【摘要】 目的探讨镉对大鼠精子损伤及茶多酚(TP)的保护作用。方法 50只清洁级SD系成年雄性大鼠,随机分为阴性对照组、模型组和TP干预组(50,100,200mg/kg)。模型组和各干预组以CdCl2腹部皮下注射染毒5周,干预组分别给予50,100,200mg/kg TP灌胃。干预结束后取大鼠血、睾丸、附睾等组织进行相关指标的测定。结果 (1)与阴性对照组比较,模型组大鼠精子计数减少80%,精子活动率下降74%,精子畸形率升高6倍,血清睾酮水平下降50%;与模型组比较,100,200mg/kg TP干预后上述指标均有所改善,差别具有统计学意义。(2)与阴性对照组比较,模型组大鼠精液镉含量增加40倍,睾丸组织丙二醛含量(MDA)升高1倍,超氧化岐化酶(SOD)活力降低50%;与模型组比较,100及200mg/kg TP干预组大鼠精液镉含量降低,SOD活力提高,睾丸组织MDA含量下降。(3)与阴性对照组比较,彗星试验显示模型组大鼠睾丸细胞拖尾率增加13倍,拖尾细胞尾长明显增加;与模型组比较,TP各干预组拖尾率和尾长均有所下降。结论茶多酚可拮抗镉致大鼠精子损伤作用,其机制可能与其促进镉排出、抗氧化和修复DNA损伤有关。更多还原

【Abstract】 Objective To study the protective effects of tea polyphenols(TP) on cadmium-induced sperm toxicity in rats.Methods Fifty male adult Sprague-Dawley rats were randomly divided into 5 groups.Rats of model group and three TP groups were injected with cadmium at a dosage of 0.4 mg/kg.Animals of TP groups were simultaneously given TP at a dosage of 50,100 and 200 mg/kg respectively,once a day.After five weeks,samples of blood,testis and epididymis from all animals were collected for further analysis.Results(1) Compared to negative control group,the sperm concentration and sperm viability decreased by 80 percent and 74 percent respectively,the sperm malformation rate increased by 6 folds,the serum testosterone level decreased by 50 percent in model group.Compared to model group,those parameters from 100 and 200 mg/kg TP groups were partially recovered(P<0.05);(2) Compared to negative control group,cadmium accumulation in the semen increased by 40 folds,MDA content increased by 1 fold,the activity of SOD was inhibited by 50 percent in model group.Compared to model group,animals treated with middle and high dose TP had lower cadmium concentration in semen,lower MDA level and higher SOD activity in testis.(3) In comet assay,13 fold more testicular cells from model group had distinctive longer tails compared to negative control group;however numbers for 50,100 and 200 mg/kg TP group animals were significantly lower than that of model group.Conclusion TP show protective effects on cadmium-induced sperm toxicity in male rats.The underlying mechanisms may link to their functions in promoting cadmium excretion,inhibiting oxidative stress and repairing damaged DNA.更多还原