Renin, Angiotensin, And Vascular Tone

Question 1

Nitric oxide

Answer 1

Contraction results from phosphorylation of MLC by MLCK, activated by Ca
Relaxation follows when phosphorylated light chains are dephosphorylated (facilitated by cGMP)

Question 2

Nitroglycerin and Isosorbide mononitrate

Answer 2

Requires breaks for tolerance
Dependence, withdrawal
Ha, reflex tachycardia, postural hypotension
CI: pts on PDE5 inhibitors

Question 3

Sodium nitroprusside

Answer 3

Arterial and venous dilation from NO release

Monitor cyanide and metHb

Question 4

PDE5 inhibitor

Answer 4

Do not inc NO but potentiate the NO effect
-afil
Synergistic hypotension with nitroglycerin and PDE5 inhibitors

Question 5

K channel openers

Answer 5

Hydralazine and Minoxidil

Enhance K efflux and dec Ca entry

Question 6

Alpha 1 Antagonists

Answer 6

Anti-HTN: Prazosin, Terazosin, Doxazosin
BPH: Alfuzosin and Bunazosin, Tamsulosin and Silodosin
Vasodilation

Question 7

B1 Blockers

Answer 7

-olols
Dec HR
Prolong SA node recovery, slows conduction to AV node
Dec myocardial contractility -> myocardial O2 demand
Dobutamine -> dilation -> dec after load and inc CO

Question 8

Alpha and beta Antagonists

Answer 8

Labetalol and Carvedilol

Question 9

Fenoldepam

Answer 9

Dilation of renal arteries may offer advantage when kidneys are suffering from severe HTN