Hormones that affect energy metabolism © Michael Palmer 2014.
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Transcript of Hormones that affect energy metabolism © Michael Palmer 2014.
Hormones that affect energy metabolism
© Michael Palmer 2014
Langerhans’ islets in the pancreas produce insulin and glucagon
© Michael Palmer 2014
A little bit of history: The purification of insulin—the problem
© Michael Palmer 2014
The purification of insulin—Banting’s solution
© Michael Palmer 2014
Historical side note: Norman Bethune, Banting’s famous classmate
© Michael Palmer 2014
Structure of insulin and its precursors (1)
© Michael Palmer 2014
Structure of insulin and its precursors (2)
© Michael Palmer 2014
Sequences of human, swine, and bovine insulins
© Michael Palmer 2014
Insulin secretion in the β-cell is controlled by glucose and triggered by membrane depolarization
© Michael Palmer 2014
The sulfonylurea receptor controls an associated potassium channel
© Michael Palmer 2014
KATP
channels also regulate the tone of smooth muscle cells
© Michael Palmer 2014
Tolbutamide promotes closing of the KATP
channel
© Michael Palmer 2014
The insulin receptor is a receptor tyrosine kinase
© Michael Palmer 2014
Insulin receptor first phosphorylates itself and then a number of insulin receptor substrate proteins
© Michael Palmer 2014
Insulin effects on glycogen synthesis
© Michael Palmer 2014
The role of insulin in glucose transport
© Michael Palmer 2014
Insulin promotes glucose uptake by increasing the surface exposure of GLUT 4 transporters
© Michael Palmer 2014
Transcriptional regulation by insulin
© Michael Palmer 2014
Other hormones
© Michael Palmer 2014
Glucagon and epinephrine act via G-protein-coupled receptors
© Michael Palmer 2014
The glucagon and epinephrine receptors activate adenylate cyclase and protein kinase A
© Michael Palmer 2014
Metabolic effects of protein kinase A
© Michael Palmer 2014
Glucocorticoids and thyroid hormones act on nuclear hormone receptors to activate transcription
© Michael Palmer 2014
DNA binding by thyroid hormone receptors
© Michael Palmer 2014
Metabolic effects of glucocorticoid hormones
● induction of enzymes for glycogen synthesis, glycogen breakdown, and gluconeogenesis
● induction of enzymes for protein breakdown, supplying substrates for gluconeogenesis
● induction of adrenergic receptors
…overall, glucocorticoids increase blood glucose
Glucocorticoid receptor agonists and antagonists
© Michael Palmer 2014
Control of food intake by leptin
© Michael Palmer 2014