비아그라에 대해 거의 알려지지 않은 사실

Sexual stimulation that results in an erection leads to the creation and release of nitric oxide inside the penis. Nitric oxide leads to an enzyme, guanylate cyclase, to produce cyclic guanosine monophosphate (cGMP) that's primarily responsible for expanding and lowering the dimensions of blood vessels carrying blood to and from the penis and causi