高压氧对短暂全脑缺血再灌注大鼠脑ATP酶活性的影响

Effects of Hyperbaric Oxygen on Activities of ATPase in Brain of Rats after Transient Global Cerebral Ischemia-reperfusion

目的观察SD大鼠脑缺血再灌注后Na+-K+-ATP酶和Ca2+-ATP酶活性的动态变化以及高压氧对其的影响,为临床用高压氧治疗缺血性脑卒中提供实验依据。方法按随机数字表法将63只SD大鼠分为9组:缺血再灌注组(I/R),缺血再灌注后加高压氧处理组(HBO),上述2组分别有6h、24h、48h和96h4个时相点及假手术组(Sham-O)。以四动脉阻断法建立全脑缺血再灌注动物模型。I/R组和HBO组分别于再灌注各时相点断头取脑组织并匀浆,测定Na+-K+-ATP酶和Ca2+-ATP酶活性。结果HBO组在6h出现Na+-K+-ATP酶活性升高,其活性显著高于I/R6h组(P<0.05)和假手术组(P<0.01),在24h恢复至正常;与假手术组比较,HBO组和I/R组从48h至96h再次出现Na+-K+-ATP酶活性升高(P均<0.05),但HBO组与I/R组相应时间点比较差异无统计学意义;HBO组在6h出现Ca2+-ATP酶活性升高,与假手术组比较,差异有统计学意义(P<0.01),24h后恢复至正常;与假手术组比较,I/R组在6h和48h出现Ca2+-ATP酶活性升高,差异有统计学意义(P<0.01),在24h和96h恢复至正常水平。结论高压氧处理不仅使急性期Na+-K+-ATP酶活性升高,且加快Ca2+-ATP酶活性恢复,为高压氧治疗缺血性脑卒中作用机制提供了实验依据。

Objective To investigate the dynamic changes of the activities of Na^＋ -K^＋ -ATPase and Ca^2＋ -ATPase in brain of Sprague-Dawlay rats after transient global cerebral ischemia-reperfusion and the effects of HBO treatment after ischemia-reperfusion which will provide experimental evidence for clinical treatment with HBO for ischemic stroke. Methods Sixty-three Sprague-Dawlay rats were randomly divided into nine groups： the groups of ischemia-reperfusion（I/R） and the groups treated with hyperbaric oxygen（HBO） after ischemia-reperfusion in four phases at 6 h, 24 h, 48 h and 96 h respectively and sham operated groups （sham-O） as control. Global cerebral ischemia animal model was constructed by a modified four-vessel occlusion model originally described by Pulsinelli and Buchan. The homogenate of brain was collected respectively at each phase after ischemia-reperfusion. The activities of Na^＋ -K^＋-ATPase and Ca^2＋ - ATPase in the homogenate were measured. Results The activity of Na^＋-K^＋ -ATPase in 6 h HBO group was significantly higher than that of 6 h MI/R group（ P 〈 0.05） and sham-O group（ P 〈 0.01 ）. The activities of Na^＋ -K ^＋ -ATPase of HBO group and I/R group returned to their normal levels at 24 h（P〉0.05）. The activities of Na^＋ -K^＋ -ATPase in 48 h, 96 h HBO groups and I/R groups of corresponding phases were significantly higher than those of sham-O groups again （ P 〈 0.05 ）, but there was no statistically difference between HBO groups and I/R group of corresponding phases（ P 〉 0.05 ）. The activities of Ca^2＋-ATPase in 6 h HBO group were significantly higher than those of sham-O groups（P 〈0.01 ） and they returned to normal levels in 24 h, 48 h and 96 h HBO groups（P 〉0.05）. The activities of Ca^2＋ -ATPase in 6 h I/R and 48 h I/R groups were significantly higher than those of sham-O groups（ P 〈 0.01 ） twice and returned to normal levels in 24 h and 96 h（P〉0.05）. Conclusion The results suggest that the activities of Na^＋ -K^＋ -ATPase and Ca^2＋ -ATPase in VR groups both stepped up twice at acute and tardy phases after transient global cerebral ischemia-reperfusion. Not only the advancing extent of Na^＋ -K^＋ -ATPase activity at acute stage by hyperbaric oxygen treatment is higher than those of the corresponding I/R groups, but also Ca^2＋ -ATPase activity by hyperbaric oxygen treatment recovered faster than those of the corresponding I/R groups. These experimental results reveal the mechanism of hyperbaric oxygen treatment for ischemic stroke.