비아그라에 대한 새로운 단계별 지도

PDE3 is associated answerable for cardiac contractility. Sildenafil is only about ten-fold as strong for PDE5 when compared with PDE6, an enzyme present in the retina which is linked to the phototransduction pathway on the retina. This decrease selectivity is considered the basis for abnormalities relevant to coloration vision [see Pharmacodynamics