Pathophysiology of Hypermia and Effects of Reducing Blood Flow at the Immediate Post-Ischemia in the Brain.

高血症的病理生理学和脑缺血后立即减少血流量的影响。

• 批准号: 01570866
• 负责人: TATEISHI Akio
• 金额: $ 1.28万
• 依托单位: Yamaguchi University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01570866/
• 关键词: Brain ischemia; Reperfusion; Transorbital occlusion of middle cerebral artery; Blood-brain barrier; Vasogenic cerebral edema; 脳充血; 虚血性脳障害; 虚血後再灌流

It has been known that during a reperfusion period following transient ischemia cerebral blood flow remarkably increases from the pre-ischemic level. Although this post-ischemic hyperemia can occur in clinical situations such as cerebrovacs ular surgery, neither pathophysiologic significance of this phenomenon nor effects of therapeutic measures to suppress hyperemia have been extensively studied. Therefore, we examined the influences of induced hypotension during the immediate post-ischemic period upon cerebral blood flow, blood-brain barrier function, and neurologic outcome. (Methods) The middle cerebral artery was exposed by a transorbital approach using a surgical microscope in 27 adult cats anesthetized and mechanically ventilated. In the first series of experiment, the regional Cerebral Blood Flow (rCBF ; hydrogen clearance method), extracellular potassium ion (Kec ; electrometer technique), and electroencephalogram were recorded, while the middle cerebral artery was occluded for … More three hours and then released for two hours. Following a reperfusion period of two hours, Evans blue penetration index was calculated in slices of fixed brain samples. In the second series of experiment, neurologic deficits were scored at 48 hours after a 3 hours cerebral ischemia. In both series, animals were grouped according to the method of hemodynamic management at reperfusion ; without specific control=A, A', controlled with halothane=B, B', and controlled with pentobarbital=C, C'. (Results) Mean arterial blood pressure was significantly reduced by 20 to 35mmHgin groups B/B' and C/C', compared to groups A/A'. However, post-ischemic rCBF was not significantly different between groups. The mean Evans blue penetration index was 232, 93, and 26, in groups A, B, and C, respectively. The difference of the index between groups A and C was statistically significant. Neurological deficit score was significantly greater in group A' than in groups B' and C'. (Discussion) These results suggest that hemodynamic management by induced hypotension reduces penetration of plasma protein, and hence the development of vasogenic brain edema at reperfusion following a transient cerebral ischemia. Neurologic outcome was also improved by induced hypotension. However, hyperemic responses were not always suppressed by reduction of systemic blood pressure. Further studies were necessary to clarify the relationship between blood pressure and rCBF at the immediate reperfusion and the effects of other hypotensive agents or hypocapnia. Less

已经知道，在短暂缺血后的再灌注期间，脑血流量从缺血前水平显著增加。虽然这种缺血后充血可能发生在临床情况下，如血管外科手术，既没有这种现象的病理生理意义，也没有抑制充血的治疗措施的影响进行了广泛的研究。因此，我们研究了缺血后即刻控制性降压对脑血流量、血脑屏障功能和神经功能结局的影响。方法27只麻醉机械通气的成年猫，在手术显微镜下经眶入路暴露大脑中动脉。在第一系列实验中，记录了局部脑血流量（rCBF ;氢清除法）、细胞外钾离子（Kec ;静电计技术）和脑电图，同时闭塞大脑中动脉， ...更多信息 三个小时，然后释放两个小时。在两小时的再灌注期后，在固定的脑样品的切片中计算伊文思蓝渗透指数。在第二系列实验中，在3小时脑缺血后48小时对神经功能缺损进行评分。在两个系列中，根据再灌注时的血流动力学管理方法对动物进行分组;无特定对照=A、A '，氟烷对照=B、B'，戊巴比妥对照=C、C '。（结果）B/B'组和C/C'组的平均动脉压较A/A '组降低20 ~ 35 mmHg。然而，缺血后rCBF在组间无显著差异。A、B和C组的平均伊文思蓝渗透指数分别为232、93和26。A、C两组间各项指标差异有统计学意义。A'组神经功能缺损评分显著高于B'和C '组。（讨论）这些结果表明，通过控制性降压进行血流动力学管理可减少血浆蛋白的渗透，从而减少短暂性脑缺血后再灌注时血管源性脑水肿的发生。控制性降压也改善了神经功能结局。然而，充血反应并不总是抑制全身血压的降低。进一步的研究是必要的，以澄清血压和rCBF之间的关系，在立即再灌注和其他扩张剂或低碳酸血症的影响。少

项目成果

立石 彰男,石川 敏三,永井 郁夫,坂部 武史: "再潅流後の脳浮腫に対する低血圧.過換気の効果" 麻酔.

Akio Tateishi、Toshizo Ishikawa、Ikuo Nagai、Takeshi Sakabe：“低血压对再灌注后脑水肿的影响。过度通气的影响”麻醉。

Tateishi A, Ishikawa T, Nagai I, Sakabe T: "Induced hypotension and hypocapnia and cerebral edema at reperfusion period following ischemia. Masui"

Tateishi A、Ishikawa T、Nagai I、Sakabe T：“缺血后再灌注期诱发低血压、低碳酸血症和脑水肿。Masui”

Tateishi A,Sakabe T,Ishikawa T,Nagai I.: "Effects of hypotension and drugーinduced suppression of postーischemic hyperemia on neurologic and histopathologic outcome in cats." Stroke(in preparation).

Tateishi A、Sakabe T、Ishikawa T、Nagai I.：“低血压和药物诱导的缺血后充血抑制对猫中风神经和组织病理学结果的影响（准备中）。”

Akio Tateishi,et al.: "Effects of hypotension and drug-induced suppression of post-ischemic cerebral hyperemia on neurologic and bistologic outcome." Stroke.

Akio Tateishi 等人：“低血压和药物诱导的缺血后脑充血抑制对神经系统和生物学结果的影响。”

立石 彰男,石川 敏三,永井 郁夫,坂部 武史: "再潅流後の脳浮腫に対する低血圧,過換気の効果" 麻酔.

Akio Tateishi、Toshizo Ishikawa、Ikuo Nagai、Takeshi Sakabe：“低血压和过度通气对再灌注后脑水肿的影响”麻醉。