Effects Of Estradiol Benzoate On Bcl-2and Caspase-3Protein Expression After Retinal Ischemia-reperfusion Injury

0bjectiveTo investigate the protective effects of exogenous estrogen and effects ofexpression of Bcl-2and Caspase-3protein against retinalischemia-reperfusion injury．MethodsSeventy-two SD rats were randomly divided into normalcontrol(n=8),simple ischemia-reperfusion model group(IR),estradiol benzoatetreatment group (E2+IR).In the latter two group,each sub-group wasdetermined by the time after ischemia-reperfusion:six hours,twenty-fourhours,forty-eight hours and seventy-two hours.By improving the anteriorchamber intraocular pression to set up ischemia-reperfusion model in bigrats.The Morphology change of retina tissue was detected by lightmicroscope.The changes of bcl-2, caspase-3protein were measured byimmunohistochemistry in retinal tissue.The apoptosis cells were detected byTUNEL.ResultIn the normal group,the structure of retinal tissue of big rats was clear andmorphology of retinal was normal. In the simple ischemia-reperfusion modelgroup,the organization of each layer appeared slight edema on6h. Retinalganglion cells layer (RGC)was not seen obvious empty bubble sampledegeneration,both inner nuclear layer(INL)and outer nuclear layer(ONL)cells are become mild loose,mixed and disorderly;internal plexiform layer(IPL)wasbecome edema too.The organization of each layer appeared high edema on24h. RGC layer was seen obvious empty bubble sample degeneration,bothINL and ONL cells are become loose and disorderly;IPL was become obviousedema too.after48h,the retinal tissue damage began migated,when72h theretina has been restored normal,but the whole organization has becomethinner.In theE2+IR group,the damage of the retina was significantly reducedthan IRgroup,but the tissue was thinner than the normal group.In the normalgroup,it have not the expression of Bcl-2and Caspase-3protein.But in IRgroup,the expression of Bcl-2and Caspase-3protein began to add at6hoursafter reperfusion,24hours reach the peak,48hours began to reduce,and72hours has weak expression.The expression of bcl-2in E2+IR group wereincreased significantly than IR group in all the time proints(P<0.01). Theexpression of caspase-3were significantly lower than the IRgroup in all thetime proints(P<0.01).comparision between the two groups were statisticallysignificant.Almost no apoptosis cells were expressed in the normal group.Atthe IR group, the apoptosis cells were founded at6hours,with time going,at24hours arrived the peak,then reduced gradually.But in the E2+IR group, theapoptosis cells were fewer than IR group at any time points.comparisionbetween the two groups were significant(P<0.01).ConclusionThe retina organization was injuried by Ischemia-reperfusion injury,and ithas produced a large number of apoptotic celle.Bcl-2and Caspase-3proteinhas taken participate in the retina ischemia-reperfusion injury.Estradiolbenzoate could increase the expression of Bcl-2and cut the expression ofCaspase-3protein, and inhibiting cell apoptosis, protect the retina tissue.