Cv System - Vasopressin

Front 1

Name 3 reasons for stimulation of vasopressin

Back 1

1. increase in osmolality
2. severe hypovolemia
3. severe hypotension

*go through posterior pituitary to release ADH

Front 2

V1 and V2 vasopressin receptors location and function

Back 2

V1- on vascular smooth muscle--> vasoconstriction

V2- Renal collecting duct, vascular endothelium
->regulate how much water is in the body
-> release clotting factor VIII and vWF from storage sites

Front 3

Why doesn't vasopressin increase blood pressure?

Back 3

affinity for the V2 receptor is much higher than for V1, so you need a much higher concentration to activate the V1 receptors

Front 4

MoA of vasopressin

Back 4

ADH binds to the V2 receptor on the basolateral membrane of the principal cells of collecting ducts, which activates Gs then adenylyl cyclase to increase cAMP concentrations, which activates PKA to induce water channels to travel to the cell's apical membrane.

Front 5

difference between vasopressin and desmopressin?

Back 5

desmopressin is a D-arginine which increases the half-life, and is more selective for V2 receptor. Desmopressin affects urine output more.

Front 6

Central Diabetes Insipidus

Back 6

vasopressin not released from stimulated post. pituitary. Use desmopressin to tx b/c there will be less side effects.

Front 7

Nephrogenic Diabetes Insipidus

Back 7

insufficient response when vasopressin binds to V2 receptors (in renal collecting duct). problem in the kidney itself. Tx is adequate fluid intake and thiazide diuretic. Desmopressin isnt a good tx b/c body is already making enough. Just the receptor is messed up.

Front 8

clinical use of vasopressin

Back 8

advanced cardiac life support, vasodilatory shock

Front 9

use for desmopressin?

Back 9

primary noctural enuresis (bed wettting), which will reabsorb h20, decrease urine volume by binding to the v2 receptors in the kidney.

hemophilia A or Type 1 von Willebrand's disease.

Front 10

Adverse reactions for vasopressin?

Back 10

hypertension, coronary vasospasm and ischemia

Front 11

Vasopressin/Desmopressin adverse rxns

Back 11

water intoxication, hyponatremia

Front 12

Desmopressin adverse reactions

Back 12

congestion, rhinitis (for intranasal desmopressin)

Front 13

what do you use for central diabetes insipidus?

Back 13

since there is an inadequate amount of vasopressin released from the pituitary, you treat with desmopressin, though the v1 receptors on the vascular smooth muscles are unaffected.