[Protective effects of taurine on myocardial injury in severely burned rats].

Objective: To investigate the effect of taurine on myocardial injury in severely scalded rats.
Methods: A total of 130 healthy adult Wistar rats were randomly divided into 3 groups: the control group (C, without burns), the burn group (B, subjected to a 30% TBSA III degree scalding) and the treatment group (T, treated with intraperitoneal injection of taurine (400 mg/kg) immediately after scald injury). The plasma and myocardial tissue samples in B and T groups were harvested at 1, 3, 6, 12, 24 and 48 postburn hours (PBH) for the determination of the contents of cardiac troponin T (cTnT), malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-alpha), and angiotensin II (AngII) in plasma, and the contents of TNF-alpha, AngII and calcium ion in myocardial tissue. The morphological change in the myocardial tissue was observed with transmission electronic microscope (TEM) and was compared with that in C group. The changes in the plasma TNF-alpha and AngII were analyzed in relation to that of plasma cTnT.
Results: The plasma cTnT content in B group at 3 PBH was markedly higher than that in C group (0.16 +/- 0.03 microg/L) (P < 0.01), and it peaked (6.32 +/- 0.41) at 12 PBH and remained at high level at 48 PBH. While the plasma MDA content and the calcium ion level in B group were evidently higher than those in C group during 3 to 48 PBH (P < 0.01). The TNF-alpha contents in plasma and myocardial tissue during 6 to 48 PBH were significantly higher than those in C group (P < 0.01). The AngII contents in plasma and myocardial tissue during 3 to 24 PBH were obviously higher than those in C group (P < 0.01). All the indices in T group were significantly lower than those in B group (P < 0.01). Histological examination revealed that there was myocardial damage in various degrees during early postburn stage in B group, such as focal dissolution and fragmentation of myofilament, mitochondrial edema, myocyte sarcoplasmic protrusions like piano keys. But all the above changes in T group were evidently ameliorated to near normal. There was close positive correlation between the change in the concentrations of plasma content of TNF-alpha and AngII and cTnT in B group (r = 0.87 and 0.82, P < 0.05).
Conclusion: The production of TNF-alpha, MDA, cTnT, AngII and high calcium ion level of myocardiocytes in severely burned rats can be inhibited by taurine, which was beneficial in the management of myocardial injury after severe burns.