Hydrogen sulphide (H2S), a naturally occurring gasotransmitter, is a potent vasodilator and pro-inflammatory mediator. DL-Propargyl glycine (PAG) is an irreversible inhibitor of the H2S synthesizing enzyme cystathionine-γ-lyase (CSE). PAG blocks H2S synthesis activity in rat liver preparations with an IC50 value of 55 μM and abolishes the rise in plasma H2S in anaesthetized rats induced with hemorrhagic shock. At concentrations ranging from 25-100 mg/kg, PAG can reduce H2S-associated inflammation in rodent models of pancreatitis, oedema, and endotoxemia.
