背景 近年的流行病学和实验研究显示雌激素对晶状体的正常代谢有保护作用,但是目前关于血清中雌激素水平对大鼠晶状体上皮细胞(LECs)雌激素受体(ER)表达影响的研究尚未见报道. 目的 观察LECs中ERα、ERβ的表达,研究不同的雌二醇给药方法对成年去势雌性Wistar大鼠晶状体代谢的影响.方法 将60只健康清洁级成年雌性Wistar大鼠分为伪手术组、去势组、去势+低剂量雌二醇点眼组、去势+高剂量雌二醇点眼组、去势+低剂量雌二醇注射组和去势+高剂量雌二醇注射组6个组,每组10只大鼠.通过大鼠卵巢切除法建立鼠去势模型,每周裂隙灯显微镜下观察各组大鼠晶状体的混浊情况.造模5个月后分别给予大鼠质量分数50％、100％苯甲酸雌二醇注射液点眼,每日4次,共6周或苯甲酸雌二醇注射液每次0.200 mg/kg、0.400 mg/kg肌内注射,每3天一次,共6周.分别于造模后5个月及给药6周后检测各组大鼠血清中雌二醇的质量浓度,给药6周后过量麻醉法处死大鼠并取其晶状体,采用免疫组织化学法检测LECs中ERα、ERβ的表达.结果 大鼠卵巢切除后各组大鼠裂隙灯显微镜下未见晶状体混浊.光学显微镜下观察,各组大鼠LECs及晶状体纤维结构均正常.术后5个月时和用药后6周各组大鼠血清雌二醇质量浓度均明显低于对照组,6个组的总体差异有统计学意义(F=15490.527,P=0.000)；用药前后大鼠血清雌二醇质量浓度有明显差异(F=943.236,P=0.001).大鼠用药6周后,去势组、去势+高剂量雌二醇点眼组、去势+低剂量雌二醇注射组LECs中ERα、ERβ表达率均明显低于伪手术组；而去势+低剂量雌二醇点眼组LECs中ERα、ERβ表达率高于去势组和去势+低剂量雌二醇注射组,差异均有统计学意义(P＜0.05).去势+高剂量雌二醇注射组LECs中ERα、ERβ表达率均接近伪手术组(ERα:28.04±6.80 vs.31.30±7.11；ERβ:25.38±5.59 vs.27.75±7.13);去势组、去势+高剂量雌二醇点眼组、去势+低剂量雌二醇注射组LECs中ERα、ERβ阳性细胞平均吸光度(A)值均明显低于伪手术组,而去势+低剂量雌二醇点眼组则较去势组和去势+低剂量雌二醇注射组明显升高,差异均有统计学意义(P＜0.05),但去势+高剂量雌二醇注射组LECs中ERα、ERβ平均A值均接近伪手术组(ERα:0.1859±0.0067 vs.0.1833±0.0087；ERβ:0.1686±0.0095 vs.0.1689±0.0059). 结论 LECs 中ERα和ERβ的表达水平与体内雌激素的水平有关.雌激素的不同给药途径对晶状体ER表达的影响不同；低剂量雌激素点眼可能优于其他高剂量雌激素给药方式.%Background Recently researches indicated that estrogen plays important role in maintaining the normal metabolism of lens. Objective This study was to investigate the changes of estrogen receptor( ER ) α and β expressions in lens upon estrogen level in castrated female rat. Methods Sixty clean adult female Wistar rats were randomized into castrated group,sham operation group,ovariectomy group,ovariectomy with low-dose estradiol eyedropping group,ovariectomy with high-dose estradiol eyedropping group,ovariectomy with low-dose estradiol injecting group and ovariectomy with high-dose estradiol injecting group,and 10 rats for each.The castrated animal models were established by ovariectomy for 5 months.Then 50％,100％ oestradiol benzoate eyedrops were used 4 times per day respectively and 0.2 or 0.4 mg/kg oestradiol benzoate were intramuscularly injected at two-day interval for 6 weeks in corresponding experimental group.Serum estradiol concentration was detected in the rats of various groups at 5 months after ovariectomy and 6 weeks after administration of estradiol benzoate.The animals were sacrificed using the excessive anesthesia method and the lenses were obtained for the assay of ERα and ERβ expressions.The use of the animals complied with the Statement of ARVO. Results No obvious opacification of lenses and the changes of structure and morphology in lens were seen in the rats of various groups under the slit lamp microscope and light microscope during the observing duration after ovariectomy.The significant differences were found in serum estradiol concentrations among the 6 groups ( F=15490.527,P=0.000) or between before and after usage of estradiol benzoate( F=943.236,P =0.001 ).Six weeks after usage of estradiol benzoate,the expressions of ERα and ERβ in the lenses were lower in the castrated group,ovariectomy with high-dose estradiol eyedropping group and ovariectomy with low-dose estradiol injecting group compared with the the sham operative group (P＜0.05),but those in the ovariectomy with low-dose estradiol eyedropping group and ovariectomy with high-dose estradiol injecting group were elevated in comparison with above groups( P＜0.05 ),and expressions of ERα and ERβ in the lenses were similar to the sham operative group ( ERα:28.04±6.80 vs.31.30±7.11 ;ERβ:27.75±7.13 vs.25.38±5.59).Mean A values of ERα and ERβ in the lenses were lower in the castrated group,ovariectomy with high-dose estradiol eyedropping group and ovariectomy with low-dose estradiol injecting group compared with the sham operative group (P＜0.05),but those in the ovariectomy with low-dose estradiol eyedropping group and ovariectomy with high-dose estradiol injecting group were elevated in comparison with above groups ( P＜0.05 ),and mean 4 values of ERα and ERβ in the lenses were similar to the sham operative group (ERα:0.1833 ±0.0087 vs.0.1859 ±0.0067; ERβ:0.1689±0.0059 vs.0.1686±0.0095). Conclusions The expressions of ERα and ERβ in the LECs are associated with the level of serum estradiol.The effects of estrogen on lens were different by different medication way.Low-dose estradiol eyedropping was a more feasible approach to the prevention of cataract.
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