비아그라에 대한 새로운 단계별 지도

Sexual stimulation that leads to an erection causes the manufacturing and launch of nitric oxide while in the penis. Nitric oxide brings about an enzyme, guanylate cyclase, to provide cyclic guanosine monophosphate (cGMP) that is generally accountable for rising and reducing the scale of blood vessels carrying blood to and from the penis and trigge

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