过量碘化物诱导原代培养的大鼠仔鼠皮层神经元细胞凋亡的实验研究

Excessive iodide induces apoptosis in primary cultured cortical neurons of rats

目的观察过量碘化物对原代培养的大鼠仔鼠皮层神经元细胞凋亡的诱导作用,并对其机制作初步探讨。方法取新生0～1d的大鼠仔鼠皮层神经元培养24h后,加入不同浓度的碘化钾,采用光镜及荧光显微镜观察细胞的形态改变;流式细胞术分析DNA的降解;分光光度法检测细胞的一氧化氮(NO)含量及一氧化氮合酶(NOS)活性。结果实验组加入过量碘化物12h可见细胞形态发生改变,经荧光染色后可见凋亡细胞,染色质浓集,呈致密的斑块状或新月状,并可见凋亡小体及核碎片,48h左右达到高峰。流式细胞术分析细胞凋亡率随碘化物浓度的升高而升高。实验组细胞的NO含量及NOS活性较正常对照组增高。结论过量碘化物可以诱导原代培养的大鼠仔鼠皮层神经元细胞凋亡,并呈剂量依赖关系,其机制可能与NOS活性及NO含量增高有关。

Objective To investigate the effect of excessive iodide on apoptosis in primary cultured cortical neurons of rats. Methods After being cultured in vitro for 7 days , the cortical neurons were exposed to different concentrations of KI. The apoptosis was observed by AO - stained fluorescin; the apoptosis rate by propidium iodide - stained flow cytometry; the content of NO and NOS by spectrophotometry. Results Cortical neurons exposed to excessive iodide developed apoptotic changes of morphology such as chromatin condensation, nucleic fragmentation and the formation of apoptosis body . These changes peaked at 48 h after the treatment. Flow cytometry analysis showed that the apoptosis rates were higher gradually with the concentrations of KI. Compared with the control group, the content of NO and the activity of NOS in experimental groups were increased significantly. Conclusions Excessive iodide may induce the apoptosis in the primary cultured cortical neurons of rats and the apoptosis is concentration - dependent. The mechanism of apoptosis may be related with the increase of NO and NOS .