How does Viagra enhance erectile function of the penis?
A)by inhibiting nitric oxide release
B)by inhibiting guanylyl cyclase activity
C)by preventing cGMP production
D)by inhibiting cGMP phosphodiesterase
E)by inhibiting cGMP phosphatase

Question

Quizplus · Accepted Answer

Viagra (sildenafil) works by inhibiting the enzyme phosphodiesterase type 5 (PDE-5), which is responsible for breaking down cyclic guanosine monophosphate (cGMP). By inhibiting PDE-5, Viagra increases the levels of cGMP in the smooth muscle of the penis, leading to relaxation and increased blood flow, which results in improved erectile function. Option A, B, and C are incorrect because they inhibit the production and release of cGMP, which is the opposite of what Viagra does. Option E is also incorrect as it is not involved in the pathway of Viagra's mechanism of action.

How Does Viagra Enhance Erectile Function of the Penis