비아그라에 대한 새로운 단계별 지도

Sexual stimulation that contributes to an erection brings about the output and release of nitric oxide inside the penis. Nitric oxide brings about an enzyme, guanylate cyclase, to create cyclic guanosine monophosphate (cGMP) that may be mainly answerable for rising and reducing the dimensions of blood vessels carrying blood to and with the penis an