Vasodilators

Question 1

Why does increasing K channels relax vascular smooth muscle?

Answer 1

K flux sets the membrane potential

-Longer the K channels are open, the closer the membrane potential is to K equilibrium potential

-The harder it is to depolarize the membrane enough to open calcium channels

Question 2

What are the K Channel Agonists?

Answer 2

Minoxidil

Diazoxide

Adenosine

Question 3

What activates minoxidil?

Answer 3

Sulfotransferase 1A1

Question 4

What is minoxidil given with?

Answer 4

Loop diuretics

Beta blockers

Question 5

How is diazoxide administered and what does it treat?

Answer 5

Administered IV for acute hypertension

Question 6

Besides vasodilation, what other effect does diazoxide have?

Answer 6

Inhibits insulin release from pancreatic beta cells

Used orally for patients with genetic hyperinsulinemia

Question 7

What does adenosine bind to?

Answer 7

A1 receptor through a GPCR

Question 8

What is the effect of adenosine?

Answer 8

Increases conductance of K channel

(Done through G (beta gamma) binding and activating GIRK which conducts K efflux and membrane hyperpolarization)

Question 9

Which isoform of NO is in vascular endothelium?

Answer 9

eNOS

Question 10

What is the effect of NO?

Answer 10

Produces relaxation in the vascular smooth muscle