Hydrogen sulfide: metabolism, biological and medical role.

Hydrogen sulfide (H2S) is a signaling molecule that is actively synthesized in the tissues and is involved in the regulation of vascular tone, neuromodulation, cytoprotection, inflammation and apoptosis. In recent years, new data on animal and human H2S metabolism and function under the effect of various endogenous and exogenous factors, including drugs were collected. This review is provided to introduce generalized information about the main and alternative H2S metabolism and regulation, peculiarities of transport, signaling, biological role and participation in pathogenesis. Submitted data describe H2S content and activity of H2S-synthesizing enzymes in different organs, H2S effect on blood coagulation and platelet aggregation based on our research results. The working classification of H2S metabolism modulators, which are used in biology and medicine, is proposed: 1) agents that increase H2S content in tissues (inorganic and organic H2S donors; H2S-synthesizing enzymes substrates and their derivatives, H2S-releasing drugs; agents that contain H2S-synthesizing enzymes cofactors and activators, agents that inhibit H2S utilization); 2) agents that reduce H2S content in tissues (specific and nonspecific inhibitors of H2S-synthesizing enzymes), 3) agents with uncertain impact on H2S metabolism (some medicines). It was demonstrated that vitamin-microelement and microelement complexes with H2S-synthesizing enzymes cofactors and activators represent a promising approach for H2S content correction in tissues.