Fig. 5.

Pathways of H₂S generation and mechanisms of action of polysulfide diallyl trisulfate (DATS) in mammalian cells. (1) H₂S production via glutathione-dependent conversion mechanisms. This group of processes can involve several different mechanisms, including a carbon nucleophilic attack as well as various thiol-disulfide exchange reactions (not shown); (2) H₂S production via reactions with protein-SH groups; (3) H₂S production via upregulation of CSE and/or via stimulation of CSE activity. In these processes, H₂S is produced from the endogenous substrates of CSE, l-cysteine/l-homocysteine, and DATS stimulates this reaction; (4) H₂S production via the oxidoreductase function of catalase. An additional, indirect mechanism (5) involves redox mechanisms. DATS elevates the cell’s antioxidant pools, and this attenuates the oxidative degradation of H₂S, in effect elevating the biologically available pools of H₂S.