辐射致雄性小鼠不育症模型的建立及生精细胞损伤的初步分析

目的：构建辐射致雄性小鼠不育症模型,并对模型小鼠的生精细胞损伤进行初步分析。方法：不育症模型构建：65只雄性C57BL/6小鼠随机分为7组,正常对照组(A组)及6组60Co γ照射组,后者包括B组(12 Gy)、C组(6+6 Gy)、D组(10 Gy)、E组(6+4 Gy)、F组(8 Gy)、G组(4+4 Gy)。观察分析小鼠死亡情况(24w)及30、50、70 d受孕率。生精细胞损伤分析：72只雄鼠随机分为4组：正常对照组、6+4 Gy组、4+4 Gy组、6 Gy组。30、50、70 d观察睾丸组织切片(HE染色)并评估其生精功能( Johnsen评分);对PLZF阳性标记的精原干细胞(免疫组化法)计数。结果：A、E、F、G组生存时间较长,B、C组生存时间较短。30、50、70 d,D、E组受孕率均为0%。各照射组Johnsen评分均低于对照组(P<0.05);6+4 Gy组的PLZF阳性细胞计数呈逐渐上升趋势,但均明显低于对照组(P<0.05)。结论：6+4 Gy的60Co-γ射线照射7周龄的C57BL/6雄性小鼠,可以构建不育症模型。模型小鼠的PLZF标记的精原干细胞计数虽然低于对照组,但并非完全消失,提示不育症的原因并非精原干细胞的完全消亡。

Establishment of a mouse model of male infertility by radiation and preliminary analysis of the injury in germ cells

Objective: To establish a mouse model of male infertility with radiation and make a preliminary analysis of the injury in spermatogenic cells.Methods: Modeling: 65 C57BL/6 male mice were randomly divided into seven groups: Control (group A) and six60Co γ-ray exposed groups, including 12 Gy group (B), 6+6 Gy group (C), 10 Gy group (D), 6+4 Gy group (E), 8 Gy group (F) and 4+4 Gy group (G). hTe death of the mice (within 24 w) and fertility rate of the mice at 30, 50, 70 days was observed and analyzed. Analysis of the injury in germ cells: 72 C57BL/6 male mice were randomly divided into four groups, including control group, 6+4 Gy group, 4+4 Gy group and 6 Gy group. At day 30, 50, 70 of the trial, the testis paraffn sections (stained with HE) were observed and spermatogenesis evaluation (Johnsen scores) was made. hTe PLZF positive spermatogonial stem cells (by immunohistochemistry) were counted.Results:hTe survival time of group A, E, F, G was longer. hTe survival time of group B and C was the shortest. At day 30, 50, 70, the fertility rate of group D and group E was 0%. hTe Johnsen score of the exposed groups were lower than that of the control group (P<0.05); the PLZF positive cell counts of the 6+4 Gy group increased gradually, yet was less than that of the control signiifcantly (P<0.05). Conclusion:hTe double exposure of 6+4 Gy with60Co γ-ray, the model of male infertility in C57BL/6 mice was successfully established. hTe counts of the PLZF marked spermatogonial stem cells in the model mice existed, not vanished, and continued to proliferate atfer the exposure, suggesting that the mechanism of infertility was not the absence of the spermatogonial stem cells.