Renin-Angiotension

Question 1

Where is Renin released from?

Answer 1

Juxtaglomerular apparatus

Question 2

How is Renin release regulated?

Answer 2

1. Intrarenal Baroreceptor, if low blood volume/pressure
2. Macula Densa, if low Na+/Cl- in blood
3. B1 Adrenergic Stimulation

Question 3

What would be the symptoms related to elevated ANGII hypertension?

Answer 3

Increased vasoconstriction and increased Aldosterone, thus Na+/water retention and increased BP. Cell growth and heart remodeling. Increases Afterload and aldosterone increases preload.

Question 4

Effects of ANGII on AT1?

Answer 4

Vasoconstriction
Increases sympathetic tone - extra NE release (binding A1, further vasoconstriction)
Causes release of Aldosterone from adrenal gland
Cardiac myocyte proliferation/heart hypertrophy

Question 5

What are the effects of AT2 receptor?

Answer 5

Vasodilation, Antiproliferation, Apoptosis

Question 6

What is the AT1 inhibitor and what does it do?

Answer 6

Losartan. Decreases Aldosterone, decreases sympathetic tone, vasodilation, which all allow for reduced blood pressure.

Question 7

What are special effects of Losartan?

Answer 7

ANGII is still being produced by renin, but AT1 receptors are blocked, so they are binding to AT2 causing further vasodilation. Losartan also requires several weeks to take full effect. Improves survivability of CHF

Question 8

What are the three most common ACE inhibitors and what do they do?

Answer 8

Captopril, Enalapril, and Lisinopril.
Inhibits ACE preventing conversion of AngI to AngII and also prevents the breakdown of bradykinin.
Causing vasodilation and lower blood pressure without effecting the heart.

Question 9

What are adverse side effects of ACE inhibitors?

Answer 9

1. Cough
2. Rash
3. Angioedema (due to bradykinin)
4. Taste differences

Question 10

What are the radical differences between responsiveness to ACE Inhibitors?

Answer 10

Asian/White respond the most to ACE inhibitors and African Americans are the least

Question 11

What drug can inhibit renin from converting AngI to AngII?

Answer 11

Aliskiren, binds in the active site preventing activity of the Renin.

Question 12

What drugs can inhibit release of renin from kidney cells by decreasing adrenergic stimulation?

Answer 12

Metoprolol and Propranolol. B1 antagonist inhibit release of Renin.

Question 13

What are the two Aldosterone antagonists?

Answer 13

Spironolactone and Eplerenone, inhibit Na+ retention, increases survival with CHF