Human Endocrine PhysiologyHuman Endocrine Physiology

May 8, 2014

Lungs

Actions ofActions ofAII and AldosteroneAII and Aldosterone

• Angiotensin II• Stimulates aldosterone secretion• Causes vasoconstriction• Stimulates thirst

• Aldosterone

VasopressinVasopressin

Stimulation ofStimulation ofVasopressin (ADH) SecretionVasopressin (ADH) Secretion

• Stimulated by:• ↓ Blood volume or pressure• ↓ Plasma osmolarity (low serum

sodium concentration; detected by osmoreceptors in the hypothalamus)

Actions ofActions ofVasopressin/ADHVasopressin/ADH

• ↑ permeability of the distal collecting duct to water (ADH)• ↑Free water absorption• ↑Blood volume• ↓Serum sodium concentration

• Vasoconstriction (vasopressin)

Combined EffectsCombined Effects

Endocrine Response to Endocrine Response to HemorrhageHemorrhage

ACE Inhibitors for Treatment ACE Inhibitors for Treatment of Hypertensionof Hypertension

• How do they work?

• What could be potential side effects?

ErythropoetinErythropoetin

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 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 Hemorrhage and Erythropoetin Erythropoetin

IGF-1

Lipid MetabolismLipid Metabolism

Roles of LipoproteinsRoles 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 ApoproteinsFunctions of Apoproteins

• Activate enzymes such lipoprotein lipase (LPL) that process the lipids

• Bind to cell receptors to stimulate intake of lipoproteins

LipasesLipases• 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 InsulinFunctions 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 MetabolismLipid Metabolism

Examples of Examples of Hormones and BehaviorHormones and Behavior

Stress Hormones: Behavioral Stress Hormones: Behavioral Acquisition and RetentionAcquisition 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 rats2) Treat with an oxytocin antagonist

Politics and Endocrinology:Politics and Endocrinology:The Birth Control PillThe Birth Control Pill

Hormones and Hormones and Glucose and Lipid Glucose and Lipid

MetabolismMetabolism

Type 1 DiabetesType 1 Diabetes

Summary of Problems with Summary of Problems with Untreated Type 1 DiabetesUntreated 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