Author(s): Leta Melaku and Andualem Mossie
In addition to nitric oxide and carbon monoxide, hydrogen sulfide (H2S) is the third gasotransmitter in mammals. It is synthesized from L-cysteine by cystathionine β-synthase, cystathionine γ-lyase or by sequential action of alanine aminotransferase and 3-mercaptopyruvate sulfur transferase. Although initially it was suggested that in the vascular wall H2S is synthesized only by smooth muscle cells and relaxes them by activating ATP-sensitive potassium channels, more recent studies indicate that H2S is synthesized in endothelial cells as well. The physiological functions of H2S are mediated by different molecular targets, such as different ion channels and signaling proteins. Endogenous H2S is involved in the regulation of many physiological processes in the cardiovascular system including the regulation of vascular tone, blood pressure and inhibits atherogenesis. Many new technologies have been developed to detect endogenous H2S production, and novel H2S-delivery compounds have been invented to aid therapeutic intervention of diseases related to abnormal H2S metabolism. The primary purpose of this review was to provide an overview of the role of H2S in the blood vessel, methods of endogenous production detections and common ion channels used to produce its biological effect describe its beneficial effects.
