| Objective To evaluate the effect of estrogen on survival of retinal ganglion cells (RGCs) after transient retinal ischemia-reperfusionin (RIR) in rats. Methods Retinal ischemia was induced in 60 ovariectomized adult rats (OVX) by increasing introcular pressure to 100mmHg for 60 minutes via an intracameral catheter. Rats were divided into two groups that received either placebo or 17 β -estrodiol (100 μ g/kg) by a subcutaneous injection 2 hours before retinal ischemia; Every group was divided into 5 subgroups: before ischemia, reperfusion 12,24,48,72h group. The density of retinal ganglion cells (RGCs) and the thickness of the inner retinal layers were studied by HE staining method. TdT-mediated biotin-dUTP nick end labeling(TUNEL) staining technique was used to examine the RGC apoptosis after RIR in RGCs. The expression of bcl-2, bax, and caspase-3 protein in retinal cells were investigated by immunohistochemistry together with image analysis method. The mRNA expression of bcl-2, bax, caspase-3 and NF-κB in retina were investigated by real time RT-PCR together with in situ hybridization ways.Results In 17β-estrodiol-treated rats after RIR, compared with control rats, the cells in retinal ganglion layers (RGL) were higher (p<0.01); the TUNEL positive cells were much less at 24h and 48h (p<0.01). The bax, caspase-3 and NF-κB mRNA and protein in the control group were evidently higher than those in the experimental group. The bcl-2 mRNA and protein in the control group were evidently lower than those in the experimental group.Conclusions Estrogen decreases cell apoptosis with decresing bax. caspase-3 and NF-kB mRNA and protein expression and increasing bcl-2 mRNA and protein expression after RIR, this may be one of the mechanisms in which estrogen protects retinal neurons from transient ischemia-reperfusionin injury in ovariectomized rats. |
PDF Full Text Request