The Science and Practice of Erection Physiology: Story of A ...

This year marks the 20 th anniversary of the regulatory agency approval and commercial release of Viagra (sildenafil citrate; Pfizer, New York, New York) for the treatment of erectile dysfunction, defined as "the consistent inability to attain and maintain a penile erection sufficient for sexual satisfaction" . The timing is momentous for ...

Molecular mechanisms of the effects of sildenafil (VIAGRA ® )

The "classical" PDE-1 family is activated by calcium-calmodulin and has a lower K m for cGMP than for cAMP. Several isoenzymes exist, and one of them may play a role in olfaction (Beavo, 1995).The PDE-1 family is widely distributed (brain, heart) and is inhibited by sildenafil with an IC 50 value between 218-280 nM, depending on tissue and/or species.

How Viagra Works - Scientific American

On supporting science journalism. If you're enjoying this article, consider supporting our award-winning journalism by subscribing.By purchasing a subscription you are helping to ensure the future ...

VIAGRA : IS IT A WONDER DRUG - National Center for Biotechnology ...

Sildenafil citrate (Viagra) has shown promising results in recently published clinical trials. Sildenafil is a potent and competitive inhibitor of cGMp specific phosphodiesterase-5, predominant isoenzyme in the human corpus cavernosum. It is effective in erectile dysfunction of diverse origin, however it requires a patent vascular system to be ...