目的　探讨氧自由基/JNK信号通路在慢性间歇性低氧大鼠神经损伤中的作用。  方法  　160只雄性SD大鼠随机分成对照组（n=40）、轻度间歇低氧组（n=40）、中度间歇低氧组（n=40）、重度间歇低氧组（n=40）。对照组暴露于空气中，间歇低氧组分别暴露于不同低氧条件下（100 ml/L、75 ml/L和50 ml/L，暴露时间每天8 h，持续时间2、4、6、8周），电镜观察海马区神经细胞超微结构，采用硫代巴比妥酸法检测大脑组织丙二醛(MDA)水平；免疫印迹和免疫组化法检海马区磷酸化JNK和c-fos蛋白表达水平，原位缺口末端标记法（TUNEL）检测凋亡细胞。  结果　与对照组比较，随低氧时间的延长，三组间歇性低氧组大鼠海马神经元结构损伤；MDA水平、磷酸化JNK及c-fos表达增多，TUNEL阳性细胞增多（P＜　0.05）；上述变化在重度间歇性低氧组最为显著（P＜0.05）；轻中度间歇性低氧组中MDA水平、磷酸化　JNK及c-fos和TUNEL阳性细胞6周达高峰，两组比较二者差异无统计学意义；重度间歇性低氧组MDA水平、磷酸化JNK及c-fos和TUNEL阳性细胞8周达高峰，与轻中度间歇性低氧组比较，差异显著。  结论　慢性间歇性低氧后氧自由基激活的JNK信号通路，通过调控c-fos表达介导神经细胞凋亡。

Objective　To investigate the mechanisms of oxygen free radical/JNK signaling pathway on nerve injury after different degree of intermittent hypoxia (IH) in rats.　Methods　one hundred and sixty Male Sprague-Dawley rats were randomly divided into four groups: control group（n=40），mild intermittent hypoxia group（n=40）, moderate intermittent hypoxia group（n=40），severe intermittent hypoxia group（n=40）. Rats in the control group were exposed in the air，the three intermittent hypoxia groups were exposed respectively in different intermittent hypoxia conditions:100 ml/L，75 ml/L and 50 ml/L; 8-hour-intermittent hypoxia everyday; the duration of experiment 2, 4, 6 and 8 weeks, respectively. The morphological changes were observed by electron microscopy；the malondialdehyde (MDA) contents in cortex were measured with spectrophotometry；the expressions of phosphorylated JNK and c-fos proteins were detected with immunohistochemistry and Western-Blot. The quantity of apoptotic cells was measured by terminal deoxynucleotidyl transfernase medicated nick end labeling (TUNEL) method.　Results　Compared with the control group，the ultrastructure of nerve cell nucleus was injured more severely and the phosphorylated JNK and c-fos expressions and TUNEL-positive cells numbers increased obviously in a time-dependant manner. Moreover, the abovementioned changes were more significant in severe intermittent hypoxia group. The MDA level，phosphorylated JNK and c-fos expressions and TUNEL-positive cells numbers reached peak at 6 weeks in the mild and moderate intermittent hypoxia groups and there were no significant difference between the two group； The MDA level，phosphorylated JNK and c-fos expressions and TUNEL-positive cells numbers reached peak at 8 weeks in severe intermittent hypoxia group and there was significant difference when compared with the mild or moderate intermittent hypoxia groups.　Conclusions　After intermittent hypoxia，oxygen free radical activated ERK1/2 signaling pathway played an important role in the process of nerve cell apoptosis by regulating c-fos expression.