雌激素替代抑制萘诱导去卵巢大鼠的晶状体氧化损伤

背景:抗氧化作用可能是雌激素对晶状体保护作用的机制之一,但此机制的具体途径目前仍不明确,同时临床上常用的几种雌激素替代治疗方法对晶状体氧化损伤的影响至今少见报道。目的:观察雌二醇及其联合孕酮对萘诱导去卵巢雌性大鼠晶状体氧化损伤模型中晶状体混浊情况、晶状体氧化防御系统、脂质过氧化产物及可溶性蛋白水平的影响。方法:将SD大鼠随机分为假手术组、模型组、雌二醇组、雌二醇+孕酮组,后3组均行双侧卵巢切除。术后2周,4组均用萘混悬液灌胃,定期行裂隙灯显微镜检查观察各组大鼠晶状体变化;灌胃6周后检测晶状体氧化防御系统、脂质过氧化产物及可溶性蛋白水平,测定血清雌二醇和孕酮水平。结果与结论:与模型组相比,雌二醇组、雌二醇+孕酮组及假手术组晶状体混浊程度轻,出现时间晚,而晶状体超氧化物歧化酶、谷胱甘肽、维生素C,可溶性蛋白含量,血清雌二醇与孕酮水平增高(P<0.05或P<0.01),丙二醛水平降低(P<0.05)。结果证实,雌二醇及其联合孕酮两种替代治疗方法对萘诱导去卵巢雌性大鼠晶状体的氧化损伤均有抑制作用,其机制与晶状体氧化防御系统的活性、抑制脂质过氧化产物的形成并维持可溶性蛋白的水平有关,抑制晶状体的氧化损伤是雌激素替代治疗发挥晶状体保护作用的机制之一。

Inhibitory effect of estrogen replacement therapy on naphthalene-induced oxidative damage of the lens in ovariectomized female rats

BACKGROUND:The primary research indicated that anti-oxidation may be one of mechanisms of protective effects of estrogen to lens,but the pathway is indefinite,and the effect of clinical methods of estrogen replacement therapy for oxidative damage on lens was reported seldom before.OBJECTIVE:To investigate the effects of estradiol and estradiol combined with progesterone on lens in opacity,oxidative defense system status,as well as its lipid peroxidative product and soluble protein levels of naphthalene-induced cataract in ovariectomized female rats,also discuss the effects and mechanisms of two clinical methods of estrogen replacement therapy for oxidative damage on lens.METHODS:Thirty-two adult female Sprague-Dawley rats were divided into four groups randomly:control,model,estradiol,and estradiol combined with progesterone.All rats were prepared for ovariectomized models except that of the control group.After 2 weeks of operation,all rats in each group were received naphthalene for 6 weeks through a stomach tube.The changes of lenses were observed with slit-lamp microscope.After 6 weeks of naphthalene administration,all rats were killed and serum estradiol and progesterone levels were determined with radioimmunoassay in each rat.The rats lenses were taken out and the levels of lens oxidative defense system and soluble protein were examined with biochemical technique.RESULTS AND CONCLUSION:Compared to the control group,opacity of lens were slight and late in estradiol and estradiol combined with progesterone groups,the level of SOD,GSH,vitamin C and soluble protein were increased(P < 0.05),while the levels of MDA was decreased(P < 0.05).In addition,the level of serum estradiol and progesterone increased significantly(P < 0.01).But there was no significant difference among estradiol,estradiol combined progesterone in all testing items.Both estradiol and estradiol combined with progesterone have inhibitory effect on naphthalene-induced oxidative damage of the lens in ovariectomized female rats,this effect may be performed through promoting antioxidative defense system activity,also reducing lipid peroxidative products,maintaining the level of soluble protein of lens.This inhibitory effect is one of the mechanisms of estrogen protective effects of estrogen replacement therapy on the lens.