CI, 0.79-1.88];. Treatment with exenatide did not reduce neurological impairment at 7 days in patients with acute ischemic stroke. Exenatide did significantly reduce the frequency of hyperglycemic events, without hypoglycemia, and was safe to use. Larger acute stroke trials using GLP-1 agonists such as exenatide should be considered.. URL: www.australianclinicaltrials.gov.au; Unique identifier: ACTRN12617000409370. URL: https://www.clinicaltrials.gov; Unique identifier: NCT03287076.

Topics: Adult; Aged; Exenatide; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemia; Ischemic Stroke; Prospective Studies; Stroke; Treatment Outcome

Hyperglycemia is a predictor for poor stroke outcome. Hyperglycemic stroke patients treated with thrombolysis have an increased risk of intracranial hemorrhage. Insulin is the gold standard for treating hyperglycemia but comes with a risk of hypoglycemia. Glucagon-like peptide-1 receptor agonists (GLP-1RA) are drugs used in type 2 diabetes that have a low risk of hypoglycemia and have been shown to exert neuroprotective effects. The primary objective was to determine whether prehospital administration of the GLP-1RA exenatide could lower plasma glucose in stroke patients. Secondary objective was to study tolerability and safety.. Randomized controlled trial comparing exenatide administrated prehospitally with a control group receiving standard care for hyperglycemia. Patients with Face Arm Speech Test ≥1 and glucose ≥8 mmol/L were randomized. Glucose was monitored for 24 hours. All adverse events were recorded.. Nineteen patients were randomized, eight received exenatide. An interim recruitment failure analysis with subsequent changes of the protocol was made. The study was stopped prematurely due to slow inclusion. No difference was observed in the main outcome of plasma glucose at 4 hours, control vs exenatide (mean, SD); 7.0 ± 1.9 vs 7.6 ± 1.6; P = .56). No major adverse events were reported.. We found no evidence that prehospital exenatide had effect on hyperglycemia. However, it was given without adverse events in this study with limited sample size that was prematurely stopped due to slow inclusion.

Topics: Aged; Aged, 80 and over; Blood Glucose; Exenatide; Female; Humans; Hyperglycemia; Hypoglycemic Agents; Male; Middle Aged; Stroke

Impaired glucose tolerance (IGT) in cystic fibrosis (CF) manifests as postprandial hyperglycaemia. Pancreatic enzyme supplementation reduces the latter; restoring incretin secretion and slowing gastric emptying. We aimed to determine the acute effect of exenatide on postprandial glycaemia in young people with CF and IGT. Six participants with CF and IGT were studied on 2 days, in a double-blind randomized crossover trial. After overnight fasting, they received exenatide 2.5 mcg or placebo (0.9% saline) subcutaneously 15 minutes before a pancake meal labelled with

Topics: Adolescent; Adult; Blood Glucose; Child; Cross-Over Studies; Cystic Fibrosis; Double-Blind Method; Exenatide; Female; Gastric Emptying; Glucose Intolerance; Humans; Hyperglycemia; Incretins; Male; Postprandial Period; Young Adult

To simplify administration of aqueous exenatide once weekly, which requires reconstitution, the exenatide microspheres have been reformulated in a ready-to-use autoinjector with a Miglyol diluent (exenatide QWS-AI). This study compared the efficacy and safety of exenatide QWS-AI with the first-in-class glucagon-like peptide-1 receptor agonist exenatide twice daily (BID).. This randomized, open-label, controlled study in patients with type 2 diabetes using diet and exercise or taking stable oral glucose-lowering medication randomized patients 3:2 to either exenatide QWS-AI (2 mg) or exenatide BID (10 μg) for 28 weeks. The primary outcome was the 28-week change in glycated haemoglobin (HbA1c). A subset of patients completed a standardized meal test for postprandial and pharmacokinetic assessments.. A total of 375 patients (mean HbA1c, 8.5% [69 mmol/mol]; body mass index, 33.2 kg/m. Exenatide QWS-AI was associated with a greater reduction in HbA1c, similar weight loss and a favorable gastrointestinal AE profile compared with exenatide BID.

Topics: Cardiovascular Diseases; Cohort Studies; Combined Modality Therapy; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Cardiomyopathies; Drug Administration Schedule; Exenatide; Female; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Incretins; Injections, Jet; Intention to Treat Analysis; Male; Middle Aged; Patient Dropouts; Peptides; Risk Factors; Severity of Illness Index; Suspensions; United States; Venoms

To compare the efficacy and safety of adding the glucagon-like peptide-1 receptor agonist exenatide once weekly (QW) 2 mg or placebo among patients with type 2 diabetes who were inadequately controlled despite titrated insulin glargine (IG) ± metformin.. This multicentre, double-blind study (ClinicalTrials.gov identifier: NCT02229383) randomized (1:1) patients with persistent hyperglycaemia after an 8-week titration phase (glycated haemoglobin [HbA1c] 7.0%-10.5% [53-91 mmol/mol]) to exenatide QW or placebo. The primary endpoint was HbA1c change from baseline to week 28. Secondary endpoints included body weight, 2-hour postprandial glucose, and mean daily IG dose.. Of 464 randomized patients (mean: age, 58 years; HbA1c, 8.5% [69 mmol/mol]; diabetes duration, 11.3 years), 91% completed 28 weeks. Exenatide QW + IG vs placebo + IG significantly reduced HbA1c (least-squares mean difference, -0.73% [-8.0 mmol/mol]; 95% confidence interval, -0.93%, -0.53% [-10.2, -5.8 mmol/mol]; P < .001; final HbA1c, 7.55% [59 mmol/mol] and 8.24% [67 mmol/mol], respectively); body weight (-1.50 kg; -2.17, -0.84; P < .001); and 2-hour postprandial glucose (-1.52 mmol/L [-27.5 mg/dL]; -2.15, -0.90 [-38.7, -16.2]; P < .001). Significantly more exenatide QW + IG-treated patients vs placebo + IG-treated patients reached HbA1c <7.0% (<53 mmol/mol) (32.5% vs 7.4%; P < .001); daily IG dose increased by 2 and 4 units, respectively. Gastrointestinal and injection-site adverse events were more frequent with exenatide QW + IG (15.1% and 7.8%, respectively) than with placebo + IG (10.8% and 3.0%, respectively); hypoglycaemia incidence was similar between the exenatide QW + IG (29.7%) and placebo + IG (29.0%) groups, with no major hypoglycaemic events.. Among patients with inadequate glycaemic control, exenatide QW significantly improved glucose control and decreased body weight, without increased hypoglycaemia or unexpected safety findings.

Topics: Aged; Body Mass Index; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Drug Monitoring; Drug Therapy, Combination; Exenatide; Female; Follow-Up Studies; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Incretins; Insulin Glargine; Male; Middle Aged; Obesity; Weight Loss

Rationale Post-stroke hyperglycemia occurs in up to 50% of patients presenting with acute ischemic stroke. It reduces the efficacy of thrombolysis, increases infarct size, and worsens clinical outcomes. Insulin-based therapies have generally not been beneficial in treating post-stroke hyperglycemia as they are difficult to implement, may cause hypoglycaemia, possibly increase mortality and worsen clinical outcomes. Exenatide may be a safer, simpler, and more effective alternative to insulin in acute ischemic stroke. Design TEXAIS is a three year, Phase 2, multi-center, prospective, randomized, open label, blinded end-point trial comparing exenatide to standard of care. It aims to recruit 528 patients with a primary end point of major neurological improvement at 7 days defined as a ≥8-point improvement in NIHSS score, or NIHSS 0-1. Secondary outcomes of hyper- and hypoglycaemia at 5 days and NIHSS and mRS at 90 days will be measured. The treatment arm will receive exenatide 5 µg subcutaneously twice daily. The control arm will receive standard stroke unit care. Continuous glucose monitors will track the dynamic variability of glucose. Conclusion TEXAIS aims to show that exenatide is safe and effective in the treatment of post-stroke hyperglycemia. It has been designed to be highly generalizable with an ability to enroll a large percentage of patients with acute ischemic stroke, regardless of admission blood glucose level, diabetes status, or stroke severity, with very low risk of hypoglycemia. Trial registration: ClinicalTrials.gov/ANZCTR NTA1127.

Topics: Adolescent; Adult; Aged; Brain Ischemia; Exenatide; Female; Humans; Hyperglycemia; Hypoglycemic Agents; Male; Middle Aged; Prospective Studies; Stroke; Treatment Outcome; Young Adult

We performed a randomized controlled trial with the glucagon-like peptide-1 (GLP-1) receptor agonist exenatide as add-on to standard peri-operative insulin therapy in patients undergoing elective cardiac surgery. The aims of the study were to intensify peri-operative glucose control while minimizing the risk of hypoglycaemia and to evaluate the suggested cardioprotective effects of GLP-1-based treatments. A total of 38 patients with decreased left ventricular systolic function (ejection fraction ≤50%) scheduled for elective coronary artery bypass grafting (CABG) were randomized to receive either exenatide or placebo in a continuous 72-hour intravenous (i.v.) infusion on top of standard peri-operative insulin therapy. While no significant difference in postoperative echocardiographic variables was found between the groups, participants receiving exenatide showed improved peri-operative glucose control as compared with the placebo group (average glycaemia 6.4 ± 0.5 vs 7.3 ± 0.8 mmol/L; P < .001; percentage of time in target range of 4.5-6.5 mmol/L 54.8% ± 14.5% vs 38.6% ± 14.4%; P = .001; percentage of time above target range 39.7% ± 13.9% vs 52.8% ± 15.2%; P = .009) without an increased risk of hypoglycaemia (glycaemia <3.3 mmol/L: 0.10 ± 0.32 vs 0.21 ± 0.42 episodes per participant; P = .586). Continuous administration of i.v. exenatide in patients undergoing elective CABG could provide a safe option for intensifying the peri-operative glucose management of such patients.

Topics: Aged; Cardiotonic Agents; Coronary Artery Bypass; Czech Republic; Drug Therapy, Combination; Exenatide; Female; Glucagon-Like Peptide-1 Receptor; Heart; Hospitals, University; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Incidence; Incretins; Infusions, Intravenous; Insulin; Intraoperative Complications; Male; Peptides; Perioperative Care; Postoperative Complications; Proof of Concept Study; Risk; Single-Blind Method; Venoms; Ventricular Dysfunction, Left

To characterize gastrointestinal adverse events (AEs) with different glucagon-like peptide-1 receptor agonists (GLP-1RAs).. Two retrospective intention-to-treat analyses of 6-month patient-level data were conducted. Data from three studies comparing exenatide once weekly (n = 617) with exenatide twice daily (n = 606) were pooled, and one (DURATION-6) comparing exenatide once weekly (n = 461) with liraglutide (n = 450) was analysed separately. Patient-reported gastrointestinal AEs were classified as upper or lower, AE incidences and timing were determined, subgroups were analysed, and associations of gastrointestinal AEs with efficacy were examined.. Nausea was the most common gastrointestinal AE for all treatments. Fewer exenatide once-weekly-treated vs exenatide twice-daily- or liraglutide-treated patients reported gastrointestinal AEs (34% vs 45% and 25% vs 41%, respectively; both P  < .0001). Fewer exenatide once-weekly-treated patients reported upper plus lower events than liraglutide-treated patients ( P  < .001); the difference between exenatide once weekly and twice daily was not significant. Within each group, more women than men reported gastrointestinal AEs. Events occurrred early and were predominantly mild. Glycated haemoglobin reductions were similar for patients with or without gastrointestinal AEs. Weight loss was greater for patients with gastrointestinal AEs with exenatide once weekly and exenatide twice daily ( P  < .05); no difference was observed in DURATION-6.. Gastrointestinal AEs were less frequent with exenatide once weekly vs exenatide twice daily or liraglutide, and combined upper and lower events occurred less often. Gastrointestinal AEs were typically mild and occurred early. Gastrointestinal AEs did not affect glycaemic control but may be associated with greater weight loss.

Topics: Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Female; Gastrointestinal Diseases; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Incidence; Incretins; Intention to Treat Analysis; Liraglutide; Male; Nausea; Patient Dropouts; Peptides; Retrospective Studies; Self Report; Severity of Illness Index; Sex Factors; Venoms; Weight Loss

Glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors treat type 2 diabetes through incretin-signaling pathways. This study compared the efficacy and safety of the glucagon-like peptide-1 receptor agonist exenatide once-weekly (Miglyol) suspension for autoinjection (QWS-AI) with the dipeptidyl peptidase-4 inhibitor sitagliptin or placebo.. In this open-label, multicentre study of patients with type 2 diabetes who had suboptimal glycaemic control on metformin monotherapy, 365 patients were randomized to receive exenatide 2.0 mg QWS-AI, sitagliptin 100 mg once daily or oral placebo (3:2:1 ratio). The primary endpoint was change in glycated hemoglobin (HbA1c) from baseline to 28 weeks.. At 28 weeks, exenatide QWS-AI significantly reduced HbA1c from baseline compared to sitagliptin (-1.13% vs -0.75% [baseline values, 8.42% and 8.50%, respectively]; P  = .02) and placebo (-0.40% [baseline value, 8.50%]; P = .001). More exenatide QWS-AI-treated patients achieved HbA1c <7.0% than did sitagliptin- or placebo-treated patients (43.1% vs 32.0% and 24.6%; both P  < .05). Exenatide QWS-AI and sitagliptin reduced fasting plasma glucose from baseline to 28 weeks (-21.3 and -11.3 mg/dL) vs placebo (+9.6 mg/dL), with no significant difference between the 2 active treatments. Body weight decreased with both active treatments (-1.12 and -1.19 kg), but not with placebo (+0.15 kg). No improvement in blood pressure was observed in any group. The most common adverse events with exenatide QWS-AI were gastrointestinal events and injection-site reactions.. This study demonstrated that exenatide QWS-AI reduced HbA1c more than sitagliptin or placebo and was well tolerated.

Topics: Cardiovascular Diseases; Cohort Studies; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Cardiomyopathies; Drug Therapy, Combination; Excipients; Exenatide; Female; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Incidence; Incretins; Injections, Jet; Male; Metformin; Middle Aged; Peptides; Sitagliptin Phosphate; Triglycerides; United States; Venoms

We evaluated the influence of short-term treatment with exenatide twice daily or liraglutide once daily on daily blood glucose fluctuations in 40 patients with type 2 diabetes inadequately controlled by sulfonylureas. The patients in a multicenter, open-label trial were randomly assigned to receive add-on exenatide (10 μg/day, n = 21) or add-on liraglutide (0.3-0.9 mg/day, n = 19), and underwent 24-hour continuous subcutaneous glucose monitoring. There was no significant between-group difference in glucose fluctuations during the day, as assessed by calculating mean amplitude of glycemic excursion (MAGE) and standard deviation (SD). However, the mean blood glucose levels at 3 hours after breakfast and dinner were significantly lower in the exenatide group than the liraglutide group (breakfast: 127.3 ± 24.1 vs. 153.4 ± 28.7 mg/dL; p = 0.006, dinner: 108.7 ± 17.3 vs. 141.9 ± 24.2 mg/dL; p < 0.001). In contrast, mean blood glucose levels and their SD were significantly lower between 0000 h and 0600 h in the liraglutide group than the exenatide group (average glucose: 126.9 ± 27.1 vs. 107.1 ± 24.0 mg/dL; p = 0.029, SD: 15.2 ± 10.5 vs. 8.7 ± 3.8; p = 0.020). Both groups had similar glucose fluctuations despite differences in 24-hour blood glucose profiles. Therefore, each of these agents may have advantages or disadvantages and should be selected according to the blood glucose profile of the patient.

Topics: Aged; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Resistance; Drug Therapy, Combination; Exenatide; Female; Glucose; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Injections, Subcutaneous; Japan; Liraglutide; Male; Middle Aged; Monitoring, Ambulatory; Peptides; Subcutaneous Tissue; Sulfonylurea Compounds; Venoms

Both hyperglycaemia and hypoglycaemia in acute ischaemic stroke (AIS) are associated with increased infarct size and worse functional outcomes. Thus, therapies that can maintain normoglycaemia during stroke are clinically important. Glucagon-like peptide 1 (GLP-1) analogues, including exenatide, are routinely used in the treatment of hyperglycaemia in type 2 diabetes, but data on the usefulness of this class of agents in the management of elevated glucose levels in AIS are limited. Owing to their glucose-dependent mechanism of action, GLP-1 analogues are associated with a low risk of hypoglycaemia, which may give them an advantage over intensive insulin therapy in the acute management of hyperglycaemia in this setting.. The Short-Term EXenatide therapy in Acute ischaemic Stroke study is a randomised, open-label, parallel-group pilot study designed to investigate the efficacy of exenatide at lowering blood glucose levels in patients with hyperglycaemia with AIS. A total of 30 patients presenting with AIS and blood glucose levels >10 mmol/L will be randomised to receive the standard therapy (intravenous insulin) or intravenous exenatide for up to 72 h. Outcomes including blood glucose levels within the target range (5-10 mmol/L), the incidence of hypoglycaemia and the feasibility of administering intravenous exenatide in this patient population will be assessed. A follow-up visit at 3 months will facilitate evaluation of neurological outcomes post-stroke.. This study has been approved by the local Institutional Review Board (Northern Sydney Local Health District Human Research Ethics Committee). The study results will be communicated via presentations at scientific conferences and through publication in peer-reviewed journals.. As GLP-1 analogues require elevated glucose levels to exert their insulin potentiating activity, the use of exenatide in the management of hyperglycaemia in AIS may reduce the incidence of hypoglycaemia, thereby conferring a benefit in morbidity and mortality for patients in the long term.. ACTRN12614001189617.

Topics: Blood Glucose; Exenatide; Female; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Male; Peptides; Pilot Projects; Research Design; Stroke; Treatment Outcome; Venoms

Allogeneic human islet transplantation is an effective therapy for the treatment of patients with Type 1 Diabetes (T1D). The low number of islet transplants performed worldwide and the different transplantation protocols used limit the identification of the most effective therapeutic options to improve the efficacy of this approach.. We present a retrospective analysis on the data collected from 44 patients with T1D who underwent islet transplantation at our institute between 2000 and 2007. Several variables were included: recipient demographics and immunological characteristics, donor and transplant characteristics, induction protocols, and additional medical treatment received. Immunosuppression was induced with anti-CD25 (Daclizumab), alone or in association with anti-tumor necrosis factor alpha (TNF-α) treatments (Etanercept or Infliximab), or with anti-CD52 (Alemtuzumab) in association with anti-TNF-α treatments (Etanercept or Infliximab). Subsets of patients were treated with Filgrastim for moderate/severe neutropenia and/or Exenatide for post prandial hyperglycemia.. The analysis performed indicates a negative association between graft survival (c-peptide level ≥ 0.3 ng/ml) and islet infusion volume, with the caveat that, the progressive reduction of infusion volumes over the years has been paralleled by improved immunosuppressive protocols. A positive association is instead suggested between graft survival and administration of Exenatide and Filgrastim, alone or in combination.. This retrospective analysis may be of assistance to further improve long-term outcomes of protocols for transplant of islets and other organs.

Topics: Adult; Aged; Antibodies, Monoclonal, Humanized; Daclizumab; Exenatide; Filgrastim; Graft Survival; Hematologic Agents; Humans; Hyperglycemia; Hypoglycemic Agents; Immunoglobulin G; Immunosuppressive Agents; Islets of Langerhans; Islets of Langerhans Transplantation; Middle Aged; Neutropenia; Peptides; Retrospective Studies; Transplantation, Homologous; Venoms

To compare treatment satisfaction among people with type 2 diabetes receiving dulaglutide 1.5 mg and dulaglutide 0.75 mg (a once-weekly, long-acting, glucagon-like peptide-1 receptor agonist) with those receiving either exenatide or placebo (AWARD-1 study) or metformin (AWARD-3 study) over 52 weeks.. The Diabetes Treatment Satisfaction Questionnaire status version (DTSQs) and change version (DTSQc) were used to evaluate total treatment satisfaction and perceived frequency of hyperglycaemia and hypoglycaemia.. In the AWARD-1 study, significant improvements from baseline were observed in total DTSQs score for both dulaglutide doses (26 and 52 weeks) and exenatide (26 weeks). The improvement was significantly greater with both dulaglutide doses compared with placebo (26 weeks) and exenatide (26 and 52 weeks). The perceived frequency of hyperglycaemia was lower for all groups at 26 and 52 weeks compared with baseline. The improvement was greater with both dulaglutide doses and exenatide compared with placebo at 26 weeks, and was also greater with both dulaglutide doses compared with exenatide at 26 and 52 weeks. The exenatide group had an increase in perceived frequency of hypoglycaemia at 26 and 52 weeks. In the AWARD-3 study, significant improvements from baseline were observed for total DTSQs scores in all groups at 26 and 52 weeks. Perceived frequency of hyperglycaemia was lower for all groups at 26 and 52 weeks compared with baseline, and this improvement was greater with both dulaglutide doses compared with metformin at 52 weeks.. Dulaglutide was associated with improvements in treatment satisfaction and a decrease in perceived frequency of hyperglycaemia.

Topics: Adult; Diabetes Mellitus; Double-Blind Method; Drug Administration Schedule; Exenatide; Female; Glucagon-Like Peptides; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Male; Metformin; Middle Aged; Patient Satisfaction; Peptides; Recombinant Fusion Proteins; Surveys and Questionnaires; Time Factors; Venoms

To determine the effect of chronic daily exenatide treatment on β-cell function in type 2 diabetes (T2DM).. Glucagon-like peptide receptor agonists, such as exenatide, are commonly used to treat patients with T2DM. Drugs in this class are insulinotropic but lower blood glucose by multiple mechanisms such that effects on β-cell function can be difficult to discern by conventional measures.. Seventy-nine subjects with previously untreated T2DM were studied before and after 24 weeks of treatment with one of the two doses of exenatide, 5- or 10-μg twice daily, or placebo. All subjects had oral glucose tolerance tests (OGTT) before and after randomization with measurement of plasma glucose, insulin and C-peptide concentrations. Insulin secretion rates (ISR), peripheral insulin sensitivity (OGIS) and hepatic insulin resistance index (Hep-IR) were calculated.. During the trial, all three groups lost similar, small but significant, amounts of weight. Compared to placebo, 24 weeks of daily high- or low-dose exenatide treatment reduced HbA1c and improved fasting and postprandial hyperglycaemia. Exenatide was associated with improved OGIS and Hep-IR independent of changes in weight. Plasma insulin levels and ISR during the OGTT did not differ before or after treatment with exenatide or placebo. However, when considered as a function of plasma glucose and insulin sensitivity, both doses of exenatide improved ISR proportionately to the improvement in plasma glucose. The higher dose of exenatide was associated with a significant improvement in β-cell sensitivity to glucose.. These findings demonstrate that in persons with early T2DM, chronic treatment with exenatide enhanced ISR and increased β-cell sensitivity to glucose. These improvements in β-cell function were not clearly reflected in plasma insulin and C-peptide levels, but became apparent when glycemia and insulin sensitivity were accounted for.

Topics: Diabetes Mellitus, Type 2; Exenatide; Female; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Male; Middle Aged; Peptides; Venoms

Exenatide treatment improves glycemia in adults with type 2 diabetes and has been shown to reduce postprandial hyperglycemia in adolescents with type 1 diabetes. We studied the effects of exenatide on glucose homeostasis in adults with long-standing type 1 diabetes.. Fourteen patients with type 1 diabetes participated in a crossover study of 6 months' duration on exenatide (10 μg four times a day) and 6 months off exenatide. We assessed changes in fasting and postprandial blood glucose and changes in insulin sensitivity before and after each study period.. High-dose exenatide therapy reduced postprandial blood glucose but was associated with higher fasting glucose concentrations without net changes in hemoglobin A1c. Exenatide increased insulin sensitivity beyond the effects expected as a result of weight reduction.. Exenatide is a promising adjunctive agent to insulin therapy because of its beneficial effects on postprandial blood glucose and insulin sensitivity in patients with type 1 diabetes.

Topics: Adult; Blood Glucose; Body Weight; Cross-Over Studies; Diabetes Mellitus, Type 1; Drug Administration Schedule; Exenatide; Fasting; Female; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin Resistance; Male; Middle Aged; Peptides; Postprandial Period; Venoms

Hyperglycemia upon hospital admission in patients with ST-segment elevation myocardial infarction (STEMI) occurs frequently and is associated with adverse outcomes. It is, however, unsettled as to whether an elevated blood glucose level is the cause or consequence of increased myocardial damage. In addition, whether the cardioprotective effect of exenatide, a glucose-lowering drug, is dependent on hyperglycemia remains unknown. The objectives of this substudy were to evaluate the association between hyperglycemia and infarct size, myocardial salvage, and area at risk, and to assess the interaction between exenatide and hyperglycemia. A total of 210 STEMI patients were randomized to receive intravenous exenatide or placebo before percutaneous coronary intervention. Hyperglycemia was associated with larger area at risk and infarct size compared with patients with normoglycemia, but the salvage index and infarct size adjusting for area at risk did not differ between the groups. Treatment with exenatide resulted in increased salvage index both among patients with normoglycemia and hyperglycemia. Thus, we conclude that the association between hyperglycemia upon hospital admission and infarct size in STEMI patients is a consequence of a larger myocardial area at risk but not of a reduction in myocardial salvage. Also, cardioprotection by exenatide treatment is independent of glucose levels at hospital admission. Thus, hyperglycemia does not influence the effect of the reperfusion treatment but rather represents a surrogate marker for the severity of risk and injury to the myocardium.

Topics: Acute Disease; Aged; Cardiotonic Agents; Exenatide; Female; Heart; Humans; Hyperglycemia; Hypoglycemic Agents; Male; Middle Aged; Myocardial Infarction; Myocardium; Peptides; Risk; Severity of Illness Index; Venoms

The purpose of this study was to evaluate the advantages of exenatide treatment on obesity and non-alcoholic fatty liver disease (NAFLD) with elevated liver enzymes in patients with type 2 diabetes (T2D).. A total of 60 newly diagnosed patients with obesity, NAFLD with elevated liver enzymes and T2D were included in the study. The patients were randomly divided into two groups. The exenatide treatment group (n = 30) were treated with exenatide and insulin glargine, and the intensive insulin therapy group (n = 30) were treated with insulin aspart and insulin glargine for 12 weeks. Selected clinical characteristics were determined, and ultrasonography was performed at both baseline and 12 weeks following treatment.. At baseline, the clinical characteristics were matched between the two groups. After 12 weeks, fasting blood glucose (FBG), postprandial blood glucose (PBG), glycosylated haemoglobin (HbA1c), total cholesterol (TC), triglyceride (TG) and total bilirubin levels were significantly decreased in the two groups (p < 0.001). Body weight and waist circumference were significantly decreased in the exenatide group but increased in the intensive insulin group (p < 0.001). The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and γ-glutamyl transpeptidase (γGGT) in the exenatide group were significantly lower than in the intensive insulin group (p < 0.001). The mean body weight change correlated with the levels of ALT, AST and γGGT change (ALT, r = 0.761; AST, r = 0.733; γGGT, r = 0.752; p < 0.001). Moreover, the reversal rate of fatty liver was significantly higher in the exenatide group (93.3%) than the intensive insulin group (66.7%) (p < 0.01).. Exenatide has a better hepatic-protective effect than intensive insulin therapy and perhaps represents a unique option for adjunctive therapy for patients with obesity, non-alcoholic fatty liver disease with elevated liver enzymes and T2D.

Topics: Adult; Biomarkers; Body Mass Index; Combined Modality Therapy; Diabetes Mellitus, Type 2; Diet, Diabetic; Drug Therapy, Combination; Exenatide; Exercise; Female; Glycated Hemoglobin; Hepatic Insufficiency; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; Liver; Male; Middle Aged; Non-alcoholic Fatty Liver Disease; Obesity; Peptides; Ultrasonography; Venoms; Waist Circumference; Weight Loss

Mealtime insulin is commonly added to manage hyperglycemia in type 2 diabetes when basal insulin is insufficient. However, this complex regimen is associated with weight gain and hypoglycemia. This study compared the efficacy and safety of exenatide twice daily or mealtime insulin lispro in patients inadequately controlled by insulin glargine and metformin despite up-titration.. In this 30-week, open-label, multicenter, randomized, noninferiority trial with 12 weeks prior insulin optimization, 627 patients with insufficient postoptimization glycated hemoglobin A1c (HbA1c) were randomized to exenatide (10-20 µg/day) or thrice-daily mealtime lispro titrated to premeal glucose of 5.6-6.0 mmol/L, both added to insulin glargine (mean 61 units/day at randomization) and metformin (mean 2,000 mg/day).. Randomization HbA1c and fasting glucose (FG) were 8.3% (67 mmol/mol) and 7.1 mmol/L for exenatide and 8.2% (66 mmol/mol) and 7.1 mmol/L for lispro. At 30 weeks postrandomization, mean HbA1c changes were noninferior for exenatide compared with lispro (-1.13 and -1.10%, respectively); treatment differences were -0.04 (95% CI -0.18, 0.11) in per-protocol (n = 510) and -0.03 (95% CI -0.16, 0.11) in intent-to-treat (n = 627) populations. FG was lower with exenatide than lispro (6.5 vs. 7.2 mmol/L; P = 0.002). Weight decreased with exenatide and increased with lispro (-2.5 vs. +2.1 kg; P < 0.001). More patients reported treatment satisfaction and better quality of life with exenatide than lispro, although a larger proportion of patients with exenatide experienced treatment-emergent adverse events. Exenatide resulted in fewer nonnocturnal hypoglycemic episodes but more gastrointestinal adverse events than lispro.. Adding exenatide to titrated glargine with metformin resulted in similar glycemic control as adding lispro and was well tolerated. These findings support exenatide as a noninsulin addition for patients failing basal insulin.

Topics: Aged; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Female; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Insulin; Insulin Glargine; Insulin Lispro; Insulin, Long-Acting; Male; Meals; Metformin; Middle Aged; Peptides; Quality of Life; Receptors, Glucagon; Treatment Outcome; Venoms

Postprandial hyperglycemia due to paradoxical hyperglucagonemia is a major challenge of diabetes treatment despite the use of the artificial pancreas. We postulated that adjunctive therapy with pramlintide or exenatide would attenuate hyperglycemia in the postprandial phase through glucagon suppression, thereby optimizing the functioning of the closed-loop (CL) system. Subjects with type 1 diabetes (T1DM) on insulin pump therapy were recruited to participate in a 27-hour hospitalized admission on 3 occasions (2-4 weeks apart) and placed on the insulin delivery via CL system in random order to receive (1) insulin alone (control), (2) exenatide 2.5 µg + insulin, (3) pramlintide 30 µg + insulin. Medications were given prior to lunch and dinner, which was a standardized meal of 60 grams of carbohydrates. Insulin delivery was as per the ePID algorithm via the Medtronic CL system and continuous subcutaneous glucose monitoring via Medtronic Sof-sensors. Ten subjects age 23 ± 1 years with a HbA1c of 7.29 ± 0.3% (56 ± 1 mmol/mol) and duration of T1DM 10.6 ± 2.0 years participated in the 3-part study. Exenatide was found to be significantly better in attenuating postprandial hyperglycemia as compared to insulin monotherapy (P < .03) and pramlintide (P > .05). Glucagon suppression was statistically significant with exenatide (P < .03) as compared to pramlintide. Insulin requirements were lower with adjunctive therapy, but statistically insignificant. Insulin monotherapy results in postprandial hyperglycemia in T1DM in the CL setting and adjunctive therapy with exenatide reduces postprandial hyperglycemia effectively and should be considered as adjunctive therapy in T1DM.

Topics: Adolescent; Adult; Algorithms; Blood Glucose; Diabetes Mellitus, Type 1; Exenatide; Female; Glucagon; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Infusion Systems; Islet Amyloid Polypeptide; Male; Pancreas, Artificial; Peptides; Venoms; Young Adult

We report the discovery and translational therapeutic efficacy of a peptide with potent, balanced co-agonism at both of the receptors for the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). This unimolecular dual incretin is derived from an intermixed sequence of GLP-1 and GIP, and demonstrated enhanced antihyperglycemic and insulinotropic efficacy relative to selective GLP-1 agonists. Notably, this superior efficacy translated across rodent models of obesity and diabetes, including db/db mice and ZDF rats, to primates (cynomolgus monkeys and humans). Furthermore, this co-agonist exhibited synergism in reducing fat mass in obese rodents, whereas a selective GIP agonist demonstrated negligible weight-lowering efficacy. The unimolecular dual incretins corrected two causal mechanisms of diabesity, adiposity-induced insulin resistance and pancreatic insulin deficiency, more effectively than did selective mono-agonists. The duration of action of the unimolecular dual incretins was refined through site-specific lipidation or PEGylation to support less frequent administration. These peptides provide comparable pharmacology to the native peptides and enhanced efficacy relative to similarly modified selective GLP-1 agonists. The pharmacokinetic enhancement lessened peak drug exposure and, in combination with less dependence on GLP-1-mediated pharmacology, avoided the adverse gastrointestinal effects that typify selective GLP-1-based agonists. This discovery and validation of a balanced and high-potency dual incretin agonist enables a more physiological approach to management of diseases associated with impaired glucose tolerance.

Topics: Acylation; Adolescent; Adult; Aged; Animals; Diabetes Mellitus, Type 2; Exenatide; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Haplorhini; Humans; Hyperglycemia; Incretins; Insulin; Liraglutide; Male; Mice; Middle Aged; Peptides; Rats; Receptors, Gastrointestinal Hormone; Receptors, Glucagon; Rodentia; Treatment Outcome; Venoms; Weight Loss; Young Adult

To quantify how much exenatide added to metformin improves β-cell function, and to evaluate the impact on glycaemic control, insulin resistance and inflammation compared with metformin alone.. A total of 174 patients with Type 2 diabetes with poor glycaemic control were instructed to take metformin for 8 ± 2 months, then they were randomly assigned to exenatide (5 μg twice a day for the first 4 weeks and forced titration to 10 μg twice a day thereafter) or placebo for 12 months. At 12 months we evaluated anthropometric measurements, glycaemic control, insulin resistance and β-cell function variables, glucagon, adiponectin, high sensitivity-C reactive protein and tumour necrosis factor-α. Before and after 12 months, patients underwent a combined euglycaemic hyperinsulinaemic and hyperglycaemic clamp, with subsequent arginine stimulation.. Exenatide + metformin gave a greater decrease in body weight, glycaemic control, fasting plasma proinsulin and insulin and their ratio, homeostasis model assessment for insulin resistance (HOMA-IR), and glucagon values and a greater increase in C-peptide levels, homeostasis model assessment β-cell function index (HOMA-β) and adiponectin compared with placebo + metformin. Exenatide + metformin decreased waist and hip circumference, and reduced concentrations of high sensitivity-C reactive protein and tumour necrosis factor-α. Exenatide + metformin gave a greater increase in M value (+34%), and disposition index (+55%) compared with placebo + metformin; first (+21%) and second phase (+34%) C-peptide response to glucose and C-peptide response to arginine (+25%) were also improved by exenatide + metformin treatment, but not by placebo + metformin.. Exenatide is effective not only on glycaemic control, but also in protecting β-cells and in reducing inflammation.

Topics: Adiponectin; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Exenatide; Fasting; Female; Glucose Clamp Technique; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin-Secreting Cells; Italy; Male; Metformin; Middle Aged; Peptides; Treatment Outcome; Tumor Necrosis Factor-alpha; Venoms; Weight Loss

Glucocorticoids (GCs) are regarded as diabetogenic because they impair insulin sensitivity and islet-cell function. This study assessed whether treatment with the glucagon-like peptide receptor agonist (GLP-1 RA) exenatide (EXE) could prevent GC-induced glucose intolerance.. A randomized, placebo-controlled, double-blind, crossover study in eight healthy men (age: 23.5 [20.0-28.3] years; BMI: 26.4 [24.3-28.0] kg/m(2)) was conducted. Participants received three therapeutic regimens for 2 consecutive days: 1) 80 mg of oral prednisolone (PRED) every day (q.d.) and intravenous (IV) EXE infusion (PRED+EXE); 2) 80 mg of oral PRED q.d. and IV saline infusion (PRED+SAL); and 3) oral placebo-PRED q.d. and intravenous saline infusion (PLB+SAL). On day 1, glucose tolerance was assessed during a meal challenge test. On day 2, participants underwent a clamp procedure to measure insulin secretion and insulin sensitivity.. PRED+SAL treatment increased postprandial glucose levels (vs. PLB+SAL, P = 0.012), which was prevented by concomitant EXE (vs. PLB+SAL, P = NS). EXE reduced PRED-induced hyperglucagonemia during the meal challenge (P = 0.018) and decreased gastric emptying (vs. PRED+SAL, P = 0.028; vs. PLB+SAL, P = 0.046). PRED+SAL decreased first-phase glucose- and arginine-stimulated C-peptide secretion (vs. PLB+SAL, P = 0.017 and P = 0.05, respectively), whereas PRED+EXE improved first- and second-phase glucose- and arginine-stimulated C-peptide secretion (vs. PLB+SAL; P = 0.017, 0.012, and 0.093, respectively).. The GLP-1 RA EXE prevented PRED-induced glucose intolerance and islet-cell dysfunction in healthy humans. Incretin-based therapies should be explored as a potential strategy to prevent steroid diabetes.

Topics: Adolescent; Adult; Blood Glucose; C-Peptide; Cross-Over Studies; Exenatide; Glucagon-Like Peptide 1; Glucocorticoids; Glucose Clamp Technique; Glucose Intolerance; Humans; Hyperglycemia; Hyperinsulinism; Hypoglycemic Agents; Insulin Resistance; Islets of Langerhans; Male; Peptides; Prednisone; Venoms; Young Adult

Study the effects of exenatide (EXE) plus rosiglitazone (ROSI) on beta-cell function and insulin sensitivity using hyperglycemic and euglycemic insulin clamp techniques in participants with type 2 diabetes on metformin.. In this 20-week, randomized, open-label, multicenter study, participants (mean age, 56 +/- 10 years; weight, 93 +/- 16 kg; A1C, 7.8 +/- 0.7%) continued their metformin regimen and received either EXE 10 microg b.i.d. (n = 45), ROSI 4 mg b.i.d. (n = 45), or EXE 10 microg b.i.d. + ROSI 4 mg b.i.d. (n = 47). Seventy-three participants underwent clamp procedures to quantitate insulin secretion and insulin sensitivity. RESULTS A1C declined in all groups (P < 0.05), but decreased most with EXE+ROSI (EXE+ROSI, -1.3 +/- 0.1%; ROSI, -1.0 +/- 0.1%, EXE, -0.9 +/- 0.1%; EXE+ROSI vs. EXE or ROSI, P < 0.05). ROSI resulted in weight gain, while EXE and EXE+ROSI resulted in weight loss (EXE, -2.8 +/- 0.5 kg; EXE+ROSI, -1.2 +/- 0.5 kg; ROSI, + 1.5 +/- 0.5 kg; P < 0.05 between and within all groups). At week 20, 1st and 2nd phase insulin secretion was significantly higher in EXE and EXE+ROSI versus ROSI (both P < 0.05). Insulin sensitivity (M value) was significantly higher in EXE+ROSI versus EXE (P = 0.014).. Therapy with EXE+ROSI offset the weight gain observed with ROSI and elicited an additive effect on glycemic control with significant improvements in beta-cell function and insulin sensitivity.

Topics: Aged; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Female; Glucose Clamp Technique; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Male; Metformin; Middle Aged; Peptides; Rosiglitazone; Thiazolidinediones; Treatment Outcome; Venoms; Weight Gain

Incretin-based therapies have provided additional options for the treatment of type 2 diabetes mellitus. The aim of our study was to evaluate the effects of exenatide compared to glibenclamide on body weight, glycemic control, beta-cell function, insulin resistance, and inflammatory state in patients with diabetes.. One hundred twenty-eight patients with uncontrolled type 2 diabetes mellitus receiving therapy with metformin were randomized to take exenatide 5 microg twice a day or glibenclamide 2.5 mg three times a day and titrated to exenatide 10 microg twice a day or glibenclamide 5 mg three times a day. We evaluated body weight, body mass index (BMI), glycated hemoglobin (HbA(1c)), fasting plasma glucose (FPG), postprandial plasma glucose (PPG), fasting plasma insulin (FPI), homeostasis model assessment insulin resistance (HOMA-IR) index, homeostasis model assessment beta-cell function (HOMA-beta) index, plasma proinsulin (PPr), PPr/FPI ratio, resistin, retinol binding protein-4 (RBP-4), and high-sensitivity C-reactive protein (Hs-CRP) at baseline and after 3, 6, 9, and 12 months.. Body weight and BMI decreased with exenatide and increased with glibenclamide. A similar improvement of HbA(1c), FPG, and PPG was obtained in both groups, whereas FPI decreased with exenatide and increased with glibenclamide. The HOMA-IR index decreased and the HOMA-beta index increased with exenatide but not with glibenclamide. A decrease of PPr was reported in both groups, but only glibenclamide decreased the PPr/FPI ratio. Resistin and RBP-4 decreased with exenatide and increased with glibenclamide. A decrease of Hs-CRP was obtained with exenatide, whereas no variations were observed with glibenclamide.. Both exenatide and glibenclamide gave a similar improvement of glycemic control, but only exenatide gave improvements of insulin resistance and beta-cell function, giving also a decrease of body weight and of inflammatory state.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Blood Glucose; Body Mass Index; Body Weight; C-Reactive Protein; Diabetes Mellitus, Type 2; Exenatide; Female; Glyburide; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Insulin Resistance; Insulin-Secreting Cells; Male; Metformin; Middle Aged; Peptides; Proinsulin; Resistin; Retinol-Binding Proteins, Plasma; Venoms; Young Adult

Endothelial dysfunction is frequently present in individuals with insulin resistance or type 2 diabetes and can be induced by high-fat or high-carbohydrate meals. Because exenatide reduces postprandial glucose and lipid excursions, we hypothesized that it may also improve postprandial endothelial function.. In a double-blinded randomized crossover design, postprandial endothelial function was examined in 28 individuals with impaired glucose tolerance or recent-onset type 2 diabetes after a single injection of exenatide or placebo given just before a high-fat meal. Endothelial function was determined with peripheral arterial tonometry pre- and postprandially.. Postprandial endothelial function was higher after exenatide compared with placebo (P = 0.0002). In the placebo phase, postprandial change in endothelial function was inversely associated with mean postprandial concentrations of triglycerides (r = -0.62, P = 0.0004). Changes in postprandial triglyceride concentrations explained 64% of exenatide's effect on postprandial endothelial function.. Exenatide ameliorates postprandial endothelial dysfunction after a high-fat meal.

Topics: Adult; Age of Onset; Aged; Cohort Studies; Cross-Over Studies; Diabetes Mellitus, Type 2; Dietary Fats; Endothelium; Exenatide; Female; Glucose Intolerance; Humans; Hyperglycemia; Hypoglycemic Agents; Male; Middle Aged; Peptides; Triglycerides; Venoms

To assess the effect of a 4-week adjunctive therapy of exenatide (EXE) (5-10 microg b.i.d.) or sitagliptin (SITA) (100 mg once daily) in response to a standardized breakfast meal challenge in 48 men or women with type 2 diabetes receiving insulin glargine (GLAR) + metformin (MET).. This was a single-center, randomized, open-label, active comparator-controlled study with a three-arm parallel group design, consisting of: screening, 4- to 8-week run-in period, 4-week treatment period, and follow-up. In all three groups, the GLAR dose was titrated according to an algorithm (fasting blood glucose

Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Female; Follow-Up Studies; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Glargine; Insulin, Long-Acting; Male; Metformin; Middle Aged; Peptides; Treatment Outcome; Venoms

This study aimed to assess the relative contributions of postprandial and fasting glucose concentrations to overall hyperglycaemia.. Patients with type 2 diabetes (n=973) carried out self-monitored blood glucose (SMBG) profiles on entry into the European Exenatide (EUREXA) trial. Glucose area under the curve was calculated for postprandial excursions (AUC(ppg)) and total daytime concentrations >6.1 mmol/L (AUC(total)), as well as for the percentage of glycaemia due to postprandial excursions (%(ppg)). In addition, OGTT scores were assessed for each patient. Results were evaluated according to defined HbA(1c) categories.. There was a significant linear relationship between HbA(1c) and the derived variables of AUC(ppg), AUC(total) and %(ppg) (P<0.001 for each), with explained variance greatest for AUC(total) (r(2)=37.4%). AUC(ppg) increased only slightly up to an HbA(1c) of 7.0%, but showed a steeper increase in higher HbA(1c) categories. Also, the increase in AUC(total) with increasing HbA(1c) was much more pronounced. As a result, the postprandial glucose excursion as a proportion of total glucose (%(ppg)) decreased across HbA(1c) categories from 61.0% at HbA(1c)<6.5% to 22.0% at HbA(1c)≥9.0%. HOMA-IR remained virtually unchanged through all HbA(1c) categories, while HOMA-B showed no large changes up to HbA(1c) 7.0%, but then decreased at higher HbA(1c) values. The ΔI30/ΔG30 ratio decreased in the HbA(1c) 7.0-7.9% category, but did not change greatly at higher HbA(1c) categories.. With increasing HbA(1c), there was a decrease in the contribution of postprandial hyperglycaemia to total glycaemia, and fasting hyperglycaemia became more important. This is consistent with impaired insulin release, particularly first-phase release, at higher HbA(1c) levels.

Topics: Aged; Aged, 80 and over; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Exenatide; Fasting; Female; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin Resistance; Male; Middle Aged; Peptides; Venoms

The initial success of islet transplantation (ITx) is followed by graft dysfunction (GDF) and insulin reintroduction. Exenatide, a GLP-1 agonist, increases insulin and decreases glucagon secretion and has potential for beta-cell regeneration. To improve functional islet mass, exenatide treatment was given to ITx recipients with GDF. The objective of this study was to assess metabolic and hormonal effects of exenatide in GDF. In this prospective, single-arm, nonrandomized study, 11 type 1 diabetes recipients of ITx with GDF had HbA1c, weight, insulin requirements, and 5-h mixed meal tolerance test (MMTT; with/without exenatide given before test) at baseline, 3, 6, and 12 months after initiating exenatide treatment. Baseline MMTT showed postprandial hyperglycemia and hyperglucagonemia. Daily exenatide treatment resulted in improved glucose, increased amylin/insulin ratio, and decreased proinsulin/insulin ratio as assessed by MMTT. Glucagon responses remained unchanged. Exenatide administration 1 h before MMTT showed decreased glucagon and glucose at 0 min and attenuation in their postprandial rise. Time-to-peak glucose was delayed, followed by insulin, proinsulin, amylin, and C-peptide, indicating glucose-driven insulin secretion. Five subjects completed 12-month follow-up. Glucose and glucagon suppression responses after MMTT with exenatide were no longer observed. Retrospective 3-month analysis of these subjects revealed higher and sustained glucagon levels that did not suppress as profoundly with exenatide administration, associated with higher glucose levels and increased C-peptide responses. In conclusion, Exenatide suppresses the abnormal postprandial hyperglucagonemia and hyperglycemia observed in GDF. Changes in amylin and proinsulin secretion may reflect more efficient insulin processing. Different degrees of responsiveness to exenatide were identified. These may help guide the clinical management of ITx recipients.

Topics: Adult; Amyloid; Area Under Curve; C-Peptide; Demography; Diabetes Mellitus, Type 1; Exenatide; Female; Glucagon; Glucose; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Secretion; Islet Amyloid Polypeptide; Islets of Langerhans; Islets of Langerhans Transplantation; Male; Middle Aged; Peptides; Primary Graft Dysfunction; Prospective Studies; Transplantation, Homologous; Venoms

To evaluate the effect of exenatide on gastric emptying (GE) in type 2 diabetes using scintigraphy.. Seventeen subjects with type 2 diabetes participated in a randomized, single-blind, 3-period, crossover study. In each 5-day period, 5 or 10 microg exenatide or placebo was administered subcutaneously BID. Oral antidiabetic treatments were continued. The presence of cardiac autonomic neuropathy was assessed during screening. On day 5, after the morning dose, subjects consumed a 450-kcal breakfast containing (99m)Tc-labeled eggs and (111)In-labeled water, and GE was measured by scintigraphy. Plasma glucose and insulin, perceptions of appetite, and plasma exenatide were also quantified.. Exenatide slowed GE of both solid and liquid meal components [solid (T(50)(90% confidence interval [CI]); placebo, 60(50-70) min; 5 microg exenatide, 111(94-132) min; 10 microg exenatide, 169(143-201) min; both P<0.01); liquid (T(50)(90% CI), placebo, 34(25-46) min; 5 microg exenatide, 87(65-117) min; 10 microg exenatide, 114(85-154) min; both P<0.01)]. GE was not different between subjects with cardiac autonomic neuropathy (n=7), compared with those without (n=10) (P>/=0.68). Exenatide reduced postprandial glucose (area under the curve [AUC((0-6 h))]) by 69-76% and peak insulin (C(max)) by 84-86% compared with placebo. There was an inverse relationship between the postprandial rise in glucose (AUC((0-3 h))) and GE (solid T(50), r=-0.49, P<0.001).. Exenatide slows GE substantially in type 2 diabetes, which could be an important mechanism contributing to the beneficial effect of exenatide on postprandial glycemia.

Topics: Aged; Appetite; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Drug Tolerance; Exenatide; Female; Gastric Emptying; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Male; Middle Aged; Peptides; Postprandial Period; Safety; Single-Blind Method; Venoms

In this report, we quantify the effects of exenatide and glargine on the relative contributions of fasting and postprandial glucose (PPG) excursion to overall hyperglycemia based on self-monitored blood glucose. After 26 weeks of treatment, insulin glargine reduced fasting glucose to a greater extent than exenatide without significant effect on PPG excursion. The principal effect of exenatide on hyperglycemia was mitigating the rise in PPG with moderate improvement on fasting glucose. These findings may be limited by the fact that glucose measurements were collected through self-monitoring with six time points measured during the daytime, the meals were not standardized and the exact time for glucose measurements was unknown.

Topics: Aged; Area Under Curve; Blood Glucose; Blood Glucose Self-Monitoring; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Administration Schedule; Exenatide; Female; Humans; Hyperglycemia; Insulin; Insulin Glargine; Insulin, Long-Acting; Male; Middle Aged; Peptides; Postprandial Period; Risk Assessment; Single-Blind Method; Treatment Outcome; Venoms

This study evaluated the effects of exenatide, a novel incretin mimetic, in hyperglycemic patients with type 2 diabetes unable to achieve glycemic control with metformin-sulfonylurea combination therapy.. A 30-week, double-blind, placebo-controlled study was performed in 733 subjects (aged 55 +/- 10 years, BMI 33.6 +/- 5.7 kg/m(2), A1C 8.5 +/- 1.0%; means +/- SD) randomized to 5 microg subcutaneous exenatide b.i.d. (arms A and B) or placebo for 4 weeks. Thereafter, arm A remained at 5 microg b.i.d. and arm B escalated to 10 microg b.i.d. Subjects continued taking their dose of metformin and were randomized to either maximally effective (MAX) or minimum recommended (MIN) doses of sulfonylurea.. Week 30 A1C changes from baseline (+/-SE) were -0.8 +/- 0.1% (10 microg), -0.6 +/- 0.1% (5 microg), and +0.2 +/- 0.1% (placebo; adjusted P < 0.0001 vs. placebo), yielding placebo-adjusted reductions of -1.0% (10 microg) and -0.8% (5 microg). In the evaluable population, exenatide-treated subjects were more likely to achieve A1C < or =7% than placebo-treated subjects (34% [10 microg], 27% [5 microg], and 9% [placebo]; P < 0.0001). Both exenatide arms demonstrated significant weight loss (-1.6 +/- 0.2 kg from baseline each exenatide arm, -0.9 +/- 0.2 kg placebo; P < or = 0.01 vs. placebo). Mild or moderate nausea was the most frequent adverse event. The incidence of mild/moderate hypoglycemia was 28% (10 microg), 19% (5 microg), and 13% (placebo) and appeared lower with MIN than with MAX sulfonylurea treatment.. Exenatide significantly reduced A1C in patients with type 2 diabetes unable to achieve adequate glycemic control with maximally effective doses of combined metformin-sulfonylurea therapy. This improvement in glycemic control was associated with no weight gain and was generally well tolerated.

Topics: Adult; Aged; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Female; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Male; Metformin; Middle Aged; Peptides; Sulfonylurea Compounds; Venoms

This study evaluates the ability of the incretin mimetic exenatide (exendin-4) to improve glycemic control in patients with type 2 diabetes failing to achieve glycemic control with maximally effective metformin doses.. A triple-blind, placebo-controlled, 30-week study at 82 U.S. sites was performed with 336 randomized patients. In all, 272 patients completed the study. The intent-to-treat population baseline was 53 +/- 10 years with BMI of 34.2 +/- 5.9 kg/m(2) and HbA(1c) of 8.2 +/- 1.1%. After 4 weeks of placebo, subjects self-administered 5 microg exenatide or placebo subcutaneously twice daily for 4 weeks followed by 5 or 10 microg exenatide, or placebo subcutaneously twice daily for 26 weeks. All subjects continued metformin therapy.. At week 30, HbA(1c) changes from baseline +/- SE for each group were -0.78 +/- 0.10% (10 microg), -0.40 +/- 0.11% (5 microg), and +0.08 +/- 0.10% (placebo; intent to treat; adjusted P < 0.002). Of evaluable subjects, 46% (10 microg), 32% (5 microg), and 13% (placebo) achieved HbA(1c) < or =7% (P < 0.01 vs. placebo). Exenatide-treated subjects displayed progressive dose-dependent weight loss (-2.8 +/- 0.5 kg [10 microg], -1.6 +/- 0.4 kg [5 microg]; P < 0.001 vs. placebo). The most frequent adverse events were gastrointestinal in nature and generally mild to moderate. Incidence of mild to moderate hypoglycemia was low and similar across treatment arms, with no severe hypoglycemia.. Exenatide was generally well tolerated and reduced HbA(1c) with no weight gain and no increased incidence of hypoglycemia in patients with type 2 diabetes failing to achieve glycemic control with metformin.

Topics: Adult; Aged; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Female; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Male; Metformin; Middle Aged; Peptides; Proinsulin; Venoms

Current study was conducted to design and screen a long-lasting Exendin-4 analog for treating type 2 diabetes via the novel strategy of albumin binding combined with thrombin enzymolysis. First, a series of fusion peptides, containing different albumin-binding tags, a determinate thrombin-cleavable linker and a native Exendin-4, were prepared via chemosynthesis for in vitro and in vivo characterization. Surface plasmon resonance assay, thrombin cleavage assay and plasma stability test were performed for screening the optimal HEX peptide with enhanced albumin-binding affinity, controlled-release as well as plasma stability. The in vivo anti-diabetic efficacies of the selected candidate were further assessed via both acute and chronic pharmacodynamic evaluation in diabetic model animals. HEX15 exhibited either the highest affinity for human serum albumin or the superior in vitro stability and controlled release of Exendin-4 among 21 HEX peptides. Glucose tolerance test and hypoglycemic duration assay both revealed the notably improved the glucose tolerance and prolonged normoglycemic duration, respectively, of diabetic mice after single treatment of HEX15. Furthermore, chronic dosing of HEX15 significantly ameliorated the manifestations of diabetes in the db/db mice, including body weight, food intake, glycometabolism as well as hyperlipemia. Interestingly, combination therapy of HEX15 and long non-coding RNA-ENST00000411554 notably accelerated the wound healing and improved foot ulcer symptoms in model rats with diabetic foot ulcers. In summary, based on the strategy of linking the heptapeptide tag and thrombin-based sustained release, a long-acting Exendin-4 analog, HEX15, holds potential to be developed as a drug for ameliorating T2D as well as diabetic complications.

Topics: Albumins; Animals; Diabetes Complications; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Exenatide; Hyperglycemia; Hypoglycemic Agents; Mice; Peptides; Rats; Thrombin

To determine if Exendin-4 could be a therapeutic agent for burn-induced hyperglycemia.. Male Balb/c mice received a bolus of Exendin-4 intraperitoneally immediately after 15% total body surface area scald injury. Tail glucose levels were recorded and T-cell functions were analyzed at 4 h and 24 h postburn (pb). Pancreatic pathology was observed consecutively. The secretions of cytokines were detected in serum, spleen, and lung. Apoptosis of splenic CD3+ T-cells was examined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and flow cytometry.. Although Exendin-4 could attenuate burn-induced hyperglycemia in mice at 4 h pb, it accelerated their survival dose dependently with progressive depletion of splenocyte number. T-cell function underwent two-phasic changes following Exendin-4 treatment. Compared to placebo mice, T-cell from Exendin-4-treated mice was manifested with increased proliferation, while decreased IL-2 secretion and lower ratio of IL-4/IFN-γ at 4 h pb. However, at 24 h pb, it showed decreased proliferation, while increased IL-2 secretion and higher ratio of IL-4/IFN-γ. Exendin-4 could elicit higher circulating IL-6 and IL-10 levels at 4 h pb, which were pronounced in the lung at 24 h pb. In the meanwhile, severe inflammation could be found in the pancreas. At 24 h pb, the numbers of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling or caspase-3 positive cells and the apoptosis of CD3+ T-cells were significantly increased in the spleens of Exendin-4 mice relative to placebo mice.. These data support a pathogenic role of Exendin-4 signaling during thermal injury, warning against its clinical application in acute insults.

Topics: Animals; Burns; Caspase 3; Cytokines; DNA Nucleotidylexotransferase; Exenatide; Glucose; Hyperglycemia; Interleukin-10; Interleukin-2; Interleukin-4; Interleukin-6; Male; Mice; Mice, Inbred BALB C

Evidence that exendin-4, a glucagon-like peptide-1 analog, might be used to treat poorly healing wounds under diabetic and nondiabetic conditions has gained increasing interest. Little is known, however, about the effects of the drug on the production by dermal fibroblasts of key extracellular matrix and regulatory compounds. Therefore, we used human skin fibroblasts cultured in normo- (1 g/l = 5.6 mmol/l glucose) or hyperglycemic (4.5 g/l = 25 mmol/l glucose) culture medium to test the effects of exendin-4 (0 - 100 nmol/l) on fibroblast functions crucial for the wound healing process. Exendin-4 increased the proliferative and metabolic activities, as measured by the BrdU (bromodeoxyuridine) and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assays, respectively, of fibroblasts cultured in normoglycemic medium. Under hyperglycemic conditions, the drug had no effect on proliferation and reduced metabolic fibroblast activity. Exendin-4 decreased metalloproteinase-9 (MMP-9) secretion in the normoglycemic milieu only and increased tissue inhibitor of metalloproteinase-1 (TIMP-1) concentration in fibroblast colonies under both normo- and hyperglycemic experimental conditions. Exendin-4 increased the fibroblast growth factor-1 (FGF-1) concentration in cell colonies maintained in the normoglycemic milieu but decreased FGF-1 release when fibroblasts were grown in hyperglycemic medium. High glucose caused lactic dehydrogenase (LDH) leakage when compared with normoglycemic conditions, and exendin-4 was not able to prevent this effect, although it reduced LDH release from fibroblasts cultured in normoglycemic medium. Finally, exendin-4 increased glycosaminoglycan (GAG) content under both experimental conditions. Our results indicate that exendin-4 effects on the production of the extracellular matrix and regulatory proteins differ in human skin fibroblasts exposed to either normal or high glucose. In general, the beneficial effects of the drug, which may be important for the improvement of wound healing, are more pronounced under normoglycemic conditions, thus indicating that hyperglycemia attenuates the positive effects of exendin-4 on fibroblasts.

Topics: Cells, Cultured; Exenatide; Fibroblasts; Humans; Hyperglycemia; Skin; Tissue Inhibitor of Metalloproteinase-1

Exenatide is used to treat patients with type-2 diabetes and it also exerts cardioprotective effects. Here, we tested whether Exenatide attenuates hyperglycemia-related cardiomyocyte damage by inhibiting endoplasmic reticulum (ER) stress and the NF-κB signaling pathway. Our results demonstrated that hyperglycemia activates the NF-κB signaling pathway, eliciting ER stress. We also observed cardiomyocyte contractile dysfunction, inflammation, and cell apoptosis induced by hyperglycemia. Exenatide treatment inhibited inflammation, improved cardiomyocyte contractile function, and rescued cardiomyocyte viability. Notably, re-activation of the NF-κB signaling pathway abolished Exenatide's protective effects on hyperglycemic cardiomyocytes. Taken together, our results demonstrate that Exenatide directly reduces hyperglycemia-induced cardiomyocyte damage by inhibiting ER stress and inactivating the NF-κB signaling pathway.

Topics: Animals; Apoptosis; Cell Line; Diabetic Cardiomyopathies; Endoplasmic Reticulum Stress; Exenatide; Hyperglycemia; Hypoglycemic Agents; Inflammation; Myocytes, Cardiac; NF-kappa B; Rats; Signal Transduction

Olanzapine is a second-generation antipsychotic (SGA) used in the treatment of schizophrenia and a number of off-label conditions. Although effective in reducing psychoses, acute olanzapine treatment causes hyperglycemia. Pharmacological agonists of the glucagon-like peptide 1 (GLP1) receptor have been shown to offset weight gain associated with chronic SGA administration. It is not known whether GLP1 receptor agonism would mitigate the acute metabolic side effects of SGAs. Within this context, we sought to determine whether pharmacological targeting of the GLP1 receptor would be sufficient to protect against acute olanzapine-induced impairments in glucose and lipid homeostasis. Male C57BL/6J mice were treated with olanzapine and/or the GLP1 receptor agonists liraglutide and exendin 4, and the blood glucose response was measured. We found that liraglutide or exendin 4 completely protected male mice against olanzapine-induced hyperglycemia in parallel with increases in circulating insulin (liraglutide, exendin 4) and reductions in glucagon (liraglutide only). In additional experiments, female mice, which are protected from acute olanzapine-induced hyperglycemia, displayed hyperglycemia, increases in glucagon, and reductions in insulin when treated with olanzapine and the GLP1 receptor antagonist exendin 9-39 compared with olanzapine treatment alone. Although in some instances the pharmacological targeting of the GLP1 receptor attenuated indexes of olanzapine-induced lipolysis, increases in liver triglyceride accumulation were not impacted. Our findings provide evidence that signaling through the GLP1 receptor can remarkably influence acute olanzapine-induced hyperglycemia, and from the standpoint of protecting against acute excursions in blood glucose, GLP1 receptor agonists should be considered as an adjunct treatment approach.

Topics: Animals; Exenatide; Female; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Hyperglycemia; Hypoglycemic Agents; Lipolysis; Liraglutide; Liver; Male; Mice; Mice, Inbred C57BL; Olanzapine; Selective Serotonin Reuptake Inhibitors; Triglycerides

Glucagon-like peptide-1 receptor (GLP-1R) agonists have emerged as treatment options for type 2 diabetes mellitus (T2DM). Here, we designed a high-throughput GLP-1R extracellular domain (ECD)-based system that enabled the screening of high-potency receptor-biased GLP-1R agonists demonstrating new pharmacological virtues. Firstly, six 12-mer peptides (termed PEP01⁻06), screened from a large phage displayed peptide library were fused to the N-terminus of Exendin-4 (29⁻39) to generate PEP07⁻12. By the use of four lysine-altered PEP07 (PEP13⁻16) as the starting point, a series of fatty chain conjugates (PEP17⁻20) were synthesized and evaluated by in vitro GLP-1R-based cell assays. In addition, the acute and long-term in vivo effects on diet-induced obesity (DIO) mice were further evaluated. All four conjugates showed good receptor activation efficacy, and PEP20 was selected to undergo further assessment. Preclinical experiments in DIO mice demonstrated that PEP20 had significant insulinotropic activities and glucose-lowering abilities. Moreover, a prolonged antidiabetic effect of PEP20 was also observed by the hypoglycemic test in DIO mice. Furthermore, long-term treatment with PEP20 achieved beneficial effects on the food intake, weight gain, hemoglobin A1C (HbA1C) lowering activity, and glucose tolerance compared with the control and was similar to the Liraglutide. In conclusion, PEP20, a GLP-1R ECD-biased agonist, may provide a novel therapeutic approach to T2DM.

Topics: Amino Acid Sequence; Animals; Binding Sites; Cell Line; Diet, High-Fat; Exenatide; Fatty Acids; Gene Expression Regulation; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Glycoconjugates; Hyperglycemia; Hypoglycemic Agents; Insulin-Secreting Cells; Male; Mice; Obesity; Peptide Library; Peptides; Protein Binding; Rats; Structure-Activity Relationship

Hyperglycemia impairs glucagon-like peptide-1 receptor (GLP-1R) signaling in multiple cell types and thereby potentially attenuates the therapeutic effects of GLP-1R agonists. We hypothesized that the downregulation of GLP-1R by hyperglycemia might reduce the renal-protective effects of GLP-1R agonists in diabetic nephropathy (DN). In this study, we examined the effects of high glucose on the expression of GLP-1R and its signaling pathways in the HBZY-1 rat mesangial cell line. We found that high glucose reduced GLP-1R messenger RNA (mRNA) levels in HBZY-1 cells and in the renal cortex in db/db mice comparing with control groups. In consistence, GLP-1R agonist exendin-4 induced CREB phosphorylation was attenuated by high glucose but not low glucose treatment, which is paralleled with abrogated anti-inflammatory functions in HBZY-1 cells linked with nuclear factor-κB (NF-κB) activation. In consistence, GLP-1R inhibition aggravated the high glucose-induced activation of NF-κB and MCP-1 protein levels in cultured HBZY-1 cells while overexpression of GLP-1R opposite effects. We further proved that metformin restored high glucose-inhibited GLP-1R mRNA expression and decreased high glucose evoked inflammation in HBZY-1 cells. On the basis of these findings, we conclude that high glucose lowers GLP-1R expression and leads to inflammatory responses in mesangial cells, which can be reversed by metformin. These data support the rationale of combinative therapy of metformin with GLP-1R agonists in DN.

Topics: Animals; Cell Line; Chemokine CCL2; Diabetic Nephropathies; Exenatide; Glucagon-Like Peptide-1 Receptor; Glucose; Hyperglycemia; Mesangial Cells; Metformin; Mice; NF-kappa B

To investigate the chronic effects of twice-daily administration of stable apelin analogues, apelin-13 amide and pyroglutamyl (pGlu) apelin-13 amide, on metabolic variables in glucose-intolerant and insulin-resistant diet-induced obese mice fed a high-fat diet for 150 days.. Groups of mice received twice-daily (9 am and 5 pm) injections of saline vehicle, apelin-13 amide, (pGlu)apelin-13 amide or exendin-4(1-39) for 28 days (all at 25 nmol/kg). Energy intake, body weight, non-fasting blood glucose, plasma insulin, glucose tolerance, metabolic response to feeding and insulin sensitivity, together with pancreatic hormone content and biochemical variables such as lipids and total GLP-1 were monitored. Dual-energy X-ray absorptiometry analysis and indirect calorimetry were also performed.. Administration of apelin-13 amide, (pGlu)apelin-13 amide or exendin-4 significantly decreased body weight, food intake and blood glucose and increased plasma insulin compared with high-fat-fed saline-treated controls (P < .05 and P < .001), Additionally, all peptide-treated groups exhibited improved glucose tolerance (oral and intraperitoneal), metabolic responses to feeding and associated insulin secretion. (pGlu)apelin-13 amide also significantly improved glycated haemoglobin and insulin sensitivity after 28 days. Both (pGlu)apelin-13 amide and exendin-4 increased bone mineral content and decreased respiratory exchange ratio, whereas only (pGlu)apelin-13 amide increased energy expenditure. All treatment groups displayed reduced circulating triglycerides and increased glucagon-like peptide-1 concentrations, although only (pGlu)apelin-13 amide significantly reduced LDL cholesterol and total body fat, and increased pancreatic insulin content.. These data indicate the therapeutic potential of stable apelin-13 analogues, with effects equivalent to or better than those of exendin-4.

Topics: Adiposity; Amides; Animals; Anti-Obesity Agents; Diabetes Mellitus, Type 2; Diet, High-Fat; Drug Stability; Energy Intake; Energy Metabolism; Exenatide; Glucagon-Like Peptide-1 Receptor; Hyperglycemia; Hypoglycemic Agents; Insulin Resistance; Intercellular Signaling Peptides and Proteins; Male; Mice; Obesity; Weight Loss

A retrospective cohort study was conducted in patients with type 2 diabetes in an electronic medical record database to compare real-world, 6-month glycated haemoglobin (HbA1c) and weight outcomes for exenatide once weekly with those for dulaglutide and albiglutide. The study included 2465 patients: exenatide once weekly, n = 2133; dulaglutide, n = 201; and albiglutide, n = 131. The overall mean (standard deviation [s.d.]) age was 60 (11) years and 54% were men; neither differed among the comparison groups. The mean (s.d.) baseline HbA1c was similar in the exenatide once-weekly (8.3 [1.7]%) and dulaglutide groups (8.5 [1.5]%; P = .165), but higher in the albiglutide group (8.7 [1.7]%; P < .001). The overall mean (s.d.) HbA1c change was -0.5 (1.5)% (P < .001) and this did not differ among the comparison groups in either adjusted or unadjusted analyses. The mean (s.d.) weight change was -1.4 (4.7) kg for exenatide once weekly and -1.6 (3.7) kg for albiglutide (P = .579), but was greater for dulaglutide, at -2.7 (5.7) kg (P = .001). Outcomes were similar in subsets of insulin-naive patients with baseline HbA1c ≥7.0% or ≥9.0%. All agents significantly reduced HbA1c at 6 months, with no significant differences among agents or according to baseline HbA1c in insulin-naive subgroups.

Topics: Adult; Aged; Body Mass Index; Cohort Studies; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Male; Middle Aged; Obesity; Recombinant Fusion Proteins; Retrospective Studies; Weight Loss

Glucagon-like peptide-1 (GLP-1) stimulates insulin secretion, - plays anti-inflammatory role in atherosclerosis, and has surfactant-releasing effects in lungs. GLP-1 analogues are used in diabetes therapy. This is the first study to investigate the effects of exendin-4, a GLP-1 receptor agonist, on lung injury in diabetic mice. BALB/c male mice were divided into four groups. The first group was given only citrate buffer, the second group was given only exendin-4, the third group was given only streptozotocin (STZ), and the fourth group was given both exendin-4 and STZ. Exendin-4 (3μg/kg) was administered daily by subcutaneous injection for 30days after mice were rendered diabetic with a single dose of STZ (200mg/kg). Structural alterations, oxidative stress, apoptosis, insulin signaling and expressions of prosurfactant-C, alpha-smooth muscle actin, collagen-I and fibronectin were evaluated in lung tissue. Diabetic mice lungs were characterized by induced oxidative stress, apoptosis, edema, and cell proliferation. They had honeycomb-like alveoli, thicker alveolar walls, and hypertrophic pneumocytes. Although exendin-4 treatment improved pulmonary edema, apoptosis, oxidative stress, and lung injury, it led to the disrupted insulin signaling and interstitial collagen accumulation in the lungs of diabetic mice. Exendin-4 ameliorates hyperglycemia-mediated lung damage by reducing glucose, -oxidative stress and stimulating cell proliferation. However, exendin-4 led to increased lung injury partly by reducing insulin signaling - and collagen accumulation around pulmonary vasculature in diabetic mice.

Topics: Animals; Diabetes Complications; Diabetes Mellitus, Experimental; Exenatide; Hyperglycemia; Lung; Lung Injury; Male; Mice; Mice, Inbred BALB C; Oxidative Stress; Peptides; Respiratory Mucosa; Venoms

Glucagon-like peptide-1 (GLP-1) receptor agonists (liraglutide, exenatide, lixisenatide) have recently been used as anti-diabetes drugs. We examined relationships of the binding occupancy of GLP-1 receptors (Φ) and their clinical efficacy after administration of GLP-1 receptor agonists. Next, by focusing on changes of GLP-1 concentration after administration of dipeptidyl peptidase-4 (DPP-4) inhibitors (vildagliptin, alogliptin, sitagliptin, linagliptin), we analyzed the relationship between Φ and clinical efficacy. Furthermore, using Φ as a common parameter, we compared the clinical efficacy elicited by GLP-1 receptor agonists and DPP-4 inhibitors using a theoretical analysis method. The present results showed that GLP-1 receptor agonists produced their clinical effect at a relatively low level of Φ (1.1-10.7%) at a usual dose. Furthermore, it was suggested that the drugs might achieve their full effect at an extraordinarily low level of Φ. It was also revealed that the Φ value of DPP-4 inhibitors (0.83-1.3%) was at the lower end or lower than that of GLP-1 receptor agonists at a usual dose. Accordingly, the predicted value for hemoglobin A

Topics: Adamantane; Algorithms; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Drug Monitoring; Exenatide; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Ligands; Liraglutide; Models, Molecular; Molecular Targeted Therapy; Nitriles; Peptides; Piperidines; Pyrrolidines; Reproducibility of Results; Sitagliptin Phosphate; Uracil; Venoms; Vildagliptin

This study aimed to quantify the effect of the immediate release (IR) of exenatide, a short-acting glucagon-like peptide-1 (GLP-1) receptor agonist (GLP-1RA), on gastric emptying rate (GER) and the glucose rate of appearance (GluRA), and evaluate the influence of drug characteristics and food-related factors on postprandial plasma glucose (PPG) stabilization under GLP-1RA treatment. A quantitative systems pharmacology (QSP) approach was used, and the proposed model was based on data from published sources including: (1) GLP-1 and exenatide plasma concentration-time profiles; (2) GER estimates under placebo, GLP-1 or exenatide IR dosing; and (3) GluRA measurements upon food intake. According to the model's predictions, the recommended twice-daily 5- and 10-μg exenatide IR treatment is associated with GluRA flattening after morning and evening meals (48%-49%), whereas the midday GluRA peak is affected to a lesser degree (5%-30%) due to lower plasma drug concentrations. This effect was dose-dependent and influenced by food carbohydrate content, but not by the lag time between exenatide injection and meal ingestion. Hence, GER inhibition by exenatide IR represents an important additional mechanism of its effect on PPG.

Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Digestion; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Liberation; Exenatide; Gastric Emptying; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Incretins; Intestinal Absorption; Models, Biological; Postprandial Period; Systems Biology

It has been established that glucagon-like peptide 1 (GLP 1) inhibits pancreatic β-cell apoptosis, increases insulin secretion, and improves glucose tolerance in scald injury. However, the effects of Exendin-4, a long-acting incretin similar to GLP 1, remained unclear in severe scald injury. Hence, this study attempted to investigate whether Exendin-4 had similar effects by protecting the histology of pancreas in severely scalded rats.. One hundred sixty-two adult Wistar rats were equally randomized to sham burn group, burn group and burn with Exendin-4 treatment group. Rats were subjected to full skin thickness scald injuries (total body surface area: 50%) and were injected subcutaneously with Exendin-4 (4 μg/kg) twice daily. The histological changes of islets, the apoptosis of β cells, the amount of glucagon and insulin, and the concentration of plasma glucagon and insulin were observed; and the intraperitoneal glucose tolerance test was performed as well.. The islets and β cells were injured and the number of secretory granules decreased in the scalded rats, but less histopathological changes were seen in the rats treated with Exendin-4. The apoptosis index of treated rats was significantly lower than that of the scalded rats (p < 0.05). There was significant difference in β-cell density postinjury between the two groups (p < 0.05). More insulin and less glucagon in islets and plasma were found in the treated rats (p < 0.05), suggesting improved intraperitoneal glucose tolerance (p < 0.05) and fasting blood glucose (p < 0.05) in this group.. Based on our previous finding that GLP-1 could control hyperglycemia by increasing insulin secretion and inhibiting β-cell apoptosis in severe scald injuries, this study further confirmed that Exendin-4 could increase glycemic control following severe scald by preserving the histology of β cells in pancreatic islets and inhibiting their apoptosis.

Topics: Animals; Burns; Exenatide; Glucagon; Glucose Tolerance Test; Hyperglycemia; Insulin; Islets of Langerhans; Rats; Rats, Wistar

Epidemiological studies have demonstrated a close association of type 2 diabetes and hepatocellular carcinoma (HCC). Exenatide (Ex-4), a potent diabetes drug targeting glucagon-like peptide-1 receptor (GLP-1R), is protective against non-alcoholic fatty liver disease (NAFLD). However, the Ex-4 function and GLP-1R status have yet been explored in HCC. Herein we investigated the effect of Ex-4 in diethylnitrosamine (DEN)-treated mice consuming control or high-fat high-carbohydrate diet. Administration of Ex-4 significantly improved obesity-induced hyperglycemia and hyperlipidemia and reduced HCC multiplicity in obese DEN-treated mice, in which suppressed proliferation and induced apoptosis were confined to tumor cells. The tumor suppression effects of Ex-4 were associated with high expression of GLP-1R and activation of cyclic AMP (cAMP) and protein kinase A (PKA). Importantly, Ex-4 also downregulated epidermal growth factor receptor (EGFR) and signal transducer and activator of transcription 3 (STAT3), which lie downstream of cAMP-PKA signaling, resulting in suppression of multiple STAT3-targeted genes including c-Myc, cyclin D1, survivin, Bcl-2 and Bcl-xl. The growth inhibitory effects of Ex-4 were consistent in GLP-1R-abundant hepatoma cell lines and xenograft mouse model, wherein both PKA and EGFR had obligatory roles in mediating Ex-4 functions. In addition, Ex-4 also effectively suppressed inflammatory and fibrotic phenotypes in mice fed with methionine-choline-deficient (MCD) diet and choline-deficient ethionine-supplemented (CDE) diet, respectively. In summary, Ex-4 elicits protective functions against NAFLD and obesity-associated HCC through cAMP-PKA-EGFR-STAT3 signaling, suggesting its administration as a novel approach to reduce HCC risk in diabetic patients.

Topics: Animals; Cyclic AMP; Diabetes Mellitus, Type 2; Disease Models, Animal; ErbB Receptors; Exenatide; Glucagon-Like Peptide-1 Receptor; Humans; Hyperglycemia; Liver Neoplasms; Liver Neoplasms, Experimental; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Peptides; Risk Factors; Signal Transduction; STAT3 Transcription Factor; Venoms; Xenograft Model Antitumor Assays

To estimate the long-term cost-effectiveness of exenatide twice daily vs insulin glargine once daily as add-on therapy to oral antidiabetic agents (OADs) for Chinese patients with type 2 diabetes (T2DM).. The Cardiff Diabetes Model was used to simulate disease progression and estimate the long-term effects of exenatide twice daily vs insulin glargine once daily. Patient profiles and treatment effects required for the model were obtained from literature reviews (English and Chinese databases) and from a meta-analysis of 8 randomized controlled trials comparing exenatide twice daily with insulin glargine once daily add-on to OADs for T2DM in China. Medical expenditure data were collected from 639 patients with T2DM (aged ≥18 years) with and without complications incurred between January 1, 2014 and December 31, 2015 from claims databases in Shandong, China. Costs (2014 Chinese Yuan [¥]) and benefits were estimated, from the payers' perspective, over 40 years at a discount rate of 3%. A series of sensitivity analyses were performed.. Patients on exenatide twice daily + OAD had a lower predicted incidence of most cardiovascular and hypoglycaemic events and lower total costs compared with those on insulin glargine once daily + OAD. A greater number of quality-adjusted life years (QALYs; 1.94) at a cost saving of ¥117 706 gained was associated with exenatide twice daily vs insulin glargine once daily. (i.e. cost saving of ¥60 764/QALY) per patient.. In Chinese patients with T2DM inadequately controlled by OADs, exenatide twice daily is a cost-effective add-on therapy alternative to insulin glargine once daily, and may address the problem of an excess of medical needs resulting from weight gain and hypoglycaemia in T2DM treatment.

Topics: Administration, Oral; Cardiovascular Diseases; China; Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Cardiomyopathies; Direct Service Costs; Drug Administration Schedule; Drug Therapy, Combination; Exenatide; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Incidence; Incretins; Injections, Subcutaneous; Insulin Glargine; Middle Aged; Models, Economic; Peptides; Quality of Life; Randomized Controlled Trials as Topic; Venoms

The range of glycated haemoglobin (HbA1c) responses and characteristics associated with above-average response to exenatide twice daily and once weekly were examined. Data were pooled from 8 exenatide-twice-daily and 5 exenatide-once-weekly studies. A baseline HbA1c-corrected measure of change in HbA1c after 24 weeks identified high, average and low responses. Multiple linear regression and multivariate generalized estimating equation models identified factors associated with high response. Among 2355 participants (exenatide twice daily, n = 1414; exenatide once weekly, n = 941), baseline HbA1c correlated with change in HbA1c (P < .0001). Across baseline HbA1c levels, the 25th to 75th percentile of HbA1c change ranged from -0.3% to -3.2% with exenatide twice daily and from -0.5% to -3.6% with exenatide once weekly. Asian ethnicity and older age were significantly associated with high response to exenatide twice daily; no factors were significantly associated with response to exenatide once weekly. These data provide clinically useful information for estimating the likelihood that, depending on baseline HbA1c, an individual can achieve HbA1c goals. The association between Asian ethnicity, age and high response to exenatide twice daily may relate to the specific effects of exenatide twice daily on postprandial glucose.

Topics: Age Factors; Asian People; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Resistance; Exenatide; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Incretins; Middle Aged; Peptides; Postprandial Period; Randomized Controlled Trials as Topic; Reproducibility of Results; Venoms

The two major obstacles in the successful transplantation of islets for diabetes treatment are inadequate supply of insulin-producing tissue and immune rejection. Induction of the differentiation of human bone marrow-derived mesenchymal stem cells (hMSCs) into insulin-producing cells (IPCs) for autologous transplantation may alleviate those limitations.. hMSCs were isolated and induced to differentiate into IPCs through a three-stage differentiation protocol in a defined media with high glucose, nicotinamide, and exendin-4. The physiological characteristics and functions of IPCs were then evaluated. Next, about 3 × 10(6) differentiated cells were transplanted into the renal sub-capsular space of streptozotocin (STZ)-induced diabetic nude mice. Graft survival and function were assessed by immunohistochemistry, TUNEL staining and measurements of blood glucose levels in the mice.. The differentiated IPCs were characterized by Dithizone (DTZ) positive staining, expression of pancreatic β-cell markers, and human insulin secretion in response to glucose stimulation. Moreover, 43% of the IPCs showed L-type Ca2+ channel activity and similar changes in intracellular Ca2+ in response to glucose stimulation as that seen in pancreatic β-cells in the process of glucose-stimulated insulin secretion. Transplantation of functional IPCs into the renal subcapsular space of STZ-induced diabetic nude mice ameliorated the hyperglycemia. Immunofluorescence staining revealed that transplanted IPCs sustainably expressed insulin, c-peptide, and PDX-1 without apparent apoptosis in vivo.. IPCs derived from hMSCs in vitro can ameliorate STZ-induced diabetic hyperglycemia, which indicates that these hMSCs may be a promising approach to overcome the limitations of islet transplantation.

Topics: Adipocytes; Animals; Apoptosis; Bone Marrow Cells; Calcium Channels; Cell Differentiation; Chondrocytes; Culture Media; Diabetes Mellitus, Experimental; Dithizone; Exenatide; Glucose; Humans; Hyperglycemia; Insulin; Insulin-Secreting Cells; Karyotyping; Male; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Mice, Inbred BALB C; Mice, Nude; Niacinamide; Osteogenesis; Peptides; Phenotype; Streptozocin; Transplantation, Heterologous; Venoms

Admission hyperglycemia is an independent risk factor for poor outcome of ischemic stroke. Amelioration of hyperglycemia by insulin has not been shown to improve the poststroke outcome. Glucagon-like peptide 1 receptor agonists, which modulate glucose levels by stimulating insulin secretion, have been shown to exert cytoprotective effects by inhibiting inflammation and oxidative stress. This study aimed to evaluate whether the glucagon-like peptide 1 receptor agonist exendin-4 could reduce glucose levels and exert protective effects after acute focal ischemia in hyperglycemic mice.. Hyperglycemia was induced by intraperitoneal injection of dextrose 15 minutes before transient middle cerebral artery occlusion was performed for 60 minutes using an intraluminal thread. We assessed 4 groups: (1) normal glucose (vehicle control), (2) induced hyperglycemia, (3) induced hyperglycemia with insulin treatment, and (4) induced hyperglycemia with exendin-4 treatment. Neurovascular injuries in brains from each group were evaluated 24 hours and 7 days post ischemia.. Hyperglycemia significantly increased infarct volume (36.3±1.20 versus 26.9±1.28; P<0.001), brain edema (P<0.05), and hemorrhagic transformation compared with control (P<0.001). This increase in infarct volume was associated with increased blood-brain barrier disruption and matrix metalloproteinase-9 activation. Exendin-4, but not insulin, attenuated matrix metalloproteinase-9 activation, proinflammatory cytokine (tumor necrosis factor-α) release, and biomarkers of oxidative stress and showed significant inhibition of infarct growth at 24 hours (23.6±0.97 versus 36.3±1.20; P<0.001) and at 7 days after ischemia (21.0±0.92 versus 29.3±1.41; P<0.001).. Treatment with exendin-4 could be a potentially useful therapeutic option for treatment of acute ischemic stroke with transient hyperglycemia.

Topics: Animals; Blood-Brain Barrier; Brain Ischemia; Disease Models, Animal; Exenatide; Hyperglycemia; Hypoglycemic Agents; Infarction, Middle Cerebral Artery; Male; Matrix Metalloproteinase 9; Mice, Inbred C57BL; Peptides; Venoms

A defining characteristic of type 1 diabetes mellitus (T1DM) pathophysiology is pancreatic β-cell death and dysfunction, resulting in insufficient insulin secretion to properly control blood glucose levels. Treatments that promote β-cell replication and survival, thus reversing the loss of β-cell mass, while also preserving β-cell function, could lead to a real cure for T1DM. The α-subunit of the heterotrimeric Gz protein, Gαz, is a tonic negative regulator of adenylate cyclase and downstream cAMP production. cAMP is one of a few identified signaling molecules that can simultaneously have a positive impact on pancreatic islet β-cell proliferation, survival, and function. The purpose of our study was to determine whether mice lacking Gαz might be protected, at least partially, from β-cell loss and dysfunction after streptozotocin treatment. We also aimed to determine whether Gαz might act in concert with an activator of the cAMP-stimulatory glucagon-like peptide 1 receptor, exendin-4 (Ex4). Without Ex4 treatment, Gαz-null mice still developed hyperglycemia, albeit delayed. The same finding held true for wild-type mice treated with Ex4. With Ex4 treatment, Gαz-null mice were protected from developing severe hyperglycemia. Immunohistological studies performed on pancreas sections and in vitro apoptosis, cytotoxicity, and survival assays demonstrated a clear effect of Gαz signaling on pancreatic β-cell replication and death; β-cell function was also improved in Gαz-null islets. These data support our hypothesis that a combination of therapies targeting both stimulatory and inhibitory pathways will be more effective than either alone at protecting, preserving, and possibly regenerating β-cell mass and function in T1DM.

Topics: Adenylyl Cyclases; Animals; Blood Glucose; Cell Line, Tumor; Cell Proliferation; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Exenatide; Glucagon-Like Peptide 1; Glucose; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Mice; Mice, Inbred C57BL; Mice, Knockout; Pancreas; Peptides; Rats; Signal Transduction; Streptozocin; Venoms

The guideline for the management of new-onset diabetes after transplantation recommends metformin (MET) as a first-line drug, and addition of a second-line drug is needed to better control of hyperglycemia. We tested the effect of addition of a dipeptidyl peptidase IV (DPP IV) inhibitor to MET on sirolimus (SRL)-induced diabetes mellitus (DM). In animal model of SRL-induced DM, MET treatment improved pancreatic islet function (blood glucose level and insulin secretion) and attenuated oxidative stress and apoptotic cell death. Addition of a DPP IV inhibitor to MET improved these parameters more than MET alone. An in vitro study showed that SRL treatment increased pancreas beta cell death and production of reactive oxygen species (ROS), and pretreatment of ROS inhibitor, or p38MAPK inhibitor effectively decreased SRL-induced islet cell death. Exendin-4 (EXD), a substrate of DPP IV or MET significantly improved cell viability and decreased ROS production compared with SRL treatment, and combined treatment with the 2 drugs improved both parameters. At the subcellular level, impaired mitochondrial respiration by SRL were partially improved by MET or EXD and much improved further after addition of EXD to MET. Our data suggest that addition of a DPP IV inhibitor to MET decreases SRL-induced oxidative stress and improves mitochondrial respiration. This finding provides a rationale for the combined use of a DPP IV inhibitor and MET in treating SRL-induced DM.

Topics: Animals; Apoptosis; Cell Survival; Diabetes Mellitus, Experimental; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Drug Therapy, Combination; Exenatide; Hyperglycemia; Islets of Langerhans; Male; Metformin; Mitochondria; Oxidative Stress; Peptides; Piperidones; Pyrimidines; Rats, Sprague-Dawley; Reactive Oxygen Species; Sirolimus; Venoms

Impaired insulin signaling pathway in the brain in type 2 diabetes (T2D) is a risk factor for Alzheimer disease (AD). Glucagon-like peptide-1 (GLP-1) and its receptor agonist are widely used for treatment of T2D. Here we studied whether the effects of exendin-4 (EX-4), a long-lasting GLP-1 receptor agonist, could reduce the risk of AD in T2D.. Type 2 diabetes rats were injected with EX-4 for 28 consecutive days. Blood glucose and insulin levels, as well as GLP-1 and insulin in cerebrospinal fluid, were determined during the experiment. The phosphorylation level of tau at individual phosphorylation sites, the activities of phosphatidylinositol 3 kinase/protein kinase B (PI3K/AKT), and glycogen synthase kinase-3β (GSK-3β) were analyzed with Western blots.. The levels of phosphorylated tau protein at site Ser199/202 and Thr217 level in the hippocampus of T2D rats were found to be raised notably and evidently decreased after EX-4 intervention. In addition, brain insulin signaling pathway was ameliorated after EX-4 treatment, and this result was reflected by a decreased activity of PI3K/AKT and an increased activity of GSK-3β in the hippocampus of T2D rats as well as a rise in PI3K/AKT activity and a decline in GSK-3β activity after 4 weeks intervention of EX-4.. These results demonstrate that multiple days with EX-4 appears to prevent the hyperphosphorylation of AD-associated tau protein due to increased insulin signaling pathway in the brain. These findings support the potential use of GLP-1 for the prevention and treatment of AD in individuals with T2D.

Topics: Alzheimer Disease; Animals; Blood Glucose; Blotting, Western; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide-1 Receptor; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hippocampus; Hyperglycemia; Insulin; Insulin Resistance; Male; Peptides; Phosphorylation; Proto-Oncogene Proteins c-akt; Rats, Sprague-Dawley; Receptors, Glucagon; Signal Transduction; tau Proteins; Venoms

Glucagon-like peptide-1 receptor (GLP-1R) is closely associated with the onset of diabetes and its complications. However, its roles in diabetic retinopathy are unknown. Retinal pigment epithelial (RPE) cells are a crucial component of the outer blood-retina barrier and their death is related to the progression of diabetic retinopathy. Thus, we examined the pathophysiological role of GLP-1R in RPE cell apoptosis. We found that GLP-1R expression was lower in the isolated neuroretina and RPE cells of streptozotocin-treated rats than in vehicle-treated rats. High-glucose treatment also decreased GLP-1R expression in a human RPE cell line (ARPE-19 cells). GLP-1R was silenced in ARPE-19 cells, in order to elucidate the pathophysiological roles of GLP-1R. This increased intracellular reactive oxygen species (ROS) generation and activated p53-mediated Bax promoter and endoplasmic reticulum (ER) stress signaling. We also found that GLP-1R knockdown-mediated p53 expression was regulated by ER stress. Interestingly, antioxidant treatment and peroxiredoxin 1 (Prx1) overexpression attenuated GLP-1R knockdown-induced ER stress signaling and p53 expression. Finally, to confirm that GLP-1R activation has protective effects, ARPE-19 cells were treated with exendin-4, a synthetic GLP-1R agonist. This attenuated high-glucose-induced ROS generation, ER stress signaling, and p53 expression. Collectively, these results indicated that hyperglycemia decreases GLP-1R expression in RPE cells. Such a decrease generates intracellular ROS, which increases ER stress-mediated p53 expression, and subsequently causes apoptosis by increasing Bax promoter activity. Our data suggested that regulation of GLP-1R expression is a promising approach for the treatment of diabetic retinopathy.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Cell Line; Cells, Cultured; Down-Regulation; Endoplasmic Reticulum Stress; Exenatide; Gene Knockdown Techniques; Gene Silencing; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hyperglycemia; Intracellular Space; Models, Biological; Peptides; Promoter Regions, Genetic; Rats; Reactive Oxygen Species; Receptors, Glucagon; Retinal Pigment Epithelium; RNA, Small Interfering; Signal Transduction; Streptozocin; Tumor Suppressor Protein p53; Venoms

Exenatide once weekly, an injectable glucagon-like peptide-1 receptor agonist, has been shown to reduce A1C, fasting glucose, and body weight in patients with type 2 diabetes. Exenatide 2.0 mg is dispersed in poly-(D,L-lactide-co-glycolide) polymer microspheres, which require resuspension in aqueous diluent before subcutaneous injection. A single-use, dual-chamber pen was developed to improve the convenience of exenatide once weekly delivery and tested following Food and Drug Administration (FDA) guidance.. Design development goals were established, and validation tests (dose accuracy, torque/force requirements, usability, and ease-of-use) were performed. Dose accuracy was tested under a variety of conditions. After 10 exploratory studies in 329 patients, the final design's usability and ease-of-use were tested in untrained health care practitioners (HCPs; n = 16) and untrained/trained patients (n = 30/17). Usability testing evaluated completion of multiple setup, dose preparation, and injection steps. Ease-of-use impression was assessed using a scale of 1-7 (1 = very difficult, 7 = very easy).. The dual-chamber pen successfully met development goals and delivered target volume (650 µL ± 10%) under tested conditions (mean 644.7-649.3 µL), with torque and force requirements below prespecified maximum values. In the final user study, most participants (≥87%) correctly completed pen setup, dose preparation, and injection steps. Mean ease-of-use scores were 5.8, 6.3, and 6.5 out of 7 in untrained HCPs, untrained patients, and trained patients, respectively.. With self-education or minimal training, participants accurately and precisely suspended, mixed, and delivered exenatide-containing microspheres using the dual-chamber pen with high ease-of-use scores. The dual-chamber pen was FDA-approved in February 2014.

Topics: Adult; Device Approval; Diabetes Mellitus, Type 2; Drug Administration Schedule; Equipment Design; Exenatide; Humans; Hyperglycemia; Hypoglycemic Agents; Injections, Subcutaneous; Lactic Acid; Microspheres; Peptides; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Reproducibility of Results; Risk Factors; Self Administration; Syringes; Torque; United States; United States Food and Drug Administration; Venoms

Islet transplantation has become a viable clinical treatment, but is still compromised by long-term graft failure. Exendin-4, a glucagon-like peptide 1 receptor agonist, has in clinical studies been shown to improve insulin secretion in islet transplanted patients. However, little is known about the effect of exendin-4 on other metabolic parameters. We therefore aimed to determine what influence exendin-4 would have on revascularized minimal human islet grafts in a state of graft failure in terms of glucose metabolism, body weight, lipid levels and graft survival. Introducing the bilateral, subcapsular islet transplantation model, we first transplanted diabetic mice with a murine graft under the left kidney capsule sufficient to restore normoglycemia. After a convalescent period, we performed a second transplantation under the right kidney capsule with a minimal human islet graft and allowed for a second recovery. We then performed a left-sided nephrectomy, and immediately started treatment with exendin-4 with a low (20μg/kg/day) or high (200μg/kg/day) dose, or saline subcutaneously twice daily for 15 days. Blood was sampled, blood glucose and body weight monitored. The transplanted human islet grafts were collected at study end point and analyzed. We found that exendin-4 exerts its effect on failing human islet grafts in a bell-shaped dose-response curve. Both doses of exendin-4 equally and significantly reduced blood glucose. Glucagon-like peptide 1 (GLP-1), C-peptide and pro-insulin were conversely increased. In the course of the treatment, body weight and cholesterol levels were not affected. However, immunohistochemistry revealed an increase in beta cell nuclei count and reduced TUNEL staining only in the group treated with a low dose of exendin-4 compared to the high dose and control. Collectively, these results suggest that exendin-4 has a potential rescue effect on failing, revascularized human islets in terms of lowering blood glucose, maintaining beta cell numbers, and improving metabolic parameters during hyperglycemic stress.

Topics: Animals; Apoptosis; Blood Glucose; C-Peptide; Cell Count; Diabetes Mellitus, Experimental; Exenatide; Fasting; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Graft Survival; Humans; Hyperglycemia; Insulin; Insulin Secretion; Insulin-Secreting Cells; Islets of Langerhans; Islets of Langerhans Transplantation; Male; Mice, Inbred BALB C; Models, Animal; Peptides; Venoms

With the availability of a smaller mixing pen, mass marketing of less stable medications is possible. Bidureon is one such medication, and the properties of its pen are discussed along with the prospects for future mixing pens.

Topics: Diabetes Mellitus, Type 2; Exenatide; Humans; Hyperglycemia; Injections, Subcutaneous; Peptides; Syringes; Venoms

Maternal obesity leads to increased adiposity, hyperlipidaemia and glucose intolerance in offspring. The analogue of glucagon-like peptide-1, exendin-4 (Ex-4), has been shown to induce weight loss in both adolescence and adulthood. We hypothesised that, in rats, daily injection of Ex-4 would reduce body fat and improve metabolic disorders in offspring from obese dams, especially those consuming a high-fat diet (HFD).. Female Sprague Dawley rats were fed chow or an HFD for 5 weeks before mating, and throughout gestation and lactation. At postnatal day 20, male pups from HFD-fed mothers were weaned onto chow or HFD and those from chow-fed mothers were fed chow. Within each dietary group, half of the pups were injected with Ex-4 (15 μg/kg/day i.p.) for 6 weeks, while the other half received saline.. Maternal obesity alone or combined with postweaning HFD consumption led to increased adiposity, hyperinsulinaemia, hyperlipidaemia, inflammation and impaired regulation of hypothalamic appetite regulators by glucose in offspring, while glucose intolerance was only observed in HFD-fed rats from obese dams. Ex-4 injection significantly reduced adiposity, hyperlipidaemia and insulin resistance in HFD-fed rats from obese dams. It also restored glucose tolerance and the lipid-lowering effect of blood glucose. However, Ex-4 did not change hypothalamic appetite regulation or the response of appetite regulators to hyperglycaemia. Liver and adipose inflammatory cytokine expression was significantly reduced by Ex-4.. Ex-4 reversed the detrimental impact of maternal obesity on lipid and glucose metabolism in offspring regardless of diet, supporting its potential application in reducing metabolic disorders in high-risk populations.

Topics: Adiposity; Animals; Animals, Newborn; Appetite Regulation; Biomarkers; Blood Glucose; Body Weight; Diet, High-Fat; Exenatide; Female; Glucose Tolerance Test; Hyperglycemia; Hypoglycemic Agents; Hypothalamus; Insulin Resistance; Male; Maternal Nutritional Physiological Phenomena; Overnutrition; Peptides; Pregnancy; Rats; Rats, Sprague-Dawley; Venoms; Weaning

The effects of exenatide on glycemic control, lipid metabolism, blood pressure, and gastrointestinal symptoms were investigated in obese Japanese patients with type 2 diabetes mellitus. Twenty-six outpatients were enrolled and administered 5 μg of exenatide twice daily. If there was insufficient weight loss and/or insufficient improvement in glycemic control, the dose was increased to 10 μg twice daily. Follow-up was continued until the 12th week of administration. Hemoglobin A1c, glycoalbumin, fasting plasma glucose, body weight, fasting serum C-peptide, serum lipids, blood pressure, and pulse rate were measured before and after the observation period. In the initial phase of exenatide therapy, each patient received a diary to record gastrointestinal symptoms. During treatment with exenatide, hemoglobin A1c decreased significantly and serum C-peptide increased significantly. Body weight, low-density lipoprotein cholesterol, and systolic blood pressure decreased significantly. Nausea was the most frequent gastrointestinal symptom and occurred in 16 patients. Its onset was noted at a mean of 1.7 h after injection, the mean duration was 1.1 h, and it continued for a mean of 9.3 days after the initiation of administration. Patients with nausea showed a significant decrease in hemoglobin Alc, glycoalbumin, or body weight compared with those without nausea. These findings suggest that a more marked improvement in metabolic parameters by exenatide can be partly dependent on the manifestation of gastrointestinal symptoms.

Topics: Adult; Aged; Anti-Obesity Agents; Anticholesteremic Agents; Antihypertensive Agents; Body Mass Index; Diabetes Mellitus, Type 2; Exenatide; Female; Follow-Up Studies; Gastrointestinal Agents; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Injections, Subcutaneous; Japan; Male; Middle Aged; Nausea; Obesity; Peptides; Venoms; Weight Loss

The ubiquitin/proteasome system (UPS), a major cellular protein degradation machinery, plays key roles in the regulation of many cell functions. Glucotoxicity mediated by chronic hyperglycaemia is detrimental to the function and survival of pancreatic beta cells. The aim of our study was to determine whether proteasome dysfunction could be involved in beta cell apoptosis in glucotoxic conditions, and to evaluate whether such a dysfunction might be pharmacologically corrected. Therefore, UPS activity was measured in GK rats islets, INS-1E beta cells or human islets after high glucose and/or UPS inhibitor exposure. Immunoblotting was used to quantify polyubiquitinated proteins, endoplasmic reticulum (ER) stress through CHOP expression, and apoptosis through the cleavage of PARP and caspase-3, whereas total cell death was detected through histone-associated DNA fragments measurement. In vitro, we found that chronic exposure of INS-1E cells to high glucose concentrations significantly decreases the three proteasome activities by 20% and leads to caspase-3-dependent apoptosis. We showed that pharmacological blockade of UPS activity by 20% leads to apoptosis in a same way. Indeed, ER stress was involved in both conditions. These results were confirmed in human islets, and proteasome activities were also decreased in hyperglycemic GK rats islets. Moreover, we observed that a high glucose treatment hypersensitized beta cells to the apoptotic effect of proteasome inhibitors. Noteworthily, the decreased proteasome activity can be corrected with Exendin-4, which also protected against glucotoxicity-induced apoptosis. Taken together, our findings reveal an important role of proteasome activity in high glucose-induced beta cell apoptosis, potentially linking ER stress and glucotoxicity. These proteasome dysfunctions can be reversed by a GLP-1 analog. Thus, UPS may be a potent target to treat deleterious metabolic conditions leading to type 2 diabetes.

Topics: Animals; Apoptosis; Caspase 3; Cells, Cultured; Endoplasmic Reticulum Stress; Exenatide; Gene Expression; Glucose; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin-Secreting Cells; Male; Peptides; Poly(ADP-ribose) Polymerases; Proteasome Endopeptidase Complex; Proteasome Inhibitors; Proteolysis; Rats; Signal Transduction; Transcription Factor CHOP; Ubiquitin; Venoms

The renal osmoregulatory function was studied in patients with type 2 diabetes mellitus (DM). The renal response to water loading (0.7% b.w.) and simultaneous exenatide (byetta) injection (5 microg) exhibited variation and was dependent on the degree of hyperglycemia. Effective solute-free water excretion was observed in patients with well-controlled DM (HbAlc 6.0 +/- 0.1%), in which CH20 changed from -0.67 +/- 0.2 mL/min to 0.72 +/- 0.2 mL/min. This reaction was absent in patients with poorly controlled DM (HbAlc 8.8 +/- 0.6%) and the process of solute-free water reabsorption prevailed: -CH20 = -1.06 +/- 0.1 mL/min in control period vs. -0.99 +/- 0.1 mL/min after treatment. Thus, byetta increases the efficiency of osmoregulation and accelerates the excretion of excess water in patients with compensated carbohydrate metabolism.

Topics: Adult; Aged; Diabetes Mellitus, Type 2; Diuresis; Exenatide; Female; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Kidney; Male; Middle Aged; Osmoregulation; Peptides; Venoms; Water; Water-Electrolyte Balance

To assess the feasibility of transdermal delivery of exenatide (EXT) using low-molecular-weight sodium hyaluronate (HA) dissolving microneedles (MNs) patches for type 2 diabetes mellitus therapy.. Micromold casting method was used to fabricate EXT-loaded dissolving MNs. The characteristics of prepared MNs including mechanical strength, in vitro/in vivo insertion capacity, dissolution profile and storage stability were then investigated. Finally, the in vivo pharmacokinetics and hypoglycemic effects were compared with traditional subcutaneous (SC) injection.. EXT-loaded dissolving MNs made of HA possessed sufficient mechanical strength and the strength could be weakened as the water content increases. The EXT preserved its pharmacological activity during fabrication and one-month storage. With the aid of spring-operated applicator, dissolving MNs could be readily penetrated into the skin in vitro/in vivo, and then rapidly dissolved to release encapsulated drug within 2 min. Additionally, transepidermal water loss (TEWL) determinations showed that skin's barrier properties disrupted by MNs recovered within 10-12 h. Transdermal pharmacokinetics and antidiabetic effects studies demonstrated that fabricated EXT MNs induced comparable efficacy to SC injection.. Our rapidly dissolving MNs patch appears to an excellent, painless alternative to conventional SC injection of EXT, and this minimally invasive device might also be suitable for other biotherapeutics.

Topics: Animals; Drug Stability; Exenatide; Glucose Tolerance Test; Hyaluronic Acid; Hyperglycemia; Hypoglycemic Agents; Male; Needles; Peptides; Rats; Rats, Sprague-Dawley; Transdermal Patch; Venoms; Water Loss, Insensible

Long-acting glucagon-like peptide-1 receptor (GLP-1R) agonists have both glucose- and weight-lowering effects. The brain is poised to mediate both of these actions since GLP-1Rs are present in key areas known to control weight and glucose. Although some research has been performed on the effects of exendin-4 in the brain, little data exists on the central effects of liraglutide, a long-acting GLP-1R agonist with much closer structural homology to native GLP-1. In lean, Long-Evans rats, we found that direct intra-third cerebroventricular (i3vt) administration of 0.26 nmol liraglutide caused a 50% reduction in food intake. However, exendin-4 produced the same reduction in food intake with 10-fold greater potency (0.02 nmol). These data are supported by similar c-Fos immunoreactivity in the hypothalamic paraventricular nuclei by exendin-4 as compared to liraglutide despite differing doses. The anorectic effects of both drugs were blocked with i3vt pre-treatment of a GLP-1R competitive antagonist, exendin(9-39), indicating that both drugs required the GLP-1R for their effects. Exendin-4, and not liraglutide, caused hyperglycemia when given i3vt prior to an oral glucose tolerance test, although liraglutide did not lower glucose. Thus, these data show that GLP-1R agonists have differing anorectic potencies in the CNS, which may account for some of their clinical differences. Additionally, we show here that the glucose lowering properties of acute administration of GLP-1R agonists are not accounted for by their central effects.

Topics: Animals; Anorexia; Eating; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hyperglycemia; Hypoglycemic Agents; Hypothalamus; Liraglutide; Male; Peptides; Rats; Rats, Long-Evans; Receptors, Glucagon; Venoms

Topics: Exenatide; Female; Humans; Hyperglycemia; Hypoglycemic Agents; Male; Myocardial Infarction; Myocardium; Peptides; Venoms

Glucagon-like peptide-1 (GLP-1), as a member of the incretin family, has a role in glucose homeostasis, its receptors distributed throughout the body, including the heart. The aim was to investigate cardiac lesions following diabetes induction, and the potential effect of GLP-1 on this type of lesions and the molecular mechanism driving this activity. Adult male rats were classified into: normal, diabetic, 4-week high-dose exenatide-treated diabetic rats, 4-week low-dose exenatide-treated diabetic rats, and 1-week exenatide-treated diabetic rats. The following parameters were measured: in blood: glucose, insulin, lactate dehydrogenase (LDH), total creatine kinase (CK), creatine kinase MB isoenzyme (CK-MB), and CK-MB relative index; in cardiac tissue: lipid peroxide (LPO) and some antioxidant enzymes. The untreated diabetic group displayed significant increases in blood level of glucose, LDH, and CK-MB, and cardiac tissue LPO, and a significant decrease in cardiac tissue antioxidant enzymes. GLP-1 supplementation in diabetic rats definitely decreased the hyperglycemia and abolished the detrimental effects of diabetes on the cardiac tissue. The effect of GLP-1 on blood glucose and on the heart also appeared after a short supplementation period (1 week). It can be concluded that GLP-1 has beneficial effects on diabetes-induced oxidative cardiac tissue damage, most probably via its antioxidant effect directly acting on cardiac tissue and independent of its hypoglycemic effect.

Topics: Animals; Antioxidants; Blood Glucose; Creatine Kinase; Diabetes Complications; Diabetes Mellitus, Experimental; Exenatide; Glucagon-Like Peptide 1; Glucose; Heart; Hyperglycemia; Incretins; Insulin; L-Lactate Dehydrogenase; Lipid Peroxides; Male; Oxidative Stress; Peptides; Rats; Rats, Sprague-Dawley; Venoms

The hepatoportal area is an important glucohomeostatic metabolic sensor, sensing hypoglycemia, hyperglycemia, and hormones such as glucagon-like peptide-1 (GLP-1). We have reported previously that activation of hepatoportal sensors by intraportal infusion of glucose and GLP-1 or by subcutaneous administration of GLP-1 receptor activator exenatide and of intraportal glucose improved glycemia independent of corresponding changes in pancreatic hormones. It is not clear whether this effect is mediated via the portal vein (PV) or by direct action on the liver itself. To test whether receptors in the PV mediate exenatide's beneficial effect on glucose tolerance, we performed 1) paired oral glucose tolerance tests (OGTT) with and without exenatide and 2) intravenous glucose tolerance tests before and after PV denervation in canines. Denervation of the portal vein affected oral glucose tolerance; post-denervation (POST-DEN) OGTT glucose and insulin AUC were 50% higher than before denervation (P = 0.01). However, portal denervation did not impair exenatide's effect to improve oral glucose tolerance (exenatide effect: 48 ± 12 mmol·l⁻¹·min before vs. 64 ± 26 mmol·l⁻¹·min after, P = 0.67). There were no changes in insulin sensitivity or secretion during IVGTTs. Portal vein sensing might play a role in controlling oral glucose tolerance during physiological conditions but not in pharmacological activation of GLP-1 receptors by exenatide.

Topics: Animals; Biomarkers; Blood Glucose; Crosses, Genetic; Denervation; Exenatide; Glucagon-Like Peptide-1 Receptor; Glucose Clamp Technique; Glucose Intolerance; Glucose Tolerance Test; Hyperglycemia; Hyperinsulinism; Hypoglycemic Agents; Injections, Subcutaneous; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Male; Peptides; Portal Vein; Receptors, Glucagon; Tyrosine 3-Monooxygenase; Venoms

Glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP4) inhibitors improve glucose tolerance by still incompletely understood mechanisms. Each class of antihyperglycemic drugs has also been proposed to increase pancreatitis risk. Here, we compare systematically the effects of two widely-used GLP-1 analogues, liraglutide and exendin-4, and the DPP4 inhibitor, sitagliptin, in the mouse.. C57BL6 mice were maintained for 131 days on a normal diet (ND) or a diet comprising 60% fat (HFD) before measurements of fasting blood glucose and insulin, and intraperitoneal glucose tolerance. Beta- and alpha- cell volume, and Reg3b immunoreactivity, were measured by immunohistochemical analysis of pancreatic slices.. Whereas liraglutide (200 µg/kg) and exendin-4 (10 µg/kg) treatment reduced body weight and/or improved glucose tolerance, sitagliptin (10 mg/kg) was without effect on either parameter. Liraglutide caused a sharp reduction in beta-cell mass in both ND and HFD mice, whereas exendin-4 exerted no effect. By contrast, sitagliptin unmasked an action of high fat diet to increase beta-cell mass. Reg3B positive area was augmented by all three agents in normal chow-fed mice, whilst sitagliptin and exendin-4, but not liraglutide, affected this parameter in HFD animals. Correspondingly sitagliptin, but not the GLP-1 analogues, increased circulating amylase levels in ND and HFD mice.. Liraglutide improves glucose tolerance in the mouse whilst exerting relatively modest effects on pancreatitis risk. Conversely, exendin-4 and sitagliptin, at doses which exert, respectively, minor or no effects on metabolic parameters, lead to signs of pancreatitis.

Topics: Animals; Blood Glucose; Body Weight; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Liraglutide; Male; Mice; Mice, Inbred C57BL; Pancreas; Pancreatitis; Peptides; Sitagliptin Phosphate; Venoms

Leptin may reduce pancreatic lipid deposition, which increases with progression of obesity and can impair β-cell function. The insulinotropic effect of glucagon-like peptide-1 (GLP-1) and the efficacy of GLP-1 receptor agonist are reduced associated with impaired β-cell function. In this study, we examined whether leptin could restore the efficacy of exenatide, a GLP-1 receptor agonist, in type 2 diabetes with increased adiposity. We chronically administered leptin (500 μg·kg⁻¹·day⁻¹) and/or exenatide (20 μg·kg⁻¹·day⁻¹) for 2 wk in a mouse model of type 2 diabetes with increased adiposity induced by streptozotocin and high-fat diet (STZ/HFD mice). The STZ/HFD mice exhibited hyperglycemia, overweight, increased pancreatic triglyceride level, and reduced glucose-stimulated insulin secretion (GSIS); moreover, the insulinotropic effect of exenatide was reduced. However, leptin significantly reduced pancreatic triglyceride level, and adding leptin to exenatide (LEP/EX) remarkably enhanced GSIS. These results suggested that the leptin treatment restored the insulinotropic effect of exenatide in the mice. In addition, LEP/EX reduced food intake, body weight, and triglyceride levels in the skeletal muscle and liver, and corrected hyperglycemia to a greater extent than either monotherapy. The pair-feeding experiment indicated that the marked reduction of pancreatic triglyceride level and enhancement of GSIS by LEP/EX occurred via mechanisms other than calorie restriction. These results suggest that leptin treatment may restore the insulinotropic effect of exenatide associated with the reduction of pancreatic lipid deposition in type 2 diabetes with increased adiposity. Combination therapy with leptin and exenatide could be an effective treatment for patients with type 2 diabetes with increased adiposity.

Topics: Adiposity; Animals; Anti-Obesity Agents; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Drug Implants; Drug Synergism; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Secretion; Leptin; Male; Mice, Inbred C57BL; Overweight; Pancreas; Peptides; Recombinant Proteins; Streptozocin; Triglycerides; Venoms

Incretins improve glucose metabolism through multiple mechanisms. It remains unclear whether direct hepatic effects are an important part of exenatide's (Ex-4) acute action. Therefore, the objective of this study was to determine the effect of intraportal delivery of Ex-4 on hepatic glucose production and uptake. Fasted conscious dogs were studied during a hyperglycemic clamp in which glucose was infused into the hepatic portal vein. At the same time, portal saline (control; n = 8) or exenatide was infused at low (0.3 pmol·kg⁻¹·min⁻¹, Ex-4-low; n = 5) or high (0.9 pmol·kg⁻¹·min⁻¹, Ex-4-high; n = 8) rates. Arterial plasma glucose levels were maintained at 160 mg/dl during the experimental period. This required a greater rate of glucose infusion in the Ex-4-high group (1.5 ± 0.4, 2.0 ± 0.7, and 3.7 ± 0.7 mg·kg⁻¹·min⁻¹ between 30 and 240 min in the control, Ex-4-low, and Ex-4-high groups, respectively). Plasma insulin levels were elevated by Ex-4 (arterial: 4,745 ± 428, 5,710 ± 355, and 7,262 ± 1,053 μU/ml; hepatic sinusoidal: 14,679 ± 1,700, 15,341 ± 2,208, and 20,445 ± 4,020 μU/ml, 240 min, area under the curve), whereas the suppression of glucagon was nearly maximal in all groups. Although glucose utilization was greater during Ex-4 infusion (5.92 ± 0.53, 6.41 ± 0.57, and 8.12 ± 0.54 mg·kg⁻¹·min⁻¹), when indices of hepatic, muscle, and whole body glucose uptake were expressed relative to circulating insulin concentrations, there was no indication of insulin-independent effects of Ex-4. Thus, this study does not support the notion that Ex-4 generates acute changes in hepatic glucose metabolism through direct effects on the liver.

Topics: Animals; Consciousness; Dogs; Exenatide; Female; Glucose; Hyperglycemia; Hypoglycemic Agents; Infusions, Intravenous; Insulin; Lactic Acid; Liver; Male; Peptides; Portal Vein; Venoms

The glucokinase activators improve the fasting as well as postprandial glucose control and are important investigational drugs for the treatment of diabetes. However, recent studies have implicated that continuous activation of glucokinase with a small molecule activator can increase hepatic triglycerides and the long term glucose control is not achieved. In this study, we investigated the effect of combination of glucokinase activator (GKA, Piragliatin) with GLP-1 receptor agonist exendin-4 (Ex-4) in male db/db mice. Twelve weeks combination treatment in the db/db mice resulted in a significant decrease in body weight gain, food consumption, random glucose and %HbA1c. The decrease in serum glucose and %HbA1c in combination group was more profound and significantly different than that of individual treatment (GKA or Ex-4) group. GKA treatment increased hepatic triglycerides, whereas combination of Ex-4 with GKA attenuated hepatic steatosis. The combination of GKA with Ex-4 reduced the hepatic lipid accumulation, improved the insulin sensitivity, and reduced hepatic glucose production in db/db mice. Overall, our data indicate that combination of GKA and GLP-1 receptor agonist Ex-4 improves glucose homeostasis, shows antiobesity activity, without causing harmful side effects like fatty liver.

Topics: Animals; Benzeneacetamides; Body Weight; Drug Synergism; Eating; Enzyme Activation; Exenatide; Fatty Liver; Glucokinase; Glucose; Glycogen; Homeostasis; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Liver; Male; Mice; Mice, Inbred C57BL; Peptides; Venoms

We will investigate the effects of exenatide on vascular endothelial injury and nitrooxidative stress in hyperglycemia both in vivo and in vitro and explore the role of nitrooxidative stress in endothelium-protective action of exenatide. Healthy male Wistar rats were randomly divided into 4 groups: control, diabetes mellitus (DM) model, low dose of exenatide treatment, and high dose of exenatide treatment. In vitro study showed that, compared with control group, the DM rats exhibited a lowered endothelium-dependent relaxation and damaged structural integrity of thoracic aortas, and there was a significant increase in plasma nitrotyrosine concentration. These parameters were improved after treatment with either low dose or high dose of exenatide for 45 days. In vitro study showed that exendin-4 (the active ingredient of exenatide) attenuated HUVECs injury induced by high glucose, with improving cell viability and attenuating cell apoptosis. Exendin-4 also significantly alleviated the increased malondialdehyde (MDA), nitrotyrosine content, and inducible nitric oxide synthase (iNOS) expression induced by high glucose in HUVECs. In conclusion, this study demonstrates that exenatide treatment can alleviate the vascular endothelial injury, as well as attenuating the nitrooxidative stress in hyperglycemia, implying that the endothelium-protective effect of exenatide might be related to the reduction of nitrooxidative stress.

Topics: Animals; Aorta, Thoracic; Cardiovascular Abnormalities; Diabetes Mellitus, Experimental; Endothelium, Vascular; Exenatide; Hyperglycemia; Male; Nitric Oxide; Nitric Oxide Synthase Type II; Oxidative Stress; Peptides; Rats; Venoms

Glucocorticoid-induced hyperglycemia is common in patients with or without known diabetes mellitus. Exenatide, a glucagon-like peptide-1 receptor agonist, improves glycemic control without causing weight gain or hypoglycemia and is currently widely used in patients with type 2 diabetes mellitus. We herein report four cases of patients with type 2 diabetes with worsened glycemic control due to glucocorticoids who were successfully treated with exenatide administration.

Topics: Adult; Aged; Aged, 80 and over; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Administration Schedule; Exenatide; Female; Follow-Up Studies; Glucocorticoids; Humans; Hyperglycemia; Hypoglycemic Agents; Injections, Subcutaneous; Insulin; Male; Middle Aged; Peptides; Risk Assessment; Sampling Studies; Treatment Outcome; Venoms

Hyperglycemia-induced cardiomyocyte apoptosis contributes to diabetic cardiomyopathy. Glucagon-like peptide-1 (Glp1) receptor (Glp1r) agonists improve cardiac function and survival in response to ischemia-reperfusion and myocardial infarction. The present studies assessed whether Glp1r activation exerts direct cardioprotective effects in response to hyperglycemia. Treatment with the Glp1r agonist Exendin-4 attenuated apoptosis in neonatal rat ventricular cardiomyocytes cultured in high (33 mM) glucose. This protective effect was mimicked by the cAMP inducer forskolin. The Exendin-4 protective effect was blocked by the Glp1r antagonist Exendin(9-39) or the PKA antagonist H-89. Exendin-4 also protected cardiomyocytes from hydrogen peroxide (H2O2)-induced cell death. Cardiomyocyte protection by Exendin-4 was not due to reduced reactive oxygen species levels. Instead, Exendin-4 treatment reduced endoplasmic reticulum (ER) stress, demonstrated by decreased expression of glucose-regulated protein-78 (GRP78) and CCAT/enhancer-binding homologous protein (CHOP). Reduced ER stress was not due to activation of the unfolded protein response, indicating that Exendin-4 directly prevents ER stress. Exendin-4 treatment selectively protected cardiomyocytes from thapsigargin- but not tunicamycin-induced death. This suggests that Exendin-4 attenuates thapsigargin-mediated inhibition of the sarco/endoplasmic reticulum Ca(2+) ATPase-2a (SERCA2a). High glucose attenuates SERCA2a function by reducing SERCA2a mRNA and protein levels, but Exendin-4 treatment prevented this reduction. Exendin-4 treatment also enhanced phosphorylation of the SERCA2a regulator phospholamban (PLN), which would be expected to stimulate SERCA2a activity. In sum, Glp1r activation attenuates high glucose-induced cardiomyocyte apoptosis in association with decreased ER stress and markers of enhanced SERCA2a activity. These findings identify a novel mechanism whereby Glp1-based therapies could be used as treatments for diabetic cardiomyopathy.

Topics: Animals; Apoptosis; Calcium-Binding Proteins; Cells, Cultured; Colforsin; Diabetic Cardiomyopathies; Endoplasmic Reticulum Stress; Enzyme Activation; Exenatide; Glucagon-Like Peptide-1 Receptor; Glucose; Heat-Shock Proteins; HSP70 Heat-Shock Proteins; Hydrogen Peroxide; Hyperglycemia; Hypoglycemic Agents; Isoquinolines; Membrane Proteins; Myocytes, Cardiac; Oxidative Stress; Peptide Fragments; Peptides; Phosphorylation; Protein Kinase Inhibitors; Rats; Receptors, Glucagon; RNA, Messenger; Sarcoplasmic Reticulum Calcium-Transporting ATPases; Sulfonamides; Thapsigargin; Transcription Factor CHOP; Tunicamycin; Unfolded Protein Response; Venoms

Acute insulin secretion determines the efficiency of glucose clearance. Moreover, impaired acute insulin release is characteristic of reduced glucose control in the prediabetic state. Incretin hormones, which increase β-cell cAMP, restore acute-phase insulin secretion and improve glucose control. To determine the physiological role of the cAMP-dependent protein kinase (PKA), a mouse model was developed to increase PKA activity specifically in the pancreatic β-cells. In response to sustained hyperglycemia, PKA activity potentiated both acute and sustained insulin release. In contrast, a glucose bolus enhanced acute-phase insulin secretion alone. Acute-phase insulin secretion was increased 3.5-fold, reducing circulating glucose to 58% of levels in controls. Exendin-4 increased acute-phase insulin release to a similar degree as PKA activation. However, incretins did not augment the effects of PKA on acute-phase insulin secretion, consistent with incretins acting primarily via PKA to potentiate acute-phase insulin secretion. Intracellular calcium signaling was unaffected by PKA activation, suggesting that the effects of PKA on acute-phase insulin secretion are mediated by the phosphorylation of proteins involved in β-cell exocytosis. Thus, β-cell PKA activity transduces the cAMP signal to dramatically increase acute-phase insulin secretion, thereby enhancing the efficiency of insulin to control circulating glucose.

Topics: Animals; Crosses, Genetic; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Enzyme Induction; Exenatide; Glucose Clamp Technique; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Secretion; Insulin-Secreting Cells; Kinetics; Mice; Mutant Proteins; Patch-Clamp Techniques; Peptides; Phosphorylation; Protein Processing, Post-Translational; Protein Subunits; Second Messenger Systems; Up-Regulation; Venoms

Impaired cardiac microvascular function contributes to cardiovascular complications in diabetes. Glucagon-like peptide-1 (GLP-1) exhibits potential cardioprotective properties in addition to its glucose-lowering effect. This study was designed to evaluate the impact of GLP-1 on cardiac microvascular injury in diabetes and the underlying mechanism involved. Experimental diabetes was induced using streptozotocin in rats. Cohorts of diabetic rats received a 12-week treatment of vildagliptin (dipeptidyl peptidase-4 inhibitor) or exenatide (GLP-1 analog). Experimental diabetes attenuated cardiac function, glucose uptake, and microvascular barrier function, which were significantly improved by vildagliptin or exenatide treatment. Cardiac microvascular endothelial cells (CMECs) were isolated and cultured in normal or high glucose medium with or without GLP-1. GLP-1 decreased high-glucose-induced reactive oxygen species production and apoptotic index, as well as the levels of NADPH oxidase such as p47(phox) and gp91(phox). Furthermore, cAMP/PKA (cAMP-dependent protein kinase activity) was increased and Rho-expression was decreased in high-glucose-induced CMECs after GLP-1 treatment. In conclusion, GLP-1 could protect the cardiac microvessels against oxidative stress, apoptosis, and the resultant microvascular barrier dysfunction in diabetes, which may contribute to the improvement of cardiac function and cardiac glucose metabolism in diabetes. The protective effects of GLP-1 are dependent on downstream inhibition of Rho through a cAMP/PKA-mediated pathway.

Topics: AMP-Activated Protein Kinases; Animals; Cardiotonic Agents; Cells, Cultured; Cyclic AMP; Diabetic Angiopathies; Diabetic Cardiomyopathies; Disease Models, Animal; Endothelium, Vascular; Exenatide; Glucagon-Like Peptide 1; Heart Ventricles; Hyperglycemia; Hypoglycemic Agents; Male; Microvessels; Oxidative Stress; Peptides; Random Allocation; Rats; Rats, Sprague-Dawley; rho GTP-Binding Proteins; Second Messenger Systems; Venoms

The incretin hormones, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) and cholecystokinin (CCK) are gastrointestinal peptides with important physiological effects. However, rapid enzymatic degradation results in short-lived biological actions.. This study has examined metabolic actions of exendin-4, GIP[mPEG] and a novel CCK-8 analogue, (pGlu-Gln)-CCK-8 as enzymatically stable forms of GLP-1, GIP and CCK, respectively.. All peptides significantly (p < 0.01-p < 0.001) stimulated insulin secretion from BRIN BD11 cells, and acute in vivo experiments confirmed prominent antihyperglycaemic and insulinotropic responses to GLP-1 or GIP receptor activation in normal mice. Twice daily injection of (pGlu-Gln)-CCK-8 alone and in combination with exendin-4 or GIP[mPEG] in high fat-fed mice significantly decreased accumulated food intake (p < 0.05-p < 0.01), body weight gain (p < 0.05-p < 0.01) and improved (p < 0.05) insulin sensitivity in high fat-fed mice. However, there was no evidence for superior effects compared to (pGlu-Gln)-CCK-8 alone. Combined treatment of (pGlu-Gln)-CCK-8 and exendin-4 resulted in significantly (p < 0.05) lowered circulating glucose levels and improved (p < 0.05) intraperitoneal glucose tolerance. These effects were superior to either treatment regime alone but not associated with altered insulin concentrations. A single injection of (pGlu-Gln)-CCK-8, or combined with exendin-4, significantly (p < 0.05) lowered blood glucose levels 24 h post injection in untreated high fat-fed mice.. This study highlights the potential of (pGlu-Gln)-CCK-8 alone and in combination with incretin hormones for the treatment of type 2 diabetes.

Topics: Animals; Anti-Obesity Agents; Appetite Regulation; Cell Line; Diabetes Mellitus, Type 2; Diet, High-Fat; Drug Therapy, Combination; Exenatide; Gastric Inhibitory Polypeptide; Hyperglycemia; Hypoglycemic Agents; Incretins; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Male; Mice; Mice, Inbred Strains; Obesity; Peptides; Rats; Sincalide; Time Factors; Venoms

Diabetes is a strong risk factor for premature and severe stroke. The GLP-1R (glucagon-like peptide-1 receptor) agonist Ex-4 (exendin-4) is a drug for the treatment of T2D (Type 2 diabetes) that may also have neuroprotective effects. The aim of the present study was to determine the efficacy of Ex-4 against stroke in diabetes by using a diabetic animal model, a drug administration paradigm and a dose that mimics a diabetic patient on Ex-4 therapy. Furthermore, we investigated inflammation and neurogenesis as potential cellular mechanisms underlying the Ex-4 efficacy. A total of seven 9-month-old Type 2 diabetic Goto–Kakizaki rats were treated peripherally for 4 weeks with Ex-4 at 0.1, 1 or 5 μg/kg of body weight before inducing stroke by transient middle cerebral artery occlusion and for 2–4 weeks thereafter. The severity of ischaemic damage was measured by evaluation of stroke volume and by stereological counting of neurons in the striatum and cortex. We also quantitatively evaluated stroke-induced inflammation, stem cell proliferation and neurogenesis. We show a profound anti-stroke efficacy of the clinical dose of Ex-4 in diabetic rats, an arrested microglia infiltration and an increase of stroke-induced neural stem cell proliferation and neuroblast formation, while stroke-induced neurogenesis was not affected by Ex-4. The results show a pronounced anti-stroke, neuroprotective and anti-inflammatory effect of peripheral and chronic Ex-4 treatment in middle-aged diabetic animals in a preclinical setting that has the potential to mimic the clinical treatment. Our results should provide strong impetus to further investigate GLP-1R agonists for their neuroprotective action in diabetes, and for their possible use as anti-stroke medication in non-diabetic conditions.

Topics: Animals; Brain Ischemia; Cell Proliferation; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Exenatide; Glucagon-Like Peptide-1 Receptor; Hyperglycemia; Male; Microglia; Neurogenesis; Neuroprotective Agents; Peptides; Rats; Receptors, Glucagon; Stroke; Stroke Volume; Venoms

BACKGROUND AND PURPOSE Preclinical pharmacology of 3-iodothyronamine (T1AM), an endogenous derivative of thyroid hormones, indicates that it is a rapid modulator of rodent metabolism and behaviour. Since T1AM undergoes rapid enzymatic degradation, particularly by MAO, we hypothesized that the effects of T1AM might be altered by inhibition of MAO. EXPERIMENTAL APPROACH We investigated the effects of injecting T1AM (i.c.v.) on (i) feeding behaviour, hyperglycaemia and plasma levels of thyroid hormones and (ii) T1AM systemic bioavailability, in overnight fasted mice, under control conditions and after pretreatment with the MAO inhibitor clorgyline. T1AM (1.3, 6.6, 13, 20 and 26 µg·kg(-1) ) or vehicle were injected i.c.v. in fasted male mice not pretreated or pretreated i.p. with clorgyline (2.5 mg·kg(-1) ). Glycaemia was measured by a glucorefractometer, plasma triiodothyronine (fT3) by a chemiluminescent immunometric assay, c-fos activation immunohistochemically and plasma T1AM by HPLC coupled to tandem-MS. KEY RESULTS T1AM, 1.3 µg·kg(-1) , produced a hypophagic effect (-24% vs. control) and reduced c-fos activation. This dose showed systemic bioavailability (0.12% of injected dose), raised plasma glucose levels and reduced peripheral insulin sensitivity (-33% vs. control) and plasma fT3 levels. These effects were not linearly related to the dose injected. Clorgyline pretreatment strongly increased the systemic bioavailability of T1AM and prevented the hyperglycaemia and reduction in fT3 induced by T1AM. CONCLUSIONS AND IMPLICATIONS T1AM induces central and peripheral effects including hyperglycaemia and a reduction in plasma fT3 levels in fasted mice. These effects critically depend on the concentration of T1AM or its metabolites in target organs.

Topics: Animals; Blood Glucose; Clorgyline; Eating; Exenatide; Fasting; Hyperglycemia; Hypoglycemic Agents; Hypothalamus; Insulin Resistance; Male; Mice; Monoamine Oxidase Inhibitors; Pancreas; Peptides; Proto-Oncogene Proteins c-fos; Thyroid Gland; Thyroid Hormones; Thyronines; Venoms

Exendin-4 is a stable peptide agonist of GLP-1 receptor that exhibits insulinotropic actions. Some in vivo studies indicated insulin-independent glucoregulatory actions of exendin-4. That finding prompted us to evaluate effects of exendin-4 on liver glucose metabolism. Acute and chronic treatment of exendin-4 resulted in increased hepatic glucokinase activity in db/db mice but not in lean C57 mice. The stimulatory effect of exendin-4 on glucokinase activity was abrogated by exendin 9-39, a GLP-1 antagonist. Exposure of hepatocytes isolated from db/db mice to exendin-4 elicited a rapid increase in cAMP, which was synergized by IBMX, an inhibitor of cAMP degradation. The GLP-1 antagonist, exendin 9-39, has abolished the cAMP generating effects of exendin-4 as well. Furthermore, chronic treatment of exendin-4 in streptozotocin-treated C57 mice resulted in restoration of hepatic glycogen, an indicator of improved glucose metabolism, without apparent changes in serum insulin levels. In conclusion, exendin-4 increased glucokinase enzyme protein and activity in liver via a mechanism parallel to and independent of insulin. Exendin-4-induced increase in hepatic glucokinase activity is more pronounced in the presence of hepatic insulin resistance. This beneficial effect of exendin-4 on liver glucokinase activity may be mediated by GLP-1 receptor.

Topics: Animals; Cyclic AMP; Diabetes Mellitus, Experimental; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucokinase; Glucose; Glycogen; Hepatocytes; Hyperglycemia; Insulin; Insulin Resistance; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Peptides; Receptors, Glucagon; Venoms

The development of type 2 diabetes is accompanied by a progressive decline in β-cell mass and function. Vildagliptin, a dipeptidyl peptidase 4 inhibitor, is representative of a new class of antidiabetic agents that act through increasing the expression of glucagon-like peptide-1. The protective effect of this agent on β cells was studied in diabetic mice. Diabetic pancreatic β cell-specific C/EBPB transgenic (TG) mice exhibit decreased β-cell mass associated with increased apoptosis, decreased proliferation, and aggravated endoplasmic reticulum (ER) stress. Vildagliptin was orally administered to the TG mice for a period of 24 weeks, and the protective effects of this agent on β cells were examined, along with the potential molecular mechanism of protection. Vildagliptin ameliorated hyperglycemia in TG mice by increasing the serum concentration of insulin and decreasing the serum concentration of glucagon. This agent also markedly increased β-cell mass, improved aggravated ER stress, and restored attenuated insulin/IGF1 signaling. A decrease in pancreatic and duodenal homeobox 1 expression was also observed in β cells isolated from our mouse model, but this was also restored by vildagliptin treatment. The expression of C/EBPB protein, but not mRNA, was unexpectedly downregulated in vildagliptin-treated TG mice and in exenatide-treated MIN6 cells. Activation of the GLP1 pathway induced proteasome-dependent C/EBPB degradation in β cells as the proteasome inhibitor MG132 restored the downregulation of C/EBPB protein by exenatide. Vildagliptin elicits protective effects on pancreatic β cells, possibly through C/EBPB degradation, and has potential for preventing the progression of type 2 diabetes.

Topics: Adamantane; Animals; Blood Glucose; CCAAT-Enhancer-Binding Protein-beta; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Endoplasmic Reticulum Stress; Exenatide; Gene Expression Regulation; Glucagon; Glucagon-Like Peptide 1; Hyperglycemia; Insulin; Insulin-Secreting Cells; Leupeptins; Mice; Mice, Transgenic; Nitriles; Peptides; Pyrrolidines; Venoms; Vildagliptin

Chronic hyperglycemia-associated inflammation plays critical roles in disease initiation and the progression of diabetic complications, including Alzheimer's disease (AD). However, the association of chronic hyperglycemia with acute inflammation of the central nervous system in the progression of AD still needs to be elucidated. In addition, recent evidence suggests that Glucagon-like peptide-1 receptor (GLP-1R) protects against neuronal damage in the brain. Therefore, the neuroprotective effects of the GLP-1R agonist exendin-4 (EX-4) against hyperglycemia/lipopolysaccharides (LPS) damage were also evaluated in this study.. Ten days after streptozotocin (STZ) or vehicle (sodium citrate) treatment in mice, EX-4 treatment (10 µg/kg/day) was applied to the mice before intrahippocampal CA1 injection of LPS or vehicle (saline) and continued for 28 days. This study examined the molecular alterations in these mice after LPS and EX4 application, respectively. The mouse cognitive function was evaluated during the last 6 days of EX-4 treatment. The results showed that the activation of NF-κB-related inflammatory responses induced cognitive dysfunction in both the hyperglycemic mice and the mice that received acute intrahippocampal LPS injection. Furthermore, acute intrahippocampal LPS injection exacerbated the impairment of spatial learning and memory through a strong decrease in monoaminergic neurons and increases in astrocytes activation and apoptosis in the hyperglycemic mice. However, EX-4 treatment protected against the cognitive dysfunction resulting from hyperglycemia or/and intrahippocampal LPS injection.. These findings reveal that both hyperglycemia and intrahippocampal LPS injection induced cognitive dysfunction via activation of NF-κB-related inflammatory responses. However, acute intrahippocampal LPS injection exacerbated the progression of cognitive dysfunction in the hyperglycemic mice via a large increase in astrocytes activation-related responses. Furthermore, EX-4 might be considered as a potential adjuvant entity to protect against neurodegenerative diseases.

Topics: Animals; Apoptosis; Astrocytes; Blood Glucose; Cognition; Cognition Disorders; Cyclooxygenase 1; Cyclooxygenase 2; Exenatide; Hippocampus; Hyperglycemia; Hypoglycemic Agents; Injections; Insulin; Interleukin-1beta; Leukocyte Common Antigens; Lipopolysaccharides; Male; Membrane Proteins; Memory; Mice; Mice, Inbred C57BL; Neurons; NF-kappa B; Peptides; Spatial Behavior; Streptozocin; Superoxide Dismutase; Up-Regulation; Venoms

The incidence of diabetes mellitus is increasing among companion animals. This disease has similar characteristics in both humans and animals. Diabetes is frequently identified as an independent risk factor for infections associated with increased mortality. In the present study, homozygous diabetic (db/db) mice were infected with Listeria (L.) monocytogenes and then treated with the anti-diabetic drug exendin-4, a glucagon-like peptide 1 analogue. In aged db/db mice, decreased CD11b(+) macrophage populations with higher lipid content and lower phagocytic activity were observed. Exendin-4 lowered high lipid levels and enhanced phagocytosis in macrophages from db/db mice infected with L. monocytogenes. Exendin-4 also ameliorated obesity and hyperglycemia, and improved ex vivo bacteria clearance by macrophages in the animals. Liver histology examined during L. monocytogenes infection indicated that abscess formation was much milder in exendin-4-treated db/db mice than in the control animals. Moreover, mechanistic studies demonstrated that expression of ATP binding cassette transporter 1, a sterol transporter, was higher in macrophages isolated from the exendin-4-treated db/db mice. Overall, our results suggest that exendin-4 decreases the risk of infection in diabetic animals by modifying the interaction between intracellular lipids and phagocytic macrophages.

Topics: Age Factors; Animals; ATP Binding Cassette Transporter 1; ATP-Binding Cassette Transporters; Blood Chemical Analysis; Cholesterol; Diabetes Mellitus, Type 2; Dyslipidemias; Exenatide; Female; Hyperglycemia; Hypoglycemic Agents; Injections, Intraperitoneal; Lipid Metabolism; Listeria monocytogenes; Listeriosis; Macrophages; Mice; Obesity; Peptides; Phagocytosis; Venoms

Glucagon-like peptide-1 (GLP-1), a gut incretin hormone secreted from L cells, and a GLP-1 receptor agonist, exendin-4 (Ex-4) has been shown to be cardioprotective and could exert beneficial effects through its anti-inflammatory property. However, the mechanism remains unclear. The purpose of this study was to investigate whether Ex-4 could ameliorate myocardial cell injury by inhibiting high mobility group box 1 (HMGB1) expression under high glucose condition. Neonatal rat ventricular myocytes were prepared and then cultured with high glucose and different concentration of Ex-4. Lactate dehydrogenase (LDH), creatine kinase (CK), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), malondialdehyde (MDA) and superoxide dismutase (SOD) were measured. HMGB1 expression was assessed by western blotting. Ex-4 significantly inhibited the increase in LDH, CK, TNF-α, IL-1β and MDA levels induced by high glucose, especially at the 1 and 10 nM concentrations as well as suppressed the decrease in SOD level. Meanwhile, HMGB1 expression was markedly increased after 12 h of hyperglycaemia (P < 0.05), which was significantly inhibited by Ex-4, especially at the 1 and 10 nM concentrations (P < 0.05). The present study suggested that Ex-4 could reduce high glucose-induced cardiocytes injury, which may be associated with the inhibition of HMGB1 expression.

Topics: Animals; Creatine Kinase; Cytoprotection; Exenatide; Glucagon-Like Peptide-1 Receptor; HMGB1 Protein; Hyperglycemia; Interleukin-1beta; L-Lactate Dehydrogenase; Malondialdehyde; Myocytes, Cardiac; Peptides; Rats; Rats, Sprague-Dawley; Receptors, Glucagon; Superoxide Dismutase; Tumor Necrosis Factor-alpha; Venoms

Prolonged exposure of pancreatic beta-cells to elevated levels of glucose and fatty acids adversely affects insulin secretion and gene expression.. To examine whether the GLP-1 agonist exenatide or the inhibitor of the GLP-1-degrading enzyme dipeptidyl peptidase 4 (DPP-4) sitagliptin rescue insulin gene expression in rats infused for 72h with glucose+Intralipid, independently from their glucose-lowering action.. Wistar rats were infused alternatively with glucose or Intralipid for cycles of 4h each for a total of 72h. The animals received exenatide (5microg/kg/day IV) or sitagliptin (5mg/kg/day IV) continuously starting 4 days prior to and continuing throughout the 3-day infusion period.. Plasma glucose, fatty acids, insulin and C-peptide levels were unaffected by exenatide or sitagliptin treatment during the infusion period. Insulin mRNA levels increased in response to the glucose infusion, but this increase was abolished in islets from rats receiving glucose+Intralipid. Neither exenatide nor sitagliptin administration rescued insulin mRNA in glucose+Intralipid infused rats.. Neither a GLP-1 agonist nor a DPP-4 inhibitor, at doses that do not alter blood glucose levels, prevented the inhibition of insulin gene expression in this in vivo model of glucolipotoxicity.

Topics: Analysis of Variance; Animals; Blood Glucose; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Eating; Exenatide; Fat Emulsions, Intravenous; Gene Expression; Glucagon-Like Peptide 1; Glucose; Hyperglycemia; Hyperlipidemias; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Lipids; Male; Peptides; Pyrazines; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sitagliptin Phosphate; Triazoles; Venoms

Activation of glucagon-like peptide-1 (GLP-1) receptors improves insulin sensitivity and induces vasodilatation and diuresis. AC3174 is a peptide analogue with pharmacologic properties similar to the GLP-1 receptor agonist, exenatide. Hypothetically, chronic AC3174 treatment could attenuate salt-induced hypertension, cardiac morbidity, insulin resistance, and renal dysfunction in Dahl salt-sensitive (DSS) rats.. DSS rats were fed low salt (LS, 0.3% NaCl) or high salt (HS, 8% NaCl) diets. HS rats were treated with vehicle, AC3174 (1.7 pmol/kg/min), or GLP-1 (25 pmol/kg/min) for 4 weeks via subcutaneous infusion. Other HS rats received captopril (150 mg/kg/day) or AC3174 plus captopril.. HS rat survival was improved by all treatments except GLP-1. Systolic blood pressure (SBP) was lower in LS rats and in GLP-1, AC3174, captopril, or AC3174 plus captopril HS rats than in vehicle HS rats (p < 0.05). AC3174 plus captopril attenuated the deleterious effects of high salt on posterior wall thickness, LV mass, and the ratio of LV mass to body weight (P < or = 0.05). In contrast, GLP-1 had no effect on these cardiovascular parameters. All treatments reduced LV wall stress. GLP-1, AC3174, captopril, or AC3174 plus captopril normalized fasting insulin and HOMA-IR (P < or = 0.05). AC3174, captopril, or AC3174 plus captopril improved renal function (P < or = 0.05). Renal morphology in HS rats was associated with extensive sclerosis. Monotherapy with AC3174, captopril, or GLP-1 attenuated renal damage. However, AC3174 plus captopril produced the most effective improvement.. Thus, AC3174 had antihypertensive, cardioprotective, insulin-sensitizing, and renoprotective effects in the DSS hypertensive rat model. Furthermore, AC3174 improved animal survival, an effect not observed with GLP-1.

Topics: Animals; Antihypertensive Agents; Blood Glucose; Captopril; Cardiotonic Agents; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Hyperglycemia; Hypertension, Renal; Hypoglycemic Agents; Insulin Resistance; Kidney Diseases; Male; Peptides; Rats; Rats, Inbred Dahl; Sodium Chloride, Dietary; Venoms

Recent progress suggests that exenatide, a mimetic of glucagon-like peptide-1 (GLP-1), might lower glycemia independent of increased beta-cell response or reduced gastrointestinal motility. We aimed to investigate whether exenatide stimulates glucose turnover directly in insulin-responsive tissues dependent or independent of insulinemia.. An intraportal glucose infusion clamp was used in dogs to measure glucose turnover to encompass potent activation of the putative glucose/GLP-1 sensor in the porto-hepatic circulation with exenatide. The modified glucose clamp was performed in the presence of postprandial hyperinsulinemia and hyperglycemia with exenatide (20 microg) or saline injected at 0 min. Furthermore, the role of hyperglycemia versus hyperinsulinemia in exenatide-mediated glucose disposal was studied.. With hyperinsulinemia and hyperglycemia, exenatide produced a significant increase in total glucose turnover by approximately 30%, as indicated by portal glucose infusion rate (saline 15.9 +/- 1.6 vs. exenatide 20.4 +/- 2.1 mg x kg(-1) x min(-1), P < 0.001), resulting from increased whole-body glucose disposal (R(d), approximately 20%) and increased net hepatic uptake of exogenous glucose ( approximately 80%). Reducing systemic hyperglycemia to euglycemia, exenatide still increased total glucose turnover by approximately 20% (saline 13.2 +/- 1.9 vs. exenatide 15.6 +/- 2.1 mg x kg(-1) x min(-1), P < 0.05) in the presence of hyperinsulinemia, accompanied by smaller increments in R(d) (12%) and net hepatic uptake of exogenous glucose (45%). In contrast, reducing hyperinsulinemia to basal levels, exenatide-increased total glucose turnover was completely abolished despite hyperglycemia (saline 2.9 +/- 0.6 vs. exenatide 2.3 +/- 0.3 mg x kg(-1) x min(-1), P = 0.29).. Exenatide directly stimulates glucose turnover by enhancing insulin-mediated whole-body glucose disposal and increasing hepatic uptake of exogenous glucose, contributing to its overall action to lower postprandial glucose excursions.

Topics: Animals; Biological Transport; Dogs; Exenatide; Glucose; Hyperglycemia; Hypoglycemic Agents; Insulin; Liver; Male; Models, Biological; Peptides; Venoms

Current pancreatic islet transplantation protocols achieve remarkable short-term success, but long-term insulin independence remains elusive. Hypoxic and inflammatory insults cause substantial early posttransplant graft loss while allo/autoimmunity and immunosuppressive drug toxicity threaten long-term graft mass and function. Exendin-4 (Ex4) is a GLP-1 receptor agonist that promotes beta-cell proliferation, survival, and differentiation. To determine whether Ex-4 displays potential as a graft-supportive agent, we transplanted 500 murine islets under the kidney capsule of syngeneic or allogeneic streptozocin-treated recipient mice and immediately initiated daily treatment with vehicle or Ex4. Graft beta-cell proliferation, death, and vascularity were assessed at 1, 3, and 10 days after syngeneic islet transplantation. For allogeneic recipients, blood glucose and body weight were assessed until glycemic deterioration. Ex-4 did not promote graft beta-cell proliferation, reduce beta-cell death, or enhance graft vascularity over the first 10 days after syngeneic islet transplantation. A trend toward prolongation of posttransplant euglycemia was observed with Ex4 treatment in nonimmune-suppressed allograft recipients, but its use in this setting was associated with frequent, severe hypoglycemia over the first 2 posttransplant days. Our findings do not support a beneficial effect of Ex-4 on islet grafts during the critical early posttransplant period, further, they demonstrate a significant hypoglycemic potential of Ex-4 in the first days after islet transplantation in mice. Optimal application of GLP-1 receptor agonists for long-term proliferative and survival benefits in transplantation may require earlier intervention prior to and/or during islet isolation for peri-transplant cytoprotection and administration beyond the period of engraftment.

Topics: Animals; Blood Glucose; Cell Survival; Diabetes Mellitus, Experimental; Exenatide; Hyperglycemia; Hypoglycemic Agents; Insulin-Secreting Cells; Islets of Langerhans Transplantation; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Peptides; Subrenal Capsule Assay; Transplantation, Homologous; Transplantation, Isogeneic; Venoms

We examined the contributions of insulin secretion, glucagon suppression, splanchnic and peripheral glucose metabolism, and delayed gastric emptying to the attenuation of postprandial hyperglycemia during intravenous exenatide administration. Twelve subjects with type 2 diabetes (3 F/9 M, 44 +/- 2 yr, BMI 34 +/- 4 kg/m2, Hb A(1c) 7.5 +/- 1.5%) participated in three meal-tolerance tests performed with double tracer technique (iv [3-3H]glucose and oral [1-14C]glucose): 1) iv saline (CON), 2) iv exenatide (EXE), and 3) iv exenatide plus glucagon (E+G). Acetaminophen was given with the mixed meal (75 g glucose, 25 g fat, 20 g protein) to monitor gastric emptying. Plasma glucose, insulin, glucagon, acetaminophen concentrations and glucose specific activities were measured for 6 h post meal. Post-meal hyperglycemia was markedly reduced (P < 0.01) in EXE (138 +/- 16 mg/dl) and in E+G (165 +/- 12) compared with CON (206 +/- 15). Baseline plasma glucagon ( approximately 90 pg/ml) decreased by approximately 20% to 73 +/- 4 pg/ml in EXE (P < 0.01) and was not different from CON in E+G (81 +/- 2). EGP was suppressed by exenatide [231 +/- 9 to 108 +/- 8 mg/min (54%) vs. 254 +/- 29 to189 +/- 27 mg/min (26%, P < 0.001, EXE vs. CON] and partially reversed by glucagon replacement [247 +/- 15 to 173 +/- 18 mg/min (31%)]. Oral glucose appearance was 39 +/- 4 g in CON vs. 23 +/- 6 g in EXE (P < 0.001) and 15 +/- 5 g in E+G, (P < 0.01 vs. CON). The glucose retained within the splanchnic bed increased from approximately 36g in CON to approximately 52g in EXE and to approximately 60g in E+G (P < 0.001 vs. CON). Acetaminophen((AUC)) was reduced by approximately 80% in EXE vs. CON (P < 0.01). We conclude that exenatide infusion attenuates postprandial hyperglycemia by decreasing EGP (by approximately 50%) and by slowing gastric emptying.

Topics: Acetaminophen; Adult; Analgesics, Non-Narcotic; Blood Glucose; Diabetes Mellitus, Type 2; Exenatide; Female; Gastric Emptying; Glucagon; Glucose Tolerance Test; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Male; Middle Aged; Peptides; Postprandial Period; Triglycerides; Venoms

To evaluate the effect of exenatide on clinical parameters in obese patients with type 2 diabetes mellitus whose hyperglycemia is not adequately controlled despite treatment with oral hypoglycemic agents and insulin.. In this retrospective analysis, clinical progress of 52 obese patients with type 2 diabetes treated with exenatide, 5 mcg twice daily, in an outpatient setting was reviewed. Treatment initiation was between September and December 2005. Mean follow-up period was 26 weeks. Thirty-eight patients took exenatide regularly (Group A); 14 patients discontinued exenatide because of insurance, personal, or economic reasons (Group B). Measurements at baseline and at follow-up included body weight; blood pressure; and levels of hemoglobin A1c (HbA1c), high-sensitivity C-reactive protein (CRP), and plasma lipids. Insulin dosage requirements were assessed.. Mean body weight (+/- standard error of the mean) decreased by 6.46 +/- 0.8 kg (P<.001) in Group A and increased by 2.4 +/- 0.6 kg in Group B (P<001). In Group A, mean HbA1c decreased by 0.6 +/- 0.21% (P = .007), and the insulin dosage requirement decreased for rapid-acting and mixed insulins (P<.02). In Group A, means of the following parameters decreased: serum total cholesterol by 8.5 +/- 3.3% (P = .03), triglycerides by 26 +/- 7.6% (P = .01), systolic blood pressure by 9.2 +/- 3.3 mm Hg (P = .02), and high-sensitivity CRP by 34 +/- 14.3% (P = .05). These indices did not change in Group B.. Exenatide effectively treats obese patients with type 2 diabetes on insulin, leading to weight loss and reduction in levels of HbA1c, systolic blood pressure, triglycerides, and high-sensitivity CRP.

Topics: Blood Pressure; Body Weight; C-Reactive Protein; Cholesterol; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Female; Follow-Up Studies; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Male; Middle Aged; Obesity; Peptides; Retrospective Studies; Triglycerides; Venoms; Weight Loss

The insulin receptor substrate 2 (Irs2) branch of the insulin/insulin-like growth factor-signaling cascade prevents diabetes in mice because it promotes beta cell replication, function, and survival, especially during metabolic stress. Because exendin-4 (Ex4), a long acting glucagon-like peptide 1 receptor agonist, has similar effects upon beta cells in rodents and humans, we investigated whether Irs2 signaling was required for Ex4 action in isolated beta cells and in Irs2(-/-) mice. Ex4 increased cAMP levels in human islets and Min6 cells, which promoted Irs2 expression and stimulated Akt phosphorylation. In wild type mice Ex4 administered continuously for 28 days increased beta cell mass 2-fold. By contrast, Ex4 failed to arrest the progressive beta cell loss in Irs2(-/-) mice, which culminated in fatal diabetes; however, Ex4 delayed the progression of diabetes by 3 weeks by promoting insulin secretion from the remaining islets. We conclude that some short term therapeutic effects of glucagon-like peptide 1 receptor agonists can be independent of Irs2, but its long term effects upon beta cell growth and survival are mediated by the Irs2 branch of the insulin/insulin-like growth factor signaling cascade.

Topics: Animals; Blood Glucose; Cell Line; Cell Survival; Cyclic AMP; Dose-Response Relationship, Drug; Electrophoresis, Polyacrylamide Gel; Exenatide; Genotype; Glucagon-Like Peptide-1 Receptor; Glucose; Guinea Pigs; Humans; Hyperglycemia; Immunoblotting; Immunohistochemistry; Immunoprecipitation; Insulin; Insulin Receptor Substrate Proteins; Insulin Secretion; Insulin-Secreting Cells; Intracellular Signaling Peptides and Proteins; Islets of Langerhans; Mice; Mice, Transgenic; Models, Biological; Models, Chemical; Pancreas; Peptides; Phosphoproteins; Phosphorylation; Receptor, Insulin; Receptors, Glucagon; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Small Interfering; Signal Transduction; Time Factors; Venoms

Protein ingestion after injection of the glucagon-like peptide-1 receptor agonist Exendin-4 (Ex-4) causes hyperglycemia in rats. The objectives of this study were to determine the components of protein digestion responsible for this effect and to associate it with changes in the concentrations of other metabolites and hormones. Two experiments were conducted. In the first experiment, food-deprived rats were gavaged with intact whey (WP) or albumin protein, their hydrolysates, amino acid mixtures (1 g/2.5 ml), or water 5 min after injection of either PBS or Ex-4 (0.5 microg/rat). Tail vein blood was analyzed for glucose over 2 h. In the second experiment, food-deprived rats were gavaged with WP with or without Ex-4. Groups of conscious rats were killed by decapitation either before, or at selected times after gavage. Plasma concentrations of glucose, amino acids, free fatty acids (FFA), glycerol, insulin, glucagon, and leptin were measured. In experiment 1, blood glucose was higher when intact proteins and protein hydrolysates, but not amino acid mixtures, were given with than without Ex-4 (P < 0.05). In experiment 2, concentrations of glucose, FFA, and the ratio of tyrosine to branched-chain amino acid were higher (P < 0.01), but leptin and essential amino acid concentrations were lower (P < 0.05), and insulin, glucagon, and glycerol were similar when WP was given with or without Ex-4. We conclude that the hyperglycemia caused by the administration of Ex-4 concurrently with dietary protein arises from the action of peptides released during digestion and their interaction with Ex-4 in the regulation of glucose, fatty acid, and amino acid metabolism.

Topics: Amino Acids; Animals; Blood Glucose; Dietary Proteins; Drug Combinations; Exenatide; Glucagon-Like Peptide-1 Receptor; Hyperglycemia; Injections, Intraperitoneal; Male; Osmolar Concentration; Peptides; Protein Hydrolysates; Rats; Rats, Wistar; Receptors, Glucagon; Venoms

The purpose of this study is to ascertain the pharmacodynamic properties of exendin-4, a glucose-dependent insulinotropic agent, from plasma glucose and insulin concentration-time profiles following a 60-min intravenous infusion in healthy and type 2 diabetic subjects. Plasma glucose and insulin concentrations were obtained from a previous clinical study, whereby a hyperglycemic clamp was established and maintained in healthy (n = 7) and type 2 diabetic (n = 7) volunteers (plasma glucose raised 5.4 mM above fasting level). Exendin-4 was infused (0.15 pmol/kg/min) during the 2nd hour of a 5-h clamp. A physiological pharmacodynamic model was developed and fitted to individual glucose and insulin responses simultaneously. Because drug concentrations were unavailable, hypothetical pharmacokinetic driving functions were approximated during the modeling process and used to enhance a proportionality constant relating elevated glucose and the rate of second-phase insulin release. Exendin-4 infusions produced substantial insulin release in both subject populations that required higher glucose infusion rates to maintain stable hyperglycemia. Observed plasma glucose-insulin profiles were well characterized by the final pharmacodynamic model. Apparent exendin-4 elimination rate constants for healthy and diabetic subjects were similar (0.0386 +/- 0.0192 and 0.0460 +/- 0.0145 min(-1)). Capacity and sensitivity parameters of drug effect were 2-fold lower in diabetic subjects, but mean differences were not statistically significant. Simulations confirm that diabetic subjects exhibit a reduced capacity to enhance second-phase insulin release in response to exendin-4 compared with healthy subjects. Type 2 diabetic subjects demonstrate a significant response to exendin-4, but to a lesser extent than nondiabetic subjects, despite comparable measures of apparent drug exposure and efficacy.

Topics: Diabetes Mellitus, Type 2; Exenatide; Glucose; Homeostasis; Humans; Hyperglycemia; Insulin; Models, Biological; Peptides; Venoms

Treatment of overtly diabetic NOD mice with anti-lymphocyte serum (ALS), a polyclonal anti-T-cell antibody, abrogates autoimmunity and achieves partial clinical remission. Here we investigated whether the addition of exendin-4, a hormone that stimulates insulin secretion and beta-cell replication and differentiation, improves induction of remission by ALS. Transient treatment of overtly diabetic NOD mice with ALS and exendin-4 achieved complete remission in 23 of 26 mice (88%) within 75 days, accompanied by progressive normalization of glucose tolerance, improved islet histology, increased insulin content in the pancreas, and insulin release in response to a glucose challenge. Syngeneic islets transplanted into mice cured by treatment with ALS plus exendin-4 remained intact, and cotransfer of lymphocytes from cured mice delayed diabetes induction by adoptive transfer, suggesting the long-lasting presence of autoimmune regulatory cells. Although ALS alone also achieved reversal of diabetes, the frequency of remission was low (40%). No treatment or exendin-4 alone failed to produce remission. These results show that exendin-4 synergistically augments the remission-inducing effect of ALS. The addition of beta-cell growth factors, such as exendin-4, to immunotherapy protocols with anti-T-cell antibodies presents a potential novel approach to the cure of patients with new-onset type 1 diabetes.

Topics: Adoptive Transfer; Animals; Antilymphocyte Serum; Blood Glucose; Diabetes Mellitus, Type 1; Drug Administration Schedule; Drug Synergism; Drug Therapy, Combination; Exenatide; Female; Hyperglycemia; Immunosuppressive Agents; Insulin; Insulin Secretion; Mice; Mice, Inbred NOD; Mice, SCID; Pancreas; Pancreas Transplantation; Peptides; Venoms

NN2211 is a long-acting, metabolically stable glucagon-like peptide-1 (GLP-1) derivative designed for once daily administration in humans. NN2211 dose dependently reduced the glycemic levels in ob/ob mice, with antihyperglycemic activity still evident 24 h postdose. Apart from an initial reduction in food intake, there were no significant differences between NN2211 and vehicle treatment, and body weight was not affected. Histological examination revealed that beta-cell proliferation and mass were not increased significantly in ob/ob mice with NN2211, although there was a strong tendency for increased proliferation. In db/db mice, exendin-4 and NN2211 decreased blood glucose compared with vehicle, but NN2211 had a longer duration of action. Food intake was lowered only on day 1 with both compounds, and body weight was unaffected. beta-Cell proliferation rate and mass were significantly increased with NN2211, but with exendin-4, only the beta-cell proliferation rate was significantly increased. In conclusion, NN2211 reduced blood glucose after acute and chronic treatment in ob/ob and db/db mice and was associated with increased beta-cell mass and proliferation in db/db mice. NN2211 is currently in phase 2 clinical development.

Topics: Animals; Blood Glucose; Body Weight; Cell Division; Diabetes Mellitus, Type 2; Eating; Exenatide; Female; Glucagon; Glucagon-Like Peptide 1; Hyperglycemia; Insulin; Islets of Langerhans; Liraglutide; Mice; Mice, Inbred C57BL; Mice, Obese; Peptide Fragments; Peptides; Protein Precursors; Venoms

Glucagon-like peptide-1 ameliorates the symptoms of diabetes through stimulation of insulin secretion and enhancement of beta-cell mass. We have therefore investigated the effects of glucagon-like peptide-1 on the development of diabetes, using db/db mice as a model of Type II diabetes.. The potent glucagon-like peptide-1 analogue Exendin-4 or vehicle (control) was administered (i.p.; 1 nmol/kg) to obese 6-week old db/db mice daily for 14 days ( n=10).. By 8 weeks of age, control db/db mice developed hyperglycaemia (fasting: 10.4+/-0.5 mmol/l), hyperinsulinaemia and impaired glucose tolerance. However, Exendin-4 treatment prevented hyperglycaemia (fasting: 6.1+/-1.0 mmol/l, p<0.01), with reduced plasma insulin concentrations ( p<0.001) and improved glucose tolerance ( p<0.05). Peripheral insulin sensitivity was not affected. However, insulin release in vivo and in vitro from the perfused pancreas was improved by Exendin-4, as were pancreatic insulin concentrations (0.54+/-0.02 vs 0.32+/-0.01 micro g/mg protein, p<0.05). These changes occurred in conjunction with increased beta-cell mass (3.01+/-0.31 vs 2.22+/-0.22 mg, p<0.05) and proliferation (BrdU(+) beta-cells: 1.08+/-0.20 vs 0.47+/-0.11%, p<0.05), as well as decreased apoptosis (Tunel (+) beta-cells: 0.37+/-0.06 vs 1.20+/-0.21%). Western blot demonstrated increased expression of Akt1 (by fivefold, p<0.01) and p44 MAP kinase (by sixfold, p<0.01), and decreased activation of caspase-3 (by 30%, p<0.05).. Our results suggest that Ex4 treatment delays the onset of diabetes in 6-8 week old db/db mice, through a mechanism involving Akt1 and expansion of the functional beta-cell mass.

Topics: Animals; Apoptosis; Blood Glucose; Cell Division; Diabetes Mellitus; Diabetes Mellitus, Type 1; Exenatide; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hyperglycemia; Insulin; Islets of Langerhans; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Peptide Fragments; Peptides; Protein Precursors; Venoms