Tolbutamide and gliclazide block the KATP channel Kir6.2/Sur1, causing membrane depolarization and stimulating insulin secretion in pancreatic beta cells. We examined the ability of the EPAC-selective cAMP analog 8-pCPT-29-O-Me-cAMP-AM to potentiate the action of these drugs and the mechanism that might account for it. Insulin secretion stimulated by both 200 mM tolbutamide and 20 mM gliclazide...

Tolbutamide and gliclazide block the K(ATP) channel K(ir)6.2/Sur1, causing membrane depolarization and stimulating insulin secretion in pancreatic beta cells. We examined the ability of the EPAC-selective cAMP analog 8-pCPT-2'-O-Me-cAMP-AM to potentiate the action of these drugs and the mechanism that might account for it. Insulin secretion stimulated by both 200 μM tolbutamide and 20 μM glicla...

The presence of elevated levels of glucose in blood during diabetes can lead to the non-enzymatic glycation of serum proteins such as human serum albumin (HSA). This study examined the changes that occur in binding of the sulfonylurea drug tolbutamide to HSA as the level of glycation for this protein was increased. High-performance affinity chromatography was used in this work along with column...

The hypoglycemic activity of tolbutamide and related compounds is well established; however, their mode of action is still debated. Several theories have been postulated (1-5). One of the most widely held is that tolbutamide stimulates the beta cells of the pancreas and the resulting insulin secretion produces the fall in blood sugar (1). The reported ineffectiveness of tolbutamide in depancrea...

The factors that influence functional coupling between the sulfonylurea receptor (SUR1) and Kir6.2 subunits of ATP-sensitive K+ (K+(ATP)) channels were studied in rat pancreatic beta-cells using patch clamp and microfluorometric techniques. Tolbutamide at 10 micromol/l inhibited K+(ATP) channels in association with occurrence of action currents, but further exposure of beta-cells to the drug fo...

Tolbutamide and gliclazide block the KATP channel Kir6.2/Sur1, causing membrane depolarization and stimulating insulin secretion in pancreatic beta cells. We examined the ability of the EPAC-selective cAMP analog 8-pCPT-29-O-Me-cAMP-AM to potentiate the action of these drugs and the mechanism that might account for it. Insulin secretion stimulated by both 200 mM tolbutamide and 20 mM gliclazide...

The effects of chronic tolbutamide treatment were examined in a diabetic animal model in which abnormal myocardial function and composition have previously been demonstrated. Eight diabetic dogs were given tolbutamide 250 mg/day orally and compared with seven untreated diabetics, five healthy dogs receiving tolbutamide, and eight normal controls. After one year, resting hemodynamic studies in t...

incubated in the presence of an excess of insulin (approx. 3pg of insulin/ml). Glucosestimulated membranes can release approx. 1500ng of insulin/ml before saturation of glucose-generated 8-granule-binding sites takes place at 60min incubation. When glucose 6-phosphate was added no further release of insulin took place despite the availability of 1.5pg of insulin/ml in 8-granules in the supernat...

The intravenous Na-tolbutamide test was done on various types of hypoglyce mia and the following conclusions were obtained: (1) Though very useful in the screening of hypoglycemia, the test is not always satisfactory for the differential diagnosis of various types of hypoglycemia. (2) The diagnosis of hypoglycemia by means of the Na-tolbutamide test is con sidered practically established when t...