诱导升压介入时间对大鼠局灶型脑缺血的影响

目的:探讨实验性脑缺血后诱导升压介入早晚对其疗效的影响。方法:通过线栓法制作大鼠大脑中动脉梗死模型,随机分为A组(梗死30 min后行苯肾上腺素升压治疗),B组(60 min后升压),C组(90min后升压),D组(120 min后升压)和E组(对照组,无升压)。缺血2.5 h后再通闭塞动脉,应用激光多普勒血流仪记录缺血区血流变化,再灌注24 h后评定梗死体积。结果:诱导升压可显著提高缺血区血流灌注(A、B、C和D组均高于E组,P均<0.05),减小脑梗死体积(A、B、C和D组均小于E组,P均<0.05);而且梗死后,诱导升压开始时间越早,效果越明显(脑血流,A组优于D组,P<0.05;脑梗死体积,A组小于C组和D组,C组小于D组,P均<0.05)。结论:大鼠大脑中动脉急性闭死后,采用苯肾上腺素升压可显著改善缺血区血流灌注,降低脑梗死体积,且诱导升压开始时间越早,效果越明显。

Effects of different beginning time of induced hypertension on experimental focal cerebral ischemia

Objective To investigate the effects of different beginning time of induced hypertension on experimental focal cerebral ischemia.Methods A total of 30 Sprague-Dawley rats who suffered 2.5 h middle cerebral occlusion were randomly divided into 5 groups: Group A(treated with phenylephrine after 30 min of middle cerebral artery occlusion),Group B(after 60 min),Group C(after 90 min),Group D(after 120 min),and Group E(control group,no phenylephrine was used).Changes of cerebral blood flow were recorded by laser Doppler flowmetry,and the volume of cerebral infarction 24 h after reperfusion was evaluated.Results The cerebral blood flow in Group A,B,C,and D were significantly improved(all P < 0.05) and the volume of cerebral infarction in these 4 groups were obviously decreased(all P < 0.05) as compared with those in Group E.In addition,cerebral blood flow in Group A was better than that in Group D(P < 0.05),the volume of cerebral infarction was less in Group A than those in Group C and D,and also was less in Group C than that in Group D(all P < 0.05).Conclusion Induced hypertension by phenylephrine before reperfusion is an effective strategy for treating focal cerebral ischemia in rats,and the earlier induced hypertension begins the better effectiveness it has.