Role of hydrogen sulfide in the physiology of penile erection

Abstract

Hydrogen sulfide (H2S), which is a well-known toxic gas, has recently been recognized as a biological messenger that plays an important role in physiological and pathophysiological conditions. Relatively high levels of H2S have been discovered in mammalian tissues. It is mainly synthesized by 2 enzymes, including cystathionine β-synthase and cystathionine γ-lysase, which utilize L-cysteine as substrate to produce H2S. H2S has been demonstrated to exhibit potent vasodilator activity both in vitro and in vivo by relaxing vascular smooth muscle. Recently, H2S has been discovered in penile tissue with smooth muscle relaxant effects. Furthermore, other effects of H2S could play a role in the physiology of erection. Understanding H2S in the physiology of erection might provide alternative erectile dysfunction strategies for those patients with poor or no response to type 5 phosphodiesterase inhibitors. This review intends to present the H2S pathway in penile tissue and the potential role of H2S in the physiology of erections. © American Society of Andrology.