63) .GLUCAGON

[Editor]

a) stimulates insulin release
b) is secreted in increasing concentrations during starvation
c) stimulates gluconeogenesis
d) stimulates glycogenolysis
e) is secreted by the islets of langerhans

[Editor]

TTTTT

Glucagon is a polypeptide consisting of 29 amino acids. It is synthesized and released by the A cells of the Islets of Langerhans in the pancreas (B cells synthesize insulin, D cells secrete somatostatin). The actions of glucagon (via cAMP) mainly antagonize those of insulin.
-promotes hepatic glycogenolysis, gluconeogenesis,
-promotes lipolysis
-increases insulin, growth hormone, somatostatin secretion
-increases ketogenesis
-also direct positive inotropic effect on heart
Secretion is increased by beta-adrenergic stimulation, stress, exercise, amino acids, gastrin, and starvation.

[jijindr]

can you help me to understand how glucagon increases insulin release if it antagonises insulin action