The effect of general mild hypothermia on the dynamic change of Bcl-2 and Bax expressions in the hippocampus following global cerebral ischemia-reperfusion in rats

Objective To probe into the relationship between the protective effect of mild hypothermia and the expression of Bcl-2 and Bax in the hippocampus.?Methods Transient (15 min) global cerebral ischemia was induced by the four-vessel occlusion method of Pulsinelli. The hippocampal specimens were examined after H-E staining and immunohistochemical reactions for Bax and Bcl-2.?Results Mild hypothermia decreased the loss of hippocampal pyramidal cells, enhanced the immunoreactivity of Bcl-2 in the CA1 subfield of hippocampus and prolonged the expression time. But it depressed the immunoreactivity of Bax in the CA1 subfield and shortened its expression time.?Conclusion Immediate general mild hypothermia following ischemia-reperfusion for 4 h protects the hippocampal pyramidal cells from ischemic damage significantly, and this protection may be related to the upregulation of antiapoptotic protein (Bcl-2) and the simultaneous downregulation of proapoptotic protein (Bax).