THE SCIENCE AND PRACTICE OF ERECTION PHYSIOLOGY: STORY OF A REVOLUTIONARY GASEOUS MOLECULE.

The field of sexual medicine, in reference to the science of the sexual response and the clinical management of sexual dysfunctions, has evolved remarkably in the last 25 years. Erection biology has been central in driving this progress and is measured considerably by the discovery, study, and clinical translation of a simple gaseous molecule, nitric oxide, which is operative in the penis. Nitric oxide functions extraordinarily as a neurotransmitter and molecular signal transducer. It is now well understood to be the principal molecular mediator of penile erection and to be a critical element involved in dysregulatory mechanisms of erection disorders ranging from erectile dysfunction to priapism. It is most familiarly associated with the scientific development of oral medications for treating erectile dysfunction, which has modernized the clinical management of this condition.