오늘 사용할 수 있는 비아그라에 대한 5가지 팁

Sexual stimulation that leads to an erection triggers the creation and launch of nitric oxide during the penis. Nitric oxide leads to an enzyme, guanylate cyclase, to generate cyclic guanosine monophosphate (cGMP) that is mainly responsible for rising and reducing the size of blood vessels carrying blood to and with the penis and producing an erect