Discovery of NO in the penis

In 1989, the recognition by our group at UCLA that nitric oxide was indeed the chemical mediator of penile erection turned out to have major influences on our society and on some of those who participated in this research. Not only did it ultimately lead to the development of drugs like sildenafil, vardenafil and tadalafil, it launched new businesses, it gave insight into the way the vascular system functioned, it changed the way many physicians, particularly urologists, practiced sexual medicine and by bringing the topic of erectile dysfunction out of the closet, talk of sexual issues became mainstream. For one of us, a Nobel Prize lay in the future. This review, which comes one decade following the introduction of Viagra into the marketplace, chronicles the actual events involved in the discovery.