新生期邻苯二甲酸二丁酯染毒对小鼠睾丸结构及精子发生调控基因Boule表达的影响

Effects of neonatal dibutyl phthalate exposure on histology of testis and the expression of Boule gene

目的研究新生小鼠暴露于邻苯二甲酸二丁酯(Dibutyl phthalate,DBP)对雄性小鼠睾丸组织结构的损伤作用以及对小鼠精子发生的影响。方法怀孕ICR母鼠分娩后,将新生小鼠随机分为对照组和DBP组,每组12只。新生仔鼠从第1天开始每天颈背部皮下注射给药(DBP 100 mg/kg·bw)或溶剂(玉米油),直至出生第35天终止给药,取6只小鼠分离其睾丸组织,剩余6只继续饲养至70 d后分离其睾丸组织及附睾。检测附睾尾精子数量及活率并通过苏木素-伊红(HE)染色法观察小鼠睾丸组织结构的变化情况,Western blot和RT-PCR检测睾丸中Boule蛋白和Boule mRNA表达量的变化情况。结果与对照组相比,出生第70天的DBP组精子数量下降,精子活率降低,差异具有统计学意义(P<0.05)。与对照组相比,第35天和第70天的DBP组睾丸生精小管直径和生精上皮厚度降低且生精小管管腔直径明显增大,差异具有统计学意义(P<0.05);第35天和第70天的DBP组睾丸中Boule基因的表达产物mRNA和蛋白水平下降,差异具有统计学意义(P<0.05)。结论新生期暴露于DBP会损伤小鼠睾丸组织结构,抑制睾丸组织内Boule基因的表达,进而影响精子发生。

Objective To study the damage of testicular tissue and the effect on spermatogenesis in male mice exposed to dibutyl phthalate during neonatal period. Methods After delivery of pregnant ICR mice, the newborn mice were randomly divided into control and DBP groups with twelve mice in each group. Newborn mice were administrated with corn oil or DBP(100 mg/kg·bw) by subcutaneous injection into fatty layer of tissue under the cervicodorsal skin. The administration was terminated on the 35 th day of birth and six mice were separated the testis tissue, and the remaining six mice were kept till to 70 th day and the testis tissue and epididymis were collected. The sperm quality of the epididymis was detected and the morphology of mouse testis was observed by hematoxylin and eosin staining. The expressions of Boule mRNA and protein in testis were detected by RT-PCR and Western blot. Results Compared with the control group, the sperm count and the sperm viability of the DBP group on the 70 th day of birth decreased, the difference was statistically significant(P<0.05). Compared with the control group, the DBP group on 35 th day and 70 th day had reduced the thickness of the testicular seminiferous epithelium and the diameter of the seminiferous tubule, and the diameter of the seminiferous tubule lumen increased significantly, the difference was statistically significant(P<0.05). The expression of mRNA and protein of Boule gene in the testis of DBP group on the 35 th day and 70 th day decreased, the difference was statistically significant(P<0.05). Conclusion Exposure to DBP during the neonatal period can damage the testicular tissue structure of mice and inhibit the expression of the Boule gene in the testis tissue,thereby effect spermatogenesis.