Gas what: NO is not the only answer to sexual function

The ability to get and keep an erection is important to men for several reasons and the inability is called as erectile dysfunction (ED). ED started to be accepted as an early indicator for systemic endothelial dysfunction and subsequent of cardiovascular diseases. The role of nitric oxide (NO) in endothelial relaxation and erectile function is well accepted. The discovery of NO as small signaling gasotransmitter led to the investigation of the role of other endogenously derived gases, carbon monoxide (CO) and hydrogen sulfide (H2 S) in physiological and pathophysiological conditions. The role of NO and CO in sexual function and dysfunction has been investigated more extensively and recently the involvement of H2 S in erectile function has also been confirmed. In this review, we focused on the role of these 3 sister gasotransmitters in the physiology, pharmacology and pathophysiology of sexual function in man, specifically erectile function. We also reviewed the role of soluble guanylyl cyclase /cyclic GMP pathway as a common target of these gasotransmitters. Several studies proposed alternative therapies targeting different mechanisms in addition to phosphodiesterase-5 inhibition for ED treatment, since some patients do not respond to these drugs. This review highlights complementary and possible coordinated roles for these mediators and treatments targeting these gasotransmitters in erectile function/ED.