The Effection Of Estrogen To The Apoptosis And Expression Of Caspase-3in Retinal Ganglion Cells Of Rats With Chronic Ocular Hupertention

Objective Estrogen has been implicated in the caspase-3expression and the cellapoptpsis in chronic acute ocular hupertention retinal damaged rats. This study was to discussthe neuroprotective effect of different concentration of estrogen on chronic acute ocularhupertention retinal damage, to provide theoretical foundation for the estogen used in theclinical treatment of glaucoma.Methods Sixty healthy adult different female SD rats were randomly divided into fivegroups: group I as normal control, group II~V for the experimental group(were low,mid,and high concentrations of estrogen injection group and control group). II~V group offemale-line were ovariectomized, after the first eight days,group II-IV were injectedsubcutaneously concentration25ug/kg,50ug/kg,100ug/kg estrogen0.2ml every other day,Group V were subcutaneous injected0.2ml vegetable oil.2weeks after castration surgery,sinus venosus sclerae of II~V group of female were branded closed right eye and placedcotton fleexe saturated with0.2g/L mitomycin C under the branded closed to establish chronicocular hypertension model, then observe the intraocular pressure of each group inpreoperative, intraoperative immediatelly period and1d,1w,2w,4w, and8w after the surgen.After8weeks of chronic ocular hypertension model were made, the cell apoptosis wasevaluated by in-situ apoptosis test(TUNEL). Caspase-3protein expression was evaluated bythe immunohistochemistry, the expression of Caspase-3mRNA was also examined byRT-PCR. Resultschronic ocular hypertension models were established successfully by branding closed ratsclera vein and using cotton fleexe saturated with mitomycin C,Group II~V group IOPwas significantly improved compared with preoperation. There was a significant differencein intraocular pressure between before and after the surgery of8w (p <0.05), so that theintraocular pressure were maintain a longer time (>8w). The number of TUNEL apoptoticcells in Group II~V group and group I (normal group) compared different degrees ofincrease (p <0.05), especially in group II. the number of apoptotic cells and estrogen injectionconcentration had negative correlation in group III~V group. The expression ofcaspase-3mRNA and protein levels in group II~V group was higher than the normal group,the difference was statistically significant (p <0.05). With increased concentration of estrogeninjection,the caspase-3mRNA and protein expression levels showed a decreasing trend.ConclusionsEstrogen by reducing the expression of Caspase-3and inhibition of apoptosis, to achievethe protective effect of chronic acute hupertention retinal damage. At a certain dose range, theprotective effect of estrogen is directly proportional to the concentration.