p,p’-DDE对青春前期大鼠睾丸组织氧化应激及凋亡的影响

Effects of p,p'-DDE on Oxidative Stress and Apoptosis in Testis of Prepubertal Male Rats

目的研究p,p’-DDE对青春前期大鼠睾丸组织氧化应激及凋亡的影响。方法将健康清洁级22日龄雄性SD大鼠25只按体重随机分为5组,分别为对照组(玉米油)、低(20mg/kg)、中(60mg/kg)、高(100mg/kg)剂量p,p’-DDE染毒组和VitE干预组(100mg/kgp,p’-DDE+100mg/kgVitE),每组5只。采用腹腔注射方式进行染毒,注射容积为10ml/kg,每隔1d染毒1次,共10d。染毒结束后,处死动物,取睾丸称重,并计算睾丸脏器系数;将睾丸制备组织切片和组织匀浆,分光光度计法测定大鼠睾丸组织超氧化物歧化酶(SOD)活力、丙二醛(MDA)含量和谷胱甘肽过氧化物酶(GSH-Px)活力,采用TUNEL法检测睾丸组织的细胞凋亡情况。结果各组动物染毒前体重及染毒期间体重变化无差异。大鼠睾丸重量及其脏器系数间比较,差异无统计学意义(P>0.05)。与对照组比较,高、中、低剂量p,p’-DDE染毒组SOD活力降低,中、高剂量p,p’-DDE染毒组MDA含量升高,高剂量p,p’-DDE染毒组GSH-Px活力下降,差异均有统计学意义(P<0.05)。与高剂量p,p’-DDE染毒组比较,VitE干预组SOD活力升高,差异有统计学意义(P<0.05)。VitE干预组和高剂量p,p’-DDE染毒组MDA含量和GSH-Px活力间比较,差异无统计学意义(P>0.05)。高、中、低剂量p,p’-DDE染毒组和对照组均有睾丸细胞凋亡情况发生,对照组中凋亡细胞稀少;随着p,p’-DDE染毒剂量的升高,凋亡细胞数也逐渐增多,以精原细胞和精母细胞为主,伴有支持细胞。与对照组比较,高、中、低剂量p,p’-DDE染毒组的细胞凋亡指数均升高,差异有统计学意义(P<0.05);VitE干预组的细胞凋亡指数低于高剂量p,p’-DDE染毒组,差异有统计学意义(P<0.05)。结论p,p’-DDE可通过引发睾丸组织氧化应激而诱导细胞凋亡。

Objective To study the effects of p, p＇-DDE on oxidative stress and apoptosis in testis of prepubertal male rats. Methods Twenty-five male SD rats were randomly divided into 5 groups,one control group （corn oil）, three p,p＇-DDE groups （20,60,100 mg/kg） and one interference group（ 100 mg/kg Vit E ＋ 100 mg/kg p,p ＇-DDE ） respectively by intraperitoneal injection for 10 days,and the volume of injection was 10 ml/kg. After 10 days of treatment,the rats were sacrificed and the testes were weighted, then homogenates and histological sections were prepared. The levels of SOD, MDA, GSH-Px were measured with the assay kit,and the apoptosis was determined by TUNEL Results Compared with the control group, no significant changes in body weight and organ coefficient of testes were seen. The activities of SOD were decreased in groups of 20,60,100 mg/kg p,p＇-DDE,and the concentrations of MDA were increased in groups of 60,100 mg/kg p,p ＇-DDE. The GSH-Px level was decreased in group of 100 mg/kg p,p＇-DDE. The apoptosis of testicular cells was induced in groups of 20,60,100 mg/kg p,p＇-DDE,and Vit E could decrease the oxidative stress and apoptosis successfully. Conclusion p,p＇-DDE may induce the apoptosis of rat testis cells by oxidative stress, which can be reduced by Vit E.