Human Endocrine Physiology May 8, 2014

Lungs

Actions of AII and Aldosterone Angiotensin II Stimulates aldosterone secretion Causes vasoconstriction Stimulates thirst Aldosterone

Vasopressin

Stimulation of Vasopressin (ADH) Secretion Stimulated by: ↓ Blood volume or pressure ↓ Plasma osmolarity (low serum sodium concentration; detected by osmoreceptors in the hypothalamus)

Actions of Vasopressin/ADH ↑ permeability of the distal collecting duct to water (ADH) ↑ Free water absorption ↑ Blood volume ↓ Serum sodium concentration Vasoconstriction (vasopressin)

Combined Effects Combined Effects

Endocrine Response to Hemorrhage

ACE Inhibitors for Treatment of Hypertension How do they work? What could be potential side effects?

Erythropoetin

Erythropoetin Function: Stimulates erythrocyte production ↑ the O2 carrying capacity of the blood Secretion sites Kidney (major) Liver (minor) Secretion ↑ ’d when O2 delivery to the kidney is ↓ ’d

Erythropoetin Function: Stimulates erythrocyte production ↑ the O2 carrying capacity of the blood Secretion sites Kidney (major) Liver (minor) Secretion ↑ ’d when O2 delivery to the kidney is ↓ ’d

Hemorrhage and Erythropoetin

IGF-1 Lipid Metabolism

Roles of Lipoproteins Carry triglycerides and cholesterol to tissues Chylomicrons, VLDL, IDL, LDL in order of decreasing content of TG’s Associated with apoprotein B Carry cholesterol away from tissues HDL Associated with apoprotein A

Functions of Apoproteins Activate enzymes such lipoprotein lipase (LPL) that process the lipids Bind to cell receptors to stimulate intake of lipoproteins

Lipases Pancreatic lipase Secretion stimulated by CCK Active in the small intestine in a basic environment provided by bicarb secreted under the influence of secretin Lipoprotein lipase (LPL) On the walls of capillaries Stimulated by insulin Hormone sensitive lipase Within adipocytes Stimulated by epinephrine

Functions of Insulin Promotes glucose uptakes by cells Promotes utilization of glucose for energy Suppresses generation of ketones Amino acid uptake by cells and protein synthesis Glycerol and fatty acid uptake by adipose tissue and triglyceride synthesis Suppresses ketone formation, lipolysis, etc

* *Hormone sensitive lipase: Stimulated by epinephrine and inhibited by insulin.

LDL Receptors

IGF-1 Lipoprotein metabolism Lipid Metabolism

Examples of Hormones and Behavior

Stress Hormones: Behavioral Acquisition and Retention ACTH Fragments promote learning and memory Vasopressin Promotes learning and memory Endorphins Diminish pain Involved in learning

Experiments: 1)Inject oxytocin into ventricles of nonpregnant rats 2)Treat with an oxytocin antagonist

Politics and Endocrinology: The Birth Control Pill

Hormones and Glucose and Lipid Metabolism

Type 1 Diabetes

Summary of Problems with Untreated Type 1 Diabetes Elevated blood glucose Excess ketones leading to acidosis Inability to process glucose and loss through the kidneys leads to ↓ weight. Loss of water with glucose through the kidney leads to dehydration Mental dysfunction/coma