When E2Fs are bound to Rb, not only are they transcriptionally inactive, but they also function to repress transcription by recruiting chromatin-modifying enzymes that promote deacetylation and methylation of specific histone lysines.

TLS Online TPP Program

#Id: 6564

#Unit 7. System Physiology – Animal

The binding of glucagon to its receptor, leading to activation of protein kinase A, which inhibits glycogen synthesis and promotes glycogenolysis

TLS Online TPP Program

#Id: 6565

#Unit 7. System Physiology – Animal

TLS Online TPP Program

#Id: 6566

#Unit 7. System Physiology – Animal

Glucagon receptors located on the same hepatic cells to activate phospholipase C, and the resulting increase in cytoplasmic Ca2+ also stimulates glycogenolysis

TLS Online TPP Program

#Id: 6567

#Unit 7. System Physiology – Animal

Pancreatic B cells contain GABA, and coincident with the increased insulin secretion produced by hyperglycemia, GABA is released and acts on the A cells by activating GABA A receptors

TLS Online TPP Program

#Id: 6568

#Unit 7. System Physiology – Animal

GABA A receptors are Cl– channels, and the resulting Cl– influx hyperpolarizes the A cells to inhibit glucagon secretion 

TLS Online TPP Program

#Id: 6569

#Unit 7. System Physiology – Animal

Glucagon secretion is increased by stimulation of the sympathetic nerves to the pancreas, & sympathetic effect is mediated via β-adrenergic receptors and cAMP