Insulin secretion is/are increased by all except: (PGI Nov 2010)
Ans: C (VIP) (Ref.Guyton llth/968-69; Ganong 24th/441, 23rd/326 ]Insulin: Effect of Various Hormones Guyton nth/969Gastrointestinal Hormones. A mixture of several important gastrointestinal hormones-gastrin, secretin , cholecystokinin, and gastric inhibitory peptide3 (which seems to be the most potent)- causes a moderate increase in insulin secretion. These hormones are released in the gastrointestinal tract after a person eats a meal.Other Hormones and the Autonomic Nervous System. Other hormones that either directly increase insulin secretion or potentiate the glucose stimulus for insulin secretion include glucagon, growth hormone, cortisol, and, to a lesser extent, progesterone and estrogen3Table (Ganong 23rd/326) :Factors affecting insulin secretionStimulatorsInhibitorsGlucoseSomatostatinMannose2-DeoxyglucoseAmino acids (leucine, arginine, others)MannoheptuloseIntestinal hormones (GIP, GLP- 1 , gastrin, secretin, CCK, others?)Qa-Adrenergic stimulators (norepinephrine, epinephrine)b-Keto acidsb -Adrennergic blockers (propranolol) StimulatorsInhibitorsAcetylcholineThiazide diureticsGlucagonsGalaninCyclic AMP and various cAMP- generating substanceDiazoxideb-Adrenergic stimulatorsK+ depletionTheophylinePhenytoin; Microtubule inhibitorsSulfonyl ureasAlloxan; Insulin
Gastrin
Secretin
VIP
G1P
Pancreas