OBJECTIVETo assess the protective effect of exogenous hydrogen sulfide (H₂S) against myocardial injury after skeletal muscle ischemia/reperfusion (IR) in rats and explore the mechanism.

METHODSThirty-one Wistar rats were randomized into normal control (n=8), IR group (n=8, with a 4-h reperfusion following a 4-h ischemia of the bilateral hindlimbs induced using a tourniquet), NaHS group (n=8, with IR and intraperitoneal injection of 14 µmol/kg NaHS), and DL-propargylglycine (PPG) group (n=7, with IR and intraperitoneal injection of 50 mg/kg PPG). The plasma levels of CK-MB and the levels of MPO, TNF-α, MDA, T-SOD, and CuZn-SOD in the plasma and myocardial tissues were measured. The expression of TNF-α in the myocardium was examined using immunohistochemistry. RESULTS Skeletal muscle IR induced significantly increased plasma CK-MB level (P<0.05) and the levels of MPO, TNF-α, and MDA in the plasma and myocardium, and significantly decreased plasma and myocardial levels of T-SOD and CuZn-SOD (P<0.05). NaHS treatment significantly decreased plasma CK-MB level (P<0.05), reduced plasma and myocardial levels of MPO, TNF-α, and MDA, and increased plasma and myocardial T-SOD and CuZn-SOD in rats with IR (P<0.05), whereas PPG treatment did not produce any obvious responses (P>0.05). Immunohistochemistry showed an obviously reduced expression of TNF-α in the myocardium in rats with NaHS treatment compared with those in IR group.

CONCLUSIONH₂S treatment can alleviate myocardial injury induced by skeletal muscle IR in rats by inhibiting the inflammatory cytokines and oxidative stress.