비아그라에 대해 거의 알려지지 않은 사실

Sexual stimulation that causes an erection triggers the creation and launch of nitric oxide within the penis. Nitric oxide triggers an enzyme, guanylate cyclase, to produce cyclic guanosine monophosphate (cGMP) that is mostly responsible for growing and reducing the scale of blood vessels carrying blood to and from your penis and triggering an erec