Muscle relaxation in response to nitric oxide would be reduced if a(n)__________ was present.
A) stimulator of cGMP phosphodiesterase
B) inhibitor of protein kinase A
C) inhibitor of acetylcholine esterase
D) stimulator of guanylate cyclase

Question

Quizplus · Accepted Answer

Nitric oxide activates guanylate cyclase, which in turn converts GTP into cGMP. cGMP activates protein kinase G, which promotes muscle relaxation. However, cGMP can also be broken down by cGMP phosphodiesterase. A stimulator of cGMP phosphodiesterase would reduce cGMP levels and therefore reduce muscle relaxation in response to nitric oxide.

Muscle Relaxation in Response to Nitric Oxide Would Be Reduced