HHP 3500 Lecture 47: Neural Control of Metabolism
Document Summary
Lecture 47: endocrine and neural control of metabolism. Control of energy through 2 main hormones: insulin. Storage hormone secreted by b-cells from islets of langerhans. Increases during absorptive state, decreases during post- absorptive state. Muscle: in skeletal muscle, insulin increases glucose and amino acid uptake from blood, increases synthesis of glycogen and intracellular proteins. Adipose: increases glucose uptake, increase triglyceride synthesis (stored fat) Liver/hepatocytes: insulin does not effect uptake, but increases net synthesis of glycogen and triglycerides in liver. Insulin in peptide hormone (hydrophilic)-soluble in plasma; receptor is located on outer cell membrane ; results in second messenger cascade to amplify response. Insulin"s cascade triggers translocation of glut 4 transporters, inserting transporters into membrane of muscle and fat cells; this increases glucose uptake. Receptors: beta cells in islet cells of pancreas are sensors. Effectors are skeletal muscles, fat tissue, and liver. Increase in plasma amino acid levels (from increased protein consumption stimulates insulin release: 2.