비아그라에 대해 거의 알려지지 않은 사실

Sexual stimulation that brings about an erection results in the output and release of nitric oxide within the penis. Nitric oxide triggers an enzyme, guanylate cyclase, to make cyclic guanosine monophosphate (cGMP) that is primarily answerable for expanding and lowering the scale of blood vessels carrying blood to and within the penis and producing