[Effects of stimulation and blockade of the synthesis of endogenous hydrogen sulfide at myocardial ischemia-reperfusion].

In experiments on isolated rat hearts, perfused according to Langendorff method, the effects of stimulation of the synthesis and blockade of endogenous hydrogen sulfide in myocardial ischemia-reperfusion (20 min/40 min) was studied. L-cysteine (121 mg/kg), precursor of endogenous hydrogen sulfide was injected intraperitoneally 30 minutes before the experiment without and within 10 minutes after administration of DL-propargylglycine (11.3 mg/kg) ("Sigma", USA)--inhibitor of cystathionine-gamma-lyase. The heart function was assessed by measuring the LVDP, dP/dt, coronary flow, heart rate. The opening of mitochondria permeability transition (MPT) pore was estimated by releasing of a stable factor with UV absorbance (lambda(max) 250 nm) into the coronary outflow probes during the initial phase of reperfusion. Administration L-cysteine was accompanied by a decrease of reperfusion disorders in cardiac function compared to control rats. The results showed that L-cysteine pretreated hearts against the blockade of cystathionine-gamma-lyase with DL-propargylglycine exerted a powerful cardioprotective effect in ischemia-reperfusion injury. Significant post-ischemic recover of heart function and improving the efficiency of oxygen metabolism was accompanied with tiny quantity of mitochondrial factor releasing comparing to I/R group. Positive influence of the combined DL-propargylglycine and L-cysteine action was the prevention of MPT pore opening.