Microcirculatory Disturbances in Cerebral Ischemia ; Analysis of Pathophysiology and Therapeutic Approach.

1.局灶性脑缺血微循环障碍的研究沙土鼠大脑中动脉(MCA)或后交通动脉(P-COM)阻断后局部脑血流量(RCBF)和微血管长度的变化。结果：1.动脉结扎后数分钟内rCBF明显下降，30分钟或1小时后出现微血管血浆灌流障碍，随后数小时进一步恶化。微血管病变的治疗方法：在大鼠大脑中动脉闭塞模型上连续应用重组人组织纤溶酶原激活物(TPA)和铜锌超氧化物歧化酶(SOD)，观察其对脑缺血时微血管病变的影响。结果表明，静脉应用这些酶显著改善了微血管的血浆循环。高血压大鼠的微循环。在易卒中的自发性高血压大鼠(SHRSP)和年龄匹配的Wistar京都大鼠中测量单位体积的微血管长度。结果表明，自发性高血压大鼠部分脑区微血管长度明显缩短。每日服用弹性酶制剂可改善SHRSP的微血管血浆灌注量。

1. Progression of Microcirculatory Disturbance in Focal Cerebral Ischemia.Changes in the regional cerebral blood flow (rCBF) and the length of plasma-perfused microvessels were studied after occlusion of the middle cerebral artery (MCA) in rats or the posterior communicating artery (P-com) in gerbils. The data demonstrated that the rCBF decreased markedly within several minutes after arterial occlusion, while the disturbances in microvascular plasma perfusion appeared 30 min or 1 hour later which further deteriorated for the following several hours.2. Therapeutic approach to microvascular deterioration.To investigate the effects of tissue-type plasminogen activator (tPA) and Cu, Zn-superoxide dismutase (SOD) on the microvascular deterioration during cerebral ischemia, recombinant human tPA and SOD were continuously applied in rat MCA occlusion model. The results indicated that intravenous application of those enzymes significantly improved the microvascular plasma circulation.3. Microcirculation in Hypertensive Rats.The microvascular length per unit volume was measured in the strokeprone spontaneously hypertensive Rats (SHRSP) and the age-matched Wistar Kyoto rats. The data demonstarted that the microvascular length was decreased in several areas of the brain in SHRSP. Daily administrattion of elastase prepartion improved the microvascular plasma perfusion in SHRSP.