Renal Hormones

Question 1

PTH

Answer 1

• released when serum Ca2+ decreases
• basolateral receptor
• activates adenylate cyclase increases cAMP in urine
• Decreases phosphate reabsorption in proximal tubule
• increases Ca2+ reabsorption in distal tubule
• stimulates 1alpha hydroxylase in proximal tubule

Question 2

ADH

Answer 2

• secreted in response to low blood volume or high plasma osmolarity
• binds basolateral V2 receptor
• AC activated and increases cAMP
• inserts AQP2 H2O channels into apical membrane

Question 3

Aldosterone

Answer 3

• stimulated by decreased blood volume via RAAS
• stimulated by increased plasma K+
• slow action via new protein synthesis
• increases Na+ reabsorption in distal tubule principal cells
• increases K+ secretion in distal tubule principal cells
• increases H+ secretion by distal tubule alpha intercalated cells

Question 4

ANP

Answer 4

• stimulated by increased atrial pressure
• guanylate cyclase stimulated cGMP
• increases GFR
• decreases Na+ reabsorption

Question 5

Angiotensin II

Answer 5

• stimulated by decreased blood volume via renin
• increases Na+/H+ exchange
• increases HCO3- reabsorption