General

Question 1

8 arginine-vasopressin

Answer 1

ADH

Question 2

ADH synthesis

Answer 2

in paraventricular and supraoptic nuclei of hypothalamus

Question 3

ADH release

Answer 3

elevation in plasma osmolarity > 280
Depletion of extreacellular volume
pain
nausea
hypoxia

Question 4

V1 receptors and their activation

Answer 4

found in vascular smooth musclevasopressin binds to V1R…activates G-PLC-IP3 pathway, mobilizes Ca2+ causing vasoconstriction

Question 5

V2 receptors and their activation

Answer 5

principal cells in renal collecting ducts

binding of vasopressin activates Gs-cAMP, PKA

PKA increases rate of insertion of H2O channel containing vesicles into apical membrane of CD

PKA phosphorylates H2O forming channel AQP-2…inserted as tetramers into apical membrane

PKA also phosphorylates the rea transporter (VRUT or UT1) and then increases permeability of CD to urea

Concentrates urine up to 4 times osmolarity of plasma!!!