<prompt> Mechanism of action of the sulfonylureas isK ATP channel blockerNa ATP channel blockerCl ATP channel blockerCa ATP channel blocker.  <response>: Ans. is a i.e., K ATP channel blocker Sulfonylurease provoke a brisk release of insulin from pancreas. 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. 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. A minor action reducing glucagon secretion by increasing insulin and somatostatin release has been demonstrated. 