OBJECTIVETo investigate the effects of taurine on myocardial mitochondria and their enzyme activities in rats with severe burn.

METHODSOne hundred and twenty healthy adult Wistar rats were subjected to 30% TBSA full-thickness burn. They were randomly divided into burn group (B, with intraperitoneal injection of isotonic saline), treatment group (T, with intraperitoneal injection of taurine, 200 mg/kg),with 60 rats in each group . Ten rats with sham scald were used as control (S group). The myocardial tissue samples in B and T groups were harvested at 1, 3, 6, 12, 24 and 48 postburn hours (PBH) for determination of activity respectively of succinate dehydrogenase (SDH), cytochrome oxidase (CCO), the superoxide dismutase (SOD), Ca2+ -ATPase in mitochondria, and contents of cytochrome c (Cyt c), cytochrome aa3 (Cyt aa3), malondialdehyde (MDA), and Ca2+ in mitochondria and cytoplasm . The myocardial tissue samples of controls were harvested at 1 PBH for determination of above indices.

RESULTSThe activity of CCO in B group was decreased at 1 PBH , especially at 6 ,12 PBH. The activity of SDH in B group was decreased to lowest level at 6 PBH, and its value was lower than that of S group at each time point. The activity of CCO or SDH in T group was not obviously decreased, and the activity of CCO at 3, 6, 12 PBH showed significant difference compared with B group (P < 0.05). The contents of Cyt aa3 and Cyt c in B group at 3, 6, 12, 24 PBH were obviously decreased, which were significantly lower than those in T group (P < 0.05). The activity of SOD in B group at 3, 6, 12 PBH was obviously decreased, the activity of Ca2+ -ATPase at 3, 6, 12 and 24 PBH was decreased to different extent, which was significantly lower than those in T group (P < 0.05). The MDA contents in B and T groups were higher than that in S group at 3-48 PBH ,and it was highest in B group (P < 0.05). The Ca2+ content of mitochondria in B group at 1 PBH was increased (13.7 +/- 1.5), and it was (24.8 +/- 2.6), (29.7 +/- 3.1), (16.3 +/- 1.9) and (13.5 +/- 1.7) at 3, 6, 12, 24 PBH respectively,and they were all higher than that of S group (10.7 +/- 1.6, P < 0.05). The Ca2 contents of cytoplasm in group B at 3 - 24 PBH were also higher than that in S group (P < 0.05). The Ca2+ content of mitochondria in T group at 3, 6, 12, 24 PBH was (16.8 +/- 2.8), (18.7 +/- 1.9), (10.5 +/- 1.8) and (13.3 +/- 1.7)respectively, which were lower than that in B group at every time point.

CONCLUSIONTaurine have protective effect on mitochondria and their enzyme activities in myocardium in rats with severe burn, and it may be attributable to improving the ability of eradicating oxygen free radicals and alleviating Ca2+ overload in the mitochondria.