摘要
目的观察缺血过程中亚低温对大鼠脑缺血再灌注后缺血核心区皮质内单核细胞趋化蛋白(MCP)-1mRNA和蛋白质含量的影响。方法将60只雄性Wistar大鼠随机分为常温组(37℃)和亚低温组(32～33℃),以半定量逆转录PCR(RT-PCR)法测定MCP-1mRNA的表达,ELISA法测定缺血2 h再灌注不同时间缺血核心区脑皮质内MCP-1含量的变化,2,3,5三苯基四氮唑(TTC)染色法观察脑皮质梗死灶的变化并对大鼠进行神经病学评分。结果缺血2hMCP-1mRNA表达明显升高,再灌注后16h达高峰,此后仍维持较高水平的表达,直至再灌注后48 h;MCP-1含量于再灌注后6h开始升高,至48h逐渐达到高峰。亚低温能显著抑制再灌注后6h和16 hMCP-1mRNA的表达(P <0.05),但对再灌注后24h和48hMCP-1mRNA的表达无影响(P >0.05);亚低温能显著抑制再灌注后6h及48h脑皮质内MCP-1含量的升高(P <0.05)。亚低温组的脑梗死灶面积和神经病学评分较相应时间点的常温组明显减小。结论抑制缺血再灌注后脑皮质内MCP-1mRNA的表达和蛋白质分泌可能是亚低温发挥脑保护作用的重要途径之一。
Objective To study the effect of intraischemic mild hypothermia on the mRNA and protein levels of monocyte chemoattractant protein (MCP)-1 in the rat cortical ischemic core after transient focal cerebral ischemia. Methods The sixty male Wistar rats were randomly assigned to normothermic (37℃) or mild hypothermic (32-33℃) groups,and subjected to the right middle cerebral artery occlusion for two hours, then killed at 0, 6, 16, 24 and 48 hours after reperfusion. The mRNA level of MCP-1 was observed by half-quantitative RT-PCR. The protein level of MCP-1 was measured by enzyme linked immunosorbent assay (ELISA). The cortical infarct sizes were observed by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining reaction,and the rats were also given neurological evaluation. Results The mRNA level of MCP-1 was increased at 2 hours after ischemia, and peaked at 16 hours until 48 hours after reperfusion. The protein level of MCP-1 was markedly increased at 6 hours in the ischemic core of cerebral cortex, and peaked at 48 hours after reperfusion. The mild hypothermia could decrease the MCP-1 mRNA expression at 6 and 16 hours after reperfusion (P < 0.05), but had no effect on the MCP-1 mRNA expression at 24 and 48 hours after reperfusion (P > 0.05). The protein level of MCP-1 in the mild hypothermic groups was significantly lower than that in the normothermic groups at 6 and 48 hours after reperfusion (P < 0.05). In addition, the cortical infarct sizes and neurological scales in the mild hypothermic groups were much smaller than those in the corresponding normothermic groups. Conclusion These findings suggest that reducing the mRNA and protein levels of MCP-1 in the cerebral cortex after ischemia-reperfusion may be one of the most important ways for the neuroprotective effects of mild hypothermia.
出处
《中国微侵袭神经外科杂志》
CAS
2004年第5期215-218,共4页
Chinese Journal of Minimally Invasive Neurosurgery
基金
黑龙江省教育厅科学技术基金资助项目(10511060)
黑龙江省青年基金资助项目(QC02C32)
