钾离子通道激动剂对蛛网膜下腔出血后脑血管痉挛的作用

Effect of potassium channel activator on cerebral vasospasm after subarachnoid hemorrhage

目的观察早期使用不同剂量特异性钾离子通道激活剂对蛛网膜下腔出血(SAH)后脑血管痉挛(CVS)的作用。方法将24只雄性新西兰白兔随机等分为4组:①对照组:枕大池注入生理盐水;②SAH组;③SAH+小剂量钾离子通道激活剂Cromakalin组(0.1mg/kg);④SAH+大剂量Cromakalin组(0.3mg/kg)。采用枕大池注血法建立兔SAH模型,1h后开始静脉输注Cromakalin,每12h给药1次,共4次。注血后48h采用灌注固定法处死动物动物,留取基底动脉标本,通过测定基底动脉血管横截面积来评价CVS的程度。结果基底动脉横截面积测定的结果提示SAH组较对照组明显缩小(P<0.01),而SAH+小剂量Cromakalin组及SAH+大剂量Cromakalin组均较SAH组痉挛明显改善(P<0.05)。结论早期使用特异性钾离子通道激活剂Cromakalin能改善兔SAH模型的基底动脉血管痉挛。

Objective To observe the effect of early different doses of specific potassium channel activator on cerebral vasospasm （CVS） after subarachnoid hemorrhage （SAH）. Methods Twenty-four female New Zealand White rabbits were equally randomized to four groups： ①control with injection of normal saline to the cistema magna, ②subarachnoid hemorrhage （SAH）,③SAH treated with low-dose （0.1 mg/kg） eromakalim （a specific potassium channel activator）, ④SAH treated with high-dose （0.3 mg/kg） crornakalirn. The rabbit SAH model was constructed by autologons blood injection into the cisterna rnagna. Cromakalim （0.1 or 0.3 mg/kg） was injected intravenously at 12-hour intervals beginning 1 hour after the SAH. The animals were sacrificed by perfusion-fixation and the basilar artery was taken 48 hours after the blood-injection in vivo. The cross-sectional area of each basilar arterial lumen was measured to evaluate the degree of CVS. Results The cross-sectional area of arterial lumen in SAH group was statistically significantly smaller than that of the control group （P〈0.01）, and treatment with cromakalim significantly attenuated SAil-induced vasospasm （P〈0.05）. Conclusion Early use of specific potassium channel activator can attenuate the CVS after experimental SAH in rabbits.