Hydrogen sulfide: A new EDRF

Abstract

The first endothelium-derived relaxing factor (EDRF) ever identified is a gasotransmitter, nitric oxide (NO). Recent studies have provided several lines of evidence to support the premise that hydrogen sulfide (H 2 S), another gasotransmitter, is a new EDRF. H 2 S production is catalyzed in mammalian cells by cystathionine Β-synthase (CBS) and/or cystathionine γ-lyase (CSE). The expression of CSE proteins and the activity of CBS have been observed in vascular endothelial cells. A measurable amount of H 2 S is produced from endothelium upon muscarinic cholinergic stimulation. The endothelium-dependent vasorelaxation induced by H 2 S shares many common mechanistic traits with those of endothelium-derived hyperpolarizing factor (EDHF). Deficiency in CSE expression increases blood pressure in CSE knockout mice and significantly diminishes endothelium-dependent relaxation of resistance arteries. More extensive and mechanistic studies in the future will help to determine whether H 2 S is a new EDRF or the very EDHF. © 2009 Inernational Society of Nephrology.