Protective function of estradiol after cerebral ischemic reperfusion and its effect on the expression of caspase-3 in rats

Objective To study the effect of estradiol on neurocyte apoptosis and caspase-3 expression in rat focal cerebral ischemia tissue.Methods 72 Wistar rats were randomly divided into sham operation(n=8),operation control and estradiol groups. The latter two groups were further subdivided into 3, 6, 12, 24 h time points subgroups (n=8). Cerebral ischemia reperfusion model induced by left middle cerebral artery occlusion (MCAO) for 2 hours of ischemia were killed at 3, 6, 12, 24 h of reperfusion respectively. Cell apoptosis was detected by TUNEL staining. The expression of caspase-3 was determined by immunohistochemistry. Infarction volume was determined by 2,3,5-triphenyltetrazolium chloride (TTC) staining.Results Sham operation group had no infarction focus,apoptosis and caspase-3 positive cell. Comparing to operation control group, estradiol group had significantly reduced infarction size, decreased apoptosis and lessened expressions of caspase-3 (all P0.05).Conclusions Estradiol could inhibit neuronal cell apoptosis by decreasing the expression of caspase-3,playing protective role in brain.