A 53-yrs-old woman with type II diabetes mellitus is started on a sulfonylurea. Which of the following is one mechanism by which these drugs lower blood glucose levels? (AIPG 2009)
|A||Decrease insulin resistance by lowering body weight|
|B||Enhance renal excretion of glucose|
|C||Increase insulin synthesis|
|D||Release insulin from the pancreas|
a. Sulphonylurea mainly lower blood glucose levels by enhancing insulin release from the β cells of the pancreas. The mechanism involved binding to and blocking an ATP-sensitive K+ channel on β cell membranes.
b. This depolarizes the membrane, and resulting Ca2+ influx triggers insulin release.
c. The mechanistic dependence on insulin release, of course, explains why these drugs are ineffective in type 1 diabetes.