아무도 제안하지 않는 비아그라에 대한 사실

Sexual stimulation that leads to an erection results in the manufacturing and launch of nitric oxide from the penis. Nitric oxide results in an enzyme, guanylate cyclase, to create cyclic guanosine monophosphate (cGMP) that is certainly principally responsible for growing and reducing the dimensions of blood vessels carrying blood to and with the p