Evaluation of focal cerebral ischemia by NMR and histochemistry.

1)采用血管腔内结扎法建立自发性高血压大鼠(STIR)局灶性脑缺血模型。然后用~1H核磁共振波谱检测损伤区产生的乳酸。短暂性脑缺血乳酸升高幅度大于永久性脑缺血。超氧化物歧化酶清除剂α-苯基-N-叔丁基硝酮(PBN)可减轻短暂性脑缺血时乳酸的升高。2)观察大脑中动脉闭塞30min后大鼠脑内白细胞介素1受体拮抗剂(IL-LRA)的表达。术后1天在损伤边缘观察IL-LRA的表达，术后4天开始增强，术后7天停止表达。3)观察PBN和黄嘌呤氧化酶抑制剂奥沙普醇对沙土鼠全脑缺血的神经保护作用。双侧颈总动脉结扎3.5 mm后1周，用组织化学方法(甲酚紫染色)评价缺血神经元的损伤。脑缺血30min后给予PBN可部分减轻神经元的损伤，而氧嘌醇不能减轻神经元的损伤。这些结果表明核磁共振和免疫组织化学分析可以准确地评价药物对局灶性脑缺血的作用。

Effects of neroprotective drugs on cerebral ischemia were evaluated in animals using nuclear magnetic resonance (NMR) and immunohistochemical analyses.1) Focal cerebral ischemia was introduced in spontaneously hypertensive rats (STIR) using a method of intraluminal vascular occlusion. Then, lactate produced in the damaged area was detected by ^1H NMR.spectroscopy. The increase in lactate was larger in transient ischemia than that in permanent one. The increase in lactate in transient ischemia was attenuated by alpha-phenyl-N-tert- butyl nitrone (PBN), a superoxide scavenger.2) Expression of interleukin-1 receptor antagonist (IL- lra) was investigated in rat brain following transient focal cerebral ischemia induced by 30 min of middle cerebral artery occlusion. The expression of IL-lra was observed on the margin of the neuronal damage 1 day after operation, which was enhanced 4 days after operation and withdrawn 7 days after operation.3) Neuroprotective effects of PBN and oxypurinol, a xanthine oxidase inhibitor, were examined in gerbil global brain .ischemia. Ischemic neuronal damage were evaluated one week after a 3.5 mm bilateral carotid artery occlusion by a histochemical analysis (cresyl violet staining). PBN administered 30 min after ischemia partially attenuated the neuronal damage, while oxypurinol did not.These results indicated that the drug effects on focal cerebral ischemia were precisely evaluated using NMR and immunohistochemical analyses.