邻苯二甲酸二丁酯对青春期大鼠雄性生殖系统的影响

目的:探讨邻苯二甲酸二丁酯(DBP)对青春期大鼠雄性生殖系统的影响。方法:5周龄雄性SD大鼠用DBP灌胃染毒30d,染毒剂量包括:10、100、500mg/(kg.d),对照组仅给予溶剂(玉米油)。染毒结束后,检测睾丸、附睾、垂体、肝脏重量及脏器系数。苏木精-伊红(HE)染色法检测睾丸、附睾组织病理改变。放免法测定血清中黄体生成素(LH)、卵泡刺激素(FSH)、睾酮(T)水平。实时定量反转录PCR测定类固醇激素合成急性期调节蛋白(StAR)、增殖细胞核抗原(PCNA)、细胞色素P450胆固醇侧链裂解酶(P450scc)、清道夫受体(SR)mRNA的相对表达变化。结果:500mg/(kg.d)组中,睾丸及附睾重量明显减轻,垂体、肝脏的重量没有明显改变。100mg/(kg.d)和500mg/(kg.d)DBP导致了睾丸组织病理学改变。500mg/(kg.d)DBP组中血清T、LH水平降低,血清FSH升高。10mg/(kg.d)DBP组血清LH及FSH水平升高。500mg/(kg.d)DBP抑制了StAR、PCNAmRNA的表达。10mg/(kg.d)DBP提高了P450sccmRNA的表达水平,SRmRNA表达水平没有明显改变。结论:高剂量DBP对雄性生殖系统有明显毒性效应,较低水平的DBP改变了血清中促性腺激素LH的水平,并有可能以此来改变睾丸中P450sccmRNA的表达。

Effects of di-butyl phthalate on the reproductive system of adolescent male rats

Objective:To explore the effects of di-butyl phthalate(DBP)on the reproductive system of adolescent male rats.Methods:Sprague-Dawley(SD)rats aged 5 weeks were assigned to receive corn oil(vehicle control)or DBP orally at 10,100 and 500 mg/(kg·d)for 30 days.After the exposure,the testis,epididymis,liver and pituitary of the rats were weighted and their ratios to the body weight obtained.Histopathological changes of the testis and epididymis were examined by Hematoxylin-eosin staining,the levels of testosterone(T),luteinizing hormone(LH)and follicle stimulating hormone(FSH)in the serum were measured by radioimmunoassay,and the relative mRNA expressions of the steroidogenesis acute regulatory protein(StAR),proliferating cell nuclear antigen(PCNA),cytochrome P450 cholesterol side chain cleavage enzyme(P450scc)and scavenger receptor(SR)were detected by real-time quantitative RT-PCR.Results:DBP induced significant histopathological changes in the testicular tissue at 100 and 500 mg/(kg·d),and decreased the testicular and epididymal weights,inhibited the mRNA expressions of StAR and PCNA,reduced the levels of T and LH,and elevated the level of FSH at 500 mg/(kg·d).At the dose of 10 mg/(kg·d),DBP increased serum LH and FSH and the mRNA expression of P450scc.While the SR mRNA expression showed no significant changes in all the groups.Conclusion:High level of DBP has apparent toxic effect on reproductive system of male rats.Low-dose DBP can increase the level of serum gonadotropin LH and affect the mRNA expression of P450scc in the testis.