Objective: To investigate the intracellular distribution and the activation of mitogen-activated protein kinases (MAPKs) in myocardial cells in scalded rats.
Methods: Wistar rats were used in this study and forty of them were inflicted with 40% III degree scald on the back and eight normal ones as control. The samples of plasma and myocardial tissue were harvested at 1, 3, 6, 12 and 24 postburn hours (PBHs), and samples were also obtained from normal rats as control. The plasma CK-MB activity was determined by routine method. The activation states of all the members of MAPKs [p38 kinase, ERKs (extracellular signal-regulated protein kinases) and JNK (c-Jun N-terminal kinase)] in the myocardial tissue samples were detected by Western blotting. The tissue slides were stained by immunohistochemistry methods.
Results: Activation of p38 kinase and ERK with nuclear translocation was found postburn, especially during 1, 3 and 6 PBHs (P < 0.01). But there was no activation of JNK during 1 - 24 PBHs. The plasma CK-MB content increased at 3 PBH and reached summit at 12 PBHs (P < 0.05 - 0.01).
Conclusion: p38 kinase and ERK signal pathways might play important roles in the early postburn injury of myocardial cells, inducing myocardial injury.