비아그라에 대한 사실 아무도 제안하지 않는다
Sexual stimulation that causes an erection leads to the generation and release of nitric oxide in the penis. Nitric oxide leads to an enzyme, guanylate cyclase, to provide cyclic guanosine monophosphate (cGMP) that is certainly principally accountable for raising and decreasing the dimensions of blood vessels carrying blood to and from your penis a