[Influence of estradiol benzoate on fluid reabsorption capacity of rat efferent ductuli].

OBJECTIVE: To study the influence of estradiol benzoate (E2B) on the fluid reabsorption capacity of rat efferent ductuli. METHODS: Newborn male Sprague-Dawley rats were injected subcutaneously with E2B (0.2 mg/5 g body weight), and the histological morphology of efferent ductulus, epithelial ultrastructure, and immunoexpression of AQP-1 were investigated on postnatal day 14, 21, 28, 42 and 56, respectively. Vehicle was given to the controls. RESULTS: After exposure to E2B, the lumina of the efferent ductuli dilated greatly (P < 0.05), and the epithelium height decreased significantly (P < 0.01), microvilli of nonciliated cells short and sparse, endocytic apparatus implicated in fluid reabsorption scarce, and with no AQP-1 expression. CONCLUSION: High dosage of E2 B neonatally administrated to rats damages the fluid reabsorption capacity of efferent ductuli.

[Influence of estradiol benzoate on the testis development of rats].

OBJECTIVE: To study the influence of estradiol benzoate (E2B) on the testis development of Sprague-Dawley (SD) rats. METHODS: Newborn male SD rats were injected subcutaneously with E2B (0.2 mg/5 g body weight). At days 14, 21, 28, 42 and 56 after birth, the rats were sacrificed after anaesthesia, and their testes were taken out and weighed. The cranial and caudal SEH and TD were measured respectively, the TD/SEH ratio in each part of the testis and the caudal SEH/cranial SEH ratio were calculated, and different stages of spermatogenesis were analysed. RESULTS: In the experimental group, the testis weight was significantly lower than that of the control (P < 0.01), the testes constantly remained in the abdominal cavity, and there was much fluid retention in the rete testis all the time. From day 21 on, the TD/SEH ratio in the cranial testis was much higher than in the control (P < 0.01), and so was the caudal SEH/cranial SEH ratio (P < 0.01). And spermatogenesis was obviously retarded as compared with the control (P < 0.01). CONCLUSION: Exposure of newborn male SD rats to E2B can cause fluid retention in the testis and cryptorchid, which in turn may retard spermatogenesis.