| 摘要: |
| 目的 探讨氯胺酮对新生大鼠认知能力及CaMKII/CREB信号通路的影响。方法 将40只新生SD大鼠随机分为4组，分别为空白组（生理盐水）、氯胺酮高（60 mg/kg）、中（30 mg/kg）和低浓度组（15 mg/kg），连续14 d腹腔注射生理盐水或不同浓度氯胺酮。末次注射24 h后，行大鼠神经功能缺陷评分；28日龄时进行Morris水迷宫实验，检测各组大鼠学习记忆能力变化。结束后采集各组大鼠海马组织，用HE染色法观察大鼠海马神经元病理形态学变化；用TUNEL法观察神经元凋亡情况；用qRT-PCR检测各组大鼠海马组织Caspase-3、Bcl-2、Bax、CaMKII和CREB mRNA表达变化；用western blot法检测各组大鼠海马组织Caspase-3、Bcl-2、Bax、CaMKII、CREB和p-CREB蛋白表达变化。结果 氯胺酮高浓度和中浓度组大鼠神经功能缺陷评分均显著性高于空白组（P＜0.01）；Morris水迷宫实验结果显示氯胺酮高浓度组和中浓度组大鼠逃避潜伏期和穿环次数与空白组相比有统计学差异（P＜0.05，P＜0.01）；HE染色结果发现氯胺酮能导致大鼠海马神经元排列松散和数目减少，并导致神经元固缩和深染；TUNEL结果显示氯胺酮能导致海马神经元凋亡；qRT-PCR和western blot结果表明，高、中浓度氯胺酮可以明显增加海马神经元caspase-3、Bax mRNA和蛋白表达，并降低Bcl-2、CaMKII、CREB、p-CREB mRNA或蛋白表达（P＜0.05，P＜0.01）结论 高剂量氯胺酮长期应用能影响大鼠的学习记忆能力，并导致神经元凋亡，CaMKII/CREB信号通路可能参与了氯胺酮诱导的神经元凋亡过程。 |
| 关键词: 氯胺酮 海马神经元 凋亡 CaMKII-CREB信号通路 新生大鼠 |
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| Effects of Ketamine on the newborn rats learning and memorye and CaMKII/CREB signaling pathway |
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| Abstract: |
| Objective: To explore the effect of ketamine on newborn rats newborn rats learning and memory and CaMKII/CREB signaling pathway. Methods: 40 newborn rats were randomly divided into 4 groups: control (saline), high (60 mg/kg), medium (30 mg/kg) and low (15 mg/kg) concentration of ketamine, all rats were injected intraperitoneally saline or ketamine for consecutive 14 d. The rats in each group were scored of neurological function at 24 h after the last administration, and the ability of spatial learning-memory was tested by Morris water maze at the age of 28 days. Morphological changes of hippocampal neurons were observed using HE staining; Apoptosis of neurons was observed by TUNEL method; qRT-PCR assays to determine the expression of Caspase-3, Bax, CaMKII, CREB and ARC mRNA and western blot assays to determine the expression of Caspase-3, Bcl-2, Bax, CaMKII, CREB, p-CREB and ARC in hippocampal tissue of newborn rats. Results: The scores of the control group are lower than high and medium concentration of ketamine group (P < 0.01). Morris staining showed that escape latency and number of puncturing of medium and high concentration of ketamine groups rats significant differences compared with the control group (P < 0.05, P < 0.01). HE staining showed that ketamine can result in loose arrangement of cells, decreased number, neuronal shrinkage and hyperchromatism in hippocampal. TUNEL showed that ketamine can induce cell apoptosis in hippocampal neurons. The results of qRT-PCR and western blot showed that the high concentration of ketamine significantly increased the expression of Caspase-3 and Bax mRNA and protein in hippocampal neurons, meanwhile, its significantly reduced the expression of Bcl-2, CaMKII, CREB and p-CREB (P < 0.05, P < 0.01). Conclusion: High dose ketamine can affect the learning and memory ability of rats and lead to neuronal apoptosis, and CaMKII/CREB signaling pathway may be involved in ketamine induced neuronal apoptosis. |
| Key words: Ketamine Hippocampal neuron Apoptosis CaMKII-CREB signaling pathway Newborn rats |