纳洛酮对蛛网膜下腔出血大鼠海马区神经细胞自噬的影响

EFFECT OF NALOXONE ON NERVE AUTOPHAGY IN THE HIPPOCAMPUS OF RATS WITH SUBARACHNOID HEMORRHAGE

目的 探讨纳洛酮对蛛网膜下腔出血(SAH)模型大鼠的学习记忆能力及海马区神经细胞自噬的影响。方法 将36只雄性清洁级SD成年大鼠随机法分为假手术组、SAH组、纳洛酮组。采用颈内动脉穿刺法建立蛛网膜下腔出血大鼠模型,假手术组仅分离颈内动脉,但不刺破血管。造模成功后,纳洛酮组给予纳洛酮注射液(1mg/kg体重)腹腔注射,1次/12h;假手术组和SAH组给予等量生理盐水腹腔注射。术后24h进行水迷宫实验,比较三组大鼠到达平台时间;随后大鼠处死断头,取海马组织,HE染色比较神经细胞形态结构,免疫组织化学分析表达Beclin-1、LC3-Ⅱ阳性细胞个数,Western blotting法测定海马组织自噬特异性标志物Beclin-1和LC3-Ⅱ蛋白表达。结果 与假手术组比较,SAH组到达平台时间延长(P<0.05),海马区神经细胞形态结构正常的个数减少(P<0.05),表达Beclin-1、LC3-Ⅱ的细胞个数增多(P<0.05),Beclin-1、LC3-Ⅱ蛋白表达升高(P均<0.05);与SAH组比较,纳洛酮组到达平台时间缩短(P<0.05),海马区神经细胞形态结构正常的个数增多(P<0.05),表达Beclin-1、LC3-Ⅱ的细胞个数增多(P<0.05),Beclin-1、LC3-Ⅱ蛋白表达升高(P均<0.05)。结论 纳洛酮能够增强SAH大鼠海马区神经细胞自噬,减少神经细胞损伤,改善大鼠的学习记忆能力。

Objective To investigate the effect of naloxone on autophagy in hippocampal area of rats with subarachnoid hemorrhage(SAH).Methods Thirty-six male Sprague-Dawley rats were randomly divided into sham operation group( sham group),SAH group,naloxone group(SAH + naloxone group).Establishment of rat model of subarachnoid hemorrhage by internal carotid artery puncture.The sham operation group only penetrates the core into the skull along the blood vessel,but does not pierce the blood vessel.After successful modeling,the naloxone group was given naloxone injection(1 mg/kg body weight) intraperitoneally,once/12 h.The sham operation group and the SAH group were given an equal amount of normal saline intraperitoneal injection.The water maze test was performed 24 hours after operation to compare the time of reaching the plateau in the three groups.Then the rats were sacrificed and hippocampus were taken,observation of nerve cell morphology by HE staining,immunohistochemistry to detect the number of Beclin-1 and LC3-II positive cells,Western blotting to detect expression of autophagy-specific markers Beclin-1 and LC3-II protein.Results compared with the sham group,the times of escape to safe area was prolonged(P<0.05),the number of normal morphology of hippocampal nerve cells decreased(P<0.05),the number of Beclin-1 and LC3-II positive cells increased(P<0.05),the expression of Beclin-1 and LC3-II protein was increased(P<0.05) in the SAH group.Compared with the SAH group,the times of escape to safe area was shortened(P<0.05),thenumber of normal morphology of hippocampal nerve cells increased(P<0.05),beclin-1 and LC3-II positive cells were increased(P<0.05),the expression of Beclin-1 and LC3-II protein was increased(P<0.05)in the naloxone group.Conclusion Naloxone can enhance autophagy in hippocampus of SAH rats,reduce nerve cell damage,and improve learning and memory ability in rats.