脑缺血再灌注期间羟自由基的来源及对亚低温的影响

The resources of hydroxyl radicals generation during cerebal ischemia/reperfusion and the effect of mild hypothermia

目的 研究亚低温对脑缺血再灌注期间纹状体多巴胺和ＡＴＰ含量和羟自由基产生的影响。方法 沙土鼠前脑缺血再灌注模型，脑缺血１０ 分。３２ 只沙土鼠随机分为假手术组、缺血组、缺血再灌注组和亚低温组。应用高效液相测定纹状体多巴胺、ＡＴＰ和海马羟自由基（ＯＨ·）的含量。结果 脑缺血１０分，缺血组海马２，３ＤＨＢＡ 的含量明显高于假手术组（Ｐ＜ ００１）。再灌注６０ 分时，缺血再灌注组２，３ＤＨＢＡ的含量明显高于假手术组（Ｐ＜ ００１），但亚低温组２，３ＤＨＢＡ 含量明显低于缺血再灌注组（Ｐ＜ ００５）。脑缺血后纹状体ＡＴＰ含量较缺血前明显下降，但再灌注６０ 分时有所恢复。再灌注６０ 分时，亚低温组纹状体ＡＴＰ含量明显高于缺血再灌注组（Ｐ＜ ００５）。脑缺血后纹状体多巴胺含量较缺血前明显下降，但再灌注６０ 分时有明显恢复。再灌注６０ 分时，亚低温组纹状体多巴胺含量明显高于缺血再灌注组（Ｐ＜ ００１）。结论 亚低温可能通过抑制脑缺血再灌注期间纹状体多巴胺的释放和促进ＡＴＰ含量的恢复而减少羟自由基的产生。

Objective To study the effect of mild hypothermia on dopamine and ATP content in striatum and hydroxyl radical (OH·) output in hippocampus during cerebral ischemia/reperfusion Methods Cerebral ischemia was induced by occlusion of bilateral common arteries for 10 min in gerbils Animals were divided into four groups:sham operated group (SH),ischemic group (IS),ischemia/reperfusion group (IR) and mild hypothermic group (MH) OH·output,dopamine and ATP contents were specifically identified and determined by high performance liquid chromatography Results In IS group,OH· output was much more than that in SH group (P<0 01),in MH group,was much less than that in IR group (P<0 01) In IS group,ATP content was much less than that in SH group (P<0 01) In MH group,ATP content was much more than that in IR group (P<0 05) In IS group,dopamine content was much less than that in SH group (P<0 01) In MH group,dopamine content was much more than that in IR group (P<0 01) Conclusion Mild hypothermia can reduce hydroxyl radicals generation by inhibiting the release of dopamine and quickening the recovery of ATP in striatum during cerebral ischemia/reperfusion,which may be one of mechanisms reducing cerebral ischemia/reperfusion injury