有机磷农药-敌敌畏诱导大鼠尿道下裂动物模型睾丸组织的病理学初步观察

目的:探讨环境内分泌干扰物-有机磷农药敌敌畏导致尿道下裂发生的可能机制。方法:30只SD大鼠随机分为两组:实验组(20只)和对照组(10只)。于孕12~17 d分别以敌敌畏10 mg/(kg.d)和生理盐水灌胃。实验组产雄仔鼠88只,其中22只发生尿道下裂,对照组产雄仔鼠33只,无尿道下裂发生。实验组(尿道下裂鼠)和对照组各5只仔鼠喂养至性成熟,取其睾丸组织作常规石蜡切片分别用HE染色和用抗大鼠Calretin in抗体作SP免疫组化染色检测。结果:尿道下裂大鼠睾丸组织中间质细胞(Leyd ig)数量明显减少,生精小管数及形态无明显改变;尿道下裂大鼠睾丸组织中Calretin in阳性的Leyd ig细胞数明显少于对照组。结论:孕SD大鼠染毒敌敌畏农药后能导致雄性仔鼠睾丸组织中的Leyd ig细胞数量减少,推测环境内分泌干扰物质敌敌畏诱导大鼠尿道下裂发生的可能机制是敌敌畏的毒性作用致使胎鼠睾丸中的Leyd ig细胞受损,导致胎鼠睾丸产生的睾酮水平降低,在尿道形成过程中发生障碍而产生尿道下裂。

Pathological Changes in the Testes of the Rats with Hypospadia Induced by Dichlorvos

OBJECTIVE: To study the mechanism of dichlorvos leading to hypospadia of rats. METHODS: From the 12th to the 17th day of conception, 20 pregnant female rats (the experiment group) were given 10 mg/(kg x d) dichlorvos, while another 10 (the control group) administered 1.5 ml 0.9% NaCl/day. Out of 88 male newborns of the 20 experimental mother rats, 22 had hypospadia, while out of the 33 male newborns of the 10 controls, none had the problem. Five hypospadia newborns from the experiment group and another 5 normal ones from the control group were raised to sexual maturity, and then their testes were excised and embedded in paraffin, and the tissue sections were analyzed by regular HE staining and SP immunohistochemical staining with Calretinin. RESULTS: HE staining showed that the number of Leydig cells in the testis tissues of the hypospadia rats decreased significantly compared with the normal ones, but no change was observed either in the number or in the morphology of the seminiferous tubules. Moreover, the Calretinin positive Leydig cells were reduced dramatically in the testes of the hypospadia rats. CONCLUSION: Pregnant female rats, when exposed to dichlorvos, may cause reduction of testis Leydig cells in their male offsprings. Thus the probable mechanism of rat hypospadia induced by dichlorvos may lie in the decrease of the testosterone level caused by damage to Leydig cells from dichlorvos toxicity.