OBJECTIVETo investigate the changes in hydrogen sulfide (H2S) and cystathionine gamma-lyase (CSE) in rats with severe burn, and to analyze the effects on important organs.

METHODSOne hundred and four healthy male SD rats were divided into normal control group (NC, n = 8), burn group (B, n = 48), and H2S intervention group (HI, n = 48) according to the random number table. SD rats in HI group were intraperitoneally injected with NaHS (56 micromol/kg) once a day for 5 days. Then rats in HI and B groups were subjected to 30% TBSA full-thickness burn. Blood sample as well as heart, liver, lung, kidney, and stomach tissue samples were harvested from rats in B group at post burn hour (PBH) 2, 6, 12, 24, 48, and 96 respectively for determination of serum content of H2S and CSE activity. Serum content of alanine transaminase (ALT), aspartate aminotransferase (AST), MB isoenzyme of creatine kinase (CK-MB), urea nitrogen (BUN), and creatinine (Cr) in HI and B groups were examined at each time point. Samples were harvested from above organs in each group for histomorphological observation. Above-mentioned indexes were also determined in NC group as control. Data were processed with SNK- q test, t test, correlation analysis (between serum content of H2S and CSE activities, biochemical indexes).

RESULTSSerum content of H2S and CSE activities of above organs (except for lung tissue at PBH 48, 96) in B group within PBH 96 were lower than those in NC group, reaching minimum values at PBH 6 or 12. Compared with those in NC group, serum contents of all biochemical indexes in B group were obviously increased within PBH 48, in which serum contents of BUN [(32.5 +/- 9.8) mmol/L] and Cr [(65 +/- 9) micromol/L] reached peak at PBH 6, and serum contents of ALT [(423 +/- 59) U/L], AST [(993 +/- 60) U/L], and CK-MB [(49 261 +/- 6637) U/L] peaked at PBH 12. Serum contents of all biochemical indexes in HI group at each time point were significantly decreased as compared with those in B group, but the same change tendencies were showed in both groups. Histomorphological observation showed that all the organs were severely injured in B group at PBH 24, whereas those in HI group were markedly ameliorated. Serum content of H2S in B group was respectively correlated with CSE activities of all organs (with r value from 0.639 to 0.894, P values all below 0.005) and serum contents of biochemical indexes (with r value from 0.301 to 0.585, P values all below 0.001).

CONCLUSIONSH2S/CSE system may take part in pathophysiological process in rats with severe burn. Exogenous H2S replacement therapy can protect important organs of rats with severe burn.