<prompt> Mechanism of action of sulfonylureas is -Insulin releaseAlpha glucosidase inhibitorPPAR g inhibitorInsulin sensitizer  <response>: Ans. is a i.e., Insulin release Sulfonvlureas act byo Sulfonylurease provoke a brisk release of insulin from pancreas.o They act on the so called Sulfonylurea receptors SUR1 on pancreatic b-cell membrane - cause depolarization by reducing conductance of ATP sensitive K channels. This enhances influx of Ca2 - degranulation.o They do not cause hypoglycemia in pancreatectomized animals and type 1 diabetes Presence of at least 30 of functional b-cells in essential for their action.o A minor action reducing glucagon secretion by increasing insulin and somatostatin release has been demonstrated,o Extrahepatic actionOn chronic administration they sensitize the target cells especially the liver to the action of insulin.On chronic administration their action on pancrease to release insuline declines due to down regulation of sulfonylurea receptors.But glycemic control is maintained due to extrahepatic action. 