The relationship between the protection of general mild hypothermia and expression of Bcl-2 and Bax following global cerebral ischemia-reperfusion in rat

Objective This study was designed to investigate the expression of Bcl-2 and Bax in the hippocampus and the influence of general mild hypothermia on them after ischemia-reperfusion and to probe the possible protective mechanism of mild hypothermia. Methods Transient(15min) global cerebral ischemia was induced by the four-vessel occlusion method invented by Pulsinelli. H-E staining and immunohistochemical reactions of Bax and Bcl-2 were carried out correspondingly. Results Mild hypothermia could decrease the hippocampal pyramidal cells loss and the immunoreactivity of Bax but increase the immunoreactivity of Bcl-2 in the CA 1 subfield of hippocampus. Conclusion Gerenal mild hypothermia of 33℃ lasting for 4h can protect the hippocampal pyramidal cells from ischemic damage significantly. It may be one of the mechanisms that general mild hypothermia can increase Bcl-2 immunoreactivity but decrease Bax immunoreactivity.