<prompt> A 30 year old male presents with recurrent attacks of sweating and dizziness. Fuher workup reveals low blood glucose levels with inappropriatlely elevated insulin and C-peptide levels. Imaging shows a lesion in the pancreas. He is diagnosed with insulinoma and given diazoxide. Which of the following is the mechanism of action of this drug?Opening of the sensitive K channelsClosing of the ATP sensitive K channelsIncrease in number of GLUT-4 receptorsOpening of the volatage sensitive Ca2 channels  <response>: Diazoxide acts by opening ATP sensitive K channels and causing a decrease in insulin secretion. Glucose enters beta cells of the pancreas GLUT-2 receptors. Once inside, it is phosphorylated by glucokinase rate-limiting step to glucose-6-phosphate which is oxidized to form adenosine triphosphateATP. This leads to opening volatge-gated calcium channels and Ca2 influx. This stimulates fusion of the insulin-containing vesicles with the cell membrane and secretion of insulin into the extracellular fluid by exocytosis. Diazoxide keeps the ATP sensitive K channels open, and prevents depolarisation and subsequent insulin release. Sulfonylureas cause closure of the ATP sensitive K channels, leading to an insulin secretion. REF: Guyton and Hall 13th edition PGno: 989 