Question

what is meant by insulin and glucagon antagonists and how are they useful in normal body function ?

Answer 1

INSULIN AND GLUCAGON

Insulin and glucagon are hormones secreted by the pancreas which play a role in the regulation of blood glucose by their antagonistic effects on glucose metabolism. These two hormones acts to maintain the blood sugar level within the normal range.

Insulin is secreted by the beta cells of the pancreas. Insulin is secreted when the blood glucose level is high.  Insulin is an anabolic hormone and acts via different metabolic pathways to decrease the concentration of glucose and fatty acids in the bloodstream. Insulin favours glucose uptake by the cells from the blood stream thus lowering blood glucose. It favours glygogenesis i.e conversionn of glucose to glycogen in the liver and inhibits Gluconeogenesis i.e, synthesis of glucose from other substances.

Glucagon is produced by alpha cells of the pancreas. Glucagon is secreted when the blood glucose level is low. Glucagon is a catabolic hormone and via different metabolic pathways to raise the concentration of glucose and fatty acids in the bloodstream. Glucagon instructs the liver to release stored glucose by conversion of stored glycogen to glucose - a process is called glycogenolysis. It promotes gluconeogenesis i.e, synthesis of glucose from other substances and fatty acid synthesis.