??? ???? ????? ?? ??? ??? ?? ??? ?? ? ?? ?? ??? ?????.????? ?? ?? ??? ???? ? ????? ???? ?? ???, ?? ?? ??? ????.?? ? ??? ?? ?? ???? ?? ????. ???? ?? ? ????? ?? ??? ????.?? ????? ?????? ?? ???? ?? ?? ????? ????? ?? ?????. ?? ??? ??? ???? ?????.????? ?? ?????? ??? ?? ??? ??? ? ????. ??? ???? ?? ??? ???? ???.???? ?? ?? ? ??? ?? ??? ??? ? ????, ?? ??? ?

Sildenafil is often a potent and selective inhibitor of cGMP-precise phosphodiesterase kind 5 (PDE5), which happens to be liable for degradation of cGMP during the corpus cavernosum. The molecular structure of sildenafil is comparable to that of cGMP and functions to be a aggressive binding agent of PDE5 within the corpus cavernosum, causing additi