大鼠短暂全脑缺血再灌后谷氨酸透过血脑屏障的变化  

Glutamate transport across blood brain barrier after transient global ischemia/reperfusion in rats

作　　者：刘晓东[1] 刘国卿 

机构地区：[1]中国药科大学药代研究中心,江苏南京210009

出　　处：《中国病理生理杂志》2000年第12期1263-1266,共4页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目! (No .39870 885 )

摘　　要：目的 :观察大鼠前脑短暂缺血再灌后谷氨酸 ([3 H]-Glu)透过血脑屏障的变化。方法 :在双侧颈总动脉阻断加低压造成大鼠前脑缺血 10min ,再灌不同时间后 ,iv [3 H]-Glu ,分析 [3 H]-Glu在海马、皮层和纹状体中单向速率转运常数 (Ki)以及测量脑皮层内注射 [3 H]-Glu后的回收率。结果 :脑缺血再灌 0 17、2、6h后 ,[3 H]-Glu在海马和皮层中的Ki显著低于对照组 (P <0 0 5 )。在对照组 ,测得脑皮层内注射 [3 H]-Glu 5min后回收率为 2 3.83% ,提示在血脑屏障上存在 [3 H]-Glu外排系统 ,这种外排不被 2 0 0mg/L丙磺舒所抑制。测得脑缺血 10min再灌 2h后 ,[3 H]-Glu的回收率 13 13% ,显著低于对照组 (P <0 0 5 ) ,表明脑缺血再灌促进Glu的外排。结论 :脑缺血再灌后 ,降低外周Glu进入脑内的速率 ,促进脑内Glu外排。AIM: to study the change of glutamate(Glu) transport across blood brain barrier(BBB) in rat following forebrain ischemia/reperfusion. METHODS: BBB unidirectional transfer constant(K i) for [3H]-Glu in rat hippocampus, cerebral cortex and striatum were determined after rats were subjected to cerebral ischemia 10 min (two-carotid occlusion plus hypovolemic hypotension) followed by 0.17, 2, 6 and 24 h of reperfusion. The recovery of [3H]-Glu in cerebrum was also determined after intracerebral injection of [3H]-Glu in another experiment. RESULTS: Compared with control rat brain, K i for [3H]-Glu significantly(P<0.05) decreased at 10 min cerebral ischemia followed by 0.17, 2 and 6 h of reperfusion. At 5 min after intracerebrally injecting [3H]-Glu , recovery of [3H]-Glu in control rat brain was 23.83%. The result indicted that there is a Glu efflux mechanism on BBB. This efflux was not significantly inhibited by pretreatment of 200 mg/L probenecid. After 10 min cerebral ischemia followed by 2 h of reperfusion, the recovery(13.13%) was significantly lower than contro(P<0.05), its recovery was only 55% of the control. The result indicated that cerebral ischemia/reperfusion may enhanced the efflux of [3H]-Glu from brain. CONCLUSION: Cerebral ischemia/reperfusion significantly reduced Glu BBB transport from plasma to brain and enhanced efflux of Glu from brain.

关 键 词：谷氨酸盐类 血脑屏障 暂时性脑缺血 再灌注损伤 

分 类 号：R743.31[医药卫生—神经病学与精神病学]