An inhibitor of phosphodiesterase activity would have which of the following effects?
A) block the response of epinephrine
B) decrease the amount of cAMP in the cytoplasm
C) block the activation of G proteins in response to epinephrine binding to its receptor
D) prolong the effect of epinephrine by maintaining elevated cAMP levels in the cytoplasm
E) block the activation of protein kinase A

Question

Quizplus · Accepted Answer

Inhibiting phosphodiesterase activity would prevent the breakdown of cAMP, leading to elevated levels of cAMP in the cytoplasm. Epinephrine activates adenylate cyclase, which in turn increases cAMP levels. Prolonging the effect of epinephrine by maintaining elevated cAMP levels in the cytoplasm would therefore be the effect of an inhibitor of phosphodiesterase activity.

An Inhibitor of Phosphodiesterase Activity Would Have Which of the Following