被动吸烟诱导金黄地鼠神经管形成过程中细胞过度死亡

Passive smoking evokes excess cell death in embryonic golden hamster neuroepithelium during the formation of neural tube.

目的 研究被动吸烟对胎鼠神经系统发育的影响 ,探讨其致神经管缺陷的可能机制。方法 将怀孕的金黄地鼠用烟熏的方法建立被动吸烟的致畸模型 ,在体视显微镜下观察鼠胚的发育情况 ;采用甲苯胺蓝染色技术 ,观察被动吸烟对胎鼠神经上皮细胞死亡和增殖的影响。结果 被动吸烟对胚胎有显著的致畸作用 (χ2 =5 1.2 8,P <0 .0 1)。吸烟组固缩细胞数明显高于对照组 (F =2 1.95 ,P <0 .0 1) ,随着胎龄的增加固缩细胞数也有所增加 (F =2 1.4 9,P <0 .0 1) ;吸烟组的有丝分裂相计数高于对照组 (F =11.91,P <0 .0 1) ,随着胎龄的增加有丝分裂相数也有所增加 (F =70 .6 5 ,P <0 .0 1)。结论 被动吸烟可诱导神经上皮及其周围间充质细胞变性、死亡 ,导致了神经管的形成和分化异常 ,使神经管延迟闭合或不闭合。香烟烟雾能提高有丝分裂率 ,可以部分代偿由其引起的神经上皮细胞的减少 ,但不能弥补由于细胞过度死亡而导致神经管缺陷。

Objective: To sdudy the effect of passive smoking on the development of embryonic golden hamsters neuroepithelium, and to investigate the possible mechanisms of teratogenesis caused by passive smoking. Metheds: The pregnant golden hamsters were put in the selfmade chamber for passive smoking, in order to establish teratogenesis model of passive smoking. The development of embryos was observed with anatomic microscope. And the pyknotic cells and mitotic figures were counted with toluidine blue stained. Results: Passive smoking could induce teratogenesis during neurulation (χ2 =51.28,P<0.01). By counting pyknotic cells and mitotic figures, we found that the number of pyknotic cells within the neuroepithelial of passive smoking group increased more than one time compared with the control group (F=21.95,P<0.01), besides that the cell damages, we also found that of mitotic figures were higher than control group ( F=11.91,P<0.01). Conclusion: Tobacco smoking might induce excess degeneration, death, and cells loss in the neural epithelium, thereby resulting in failure of formation and differentiation of neural tube. Although enhanced mitosis could represent partial compensation for cell loss, it could not be remedied that neural tube defects were caused by the excess cell death.