Vasodilators I

Question 1

Vasodilators

cyclic ___ modulators
- organic nitrates
- ___ inhibitors
- natriuretic peptides

___ channel agonists

___ receptor antagonists

___ analogs - IP receptor agonists

Answer 1

• GMP
• PDE
• K
• endothelin
• PGI2

Question 2

K channel agonists/openers

why does increasing K channel open relax vascular smooth muscle?
- K flux sets membrane potential
- the longer k channels are open, the closer the membrane is to the K equilibrium potential
- the closer the membrane potential is to the K equilibrium potential, the ___ it is to depolarize the membrane enough to open ____

Answer 2

• harder
• voltage gated Ca2+ channels

Question 3

Vasodilators - K + channel Agonists/openers

minoxidil
- activated in vivo by sulfotransferase 1A1
- used with ___ diuretics and ___ blockers
- very ___ vasodilator - effective in severe, drug resistant forms of hypertension
- cAMP PDE inhibition may contribute to its efficacy
- given PO (topically for hair growth)

Answer 3

• Loop, beta
• potent

Question 4

K + channel agonists/openers

diazoxide
- used ___ to treat acute HTN
- very __ vasodilator - effective in severe drug resistant forms of HTN
- inhibits release of ___ from ___ cells
- used PO for ___

Answer 4

• IV
• potent
• insulin, pancreatic B cells
• hypoglycemia

Question 5

adenosine
- binds to A1 receptor - ___
- increases conductance of ___ channel; hyperpolarization, relaxation
- given IV - coronary ___ test
- also supraventricular ___

Answer 5

• a GPCR
• K+
• stress
• arrhythmias

Question 6

hyperpolarization of vascular smooth muscle by adenosine

GIRK

Answer 6

G-protein activated inwardly rectifying K channel

Question 7

Nitric oxide cyclic GMP pathway

eNOS
endothelium nitric oxide synthase - found in ___
break down ___ into ___
to make NO

Answer 7

vasculature
L-arginine, L-citruline

Question 8

ACh relaxes smooth muscle via NO
- endothelium is important bc of

Answer 8

eNOS