Gionet T X, Warner D S, Verhaegen M, Thomas J D, Todd M M
Department of Anesthesia, University of Iowa, Iowa City 52242.
Brain Res. 1992 Jul 24;586(2):188-94. doi: 10.1016/0006-8993(92)91626-p.
Halothane anesthetized Sprague-Dawley rats underwent 10 min of bilateral carotid artery occlusion with mean arterial pressure (MAP) held at 30, 50 or 60 mmHg. Sham rats did not undergo ischemia. A 7-day recovery interval was allowed. Intra-ischemic electroencephalographic (EEG) changes, behavioral function (Days 5-7), and histologic injury (Day 7) were evaluated. Under similar conditions, cerebral blood flow was determined after 10 min ischemia by the [3H]nicotine indicator fractionation technique. EEG isoelectricity was observed in 11 of 11, 5 of 10, and 2 of 11 rats in the 30 mmHg, 50 mmHg, and 60 mmHg groups respectively. Neither passive avoidance cross-over latencies nor general motor scores were affected by intra-ischemic MAP and no differences from sham performance were observed. The per cent of CA1 neurons counted as dead (left and right hemispheres combined) was significantly affected by intra-ischemic MAP (72, 46 and 28% in the 30 mmHg, 50 mmHg, and 60 mmHg groups, respectively; P less than 0.001). A greater than 50% CA1 neuronal mortality rate was present only in those rats exhibiting EEG isoelectricity. However, the number of rats demonstrating greater than a 25% interhemispheric difference in CA1 neuronal loss was greatest in the 50 mmHg group (P less than 0.02). Hippocampal blood flow decreased in association with severity of hypotension (8 +/- 1, 35 +/- 8, and 48 +/- 2 ml/100 g/min (mean +/- S.E.M.) for 30, 50, and 60 mmHg, respectively; P less than 0.01). Again, however, the greatest variability in blood flow was observed at MAP = 50 mmHg.(ABSTRACT TRUNCATED AT 250 WORDS)
用氟烷麻醉的斯普拉格 - 道利大鼠接受了10分钟的双侧颈动脉闭塞，平均动脉压（MAP）维持在30、50或60 mmHg。假手术组大鼠未经历缺血。给予7天的恢复间隔期。评估缺血期间的脑电图（EEG）变化、行为功能（第5 - 7天）和组织学损伤（第7天）。在相似条件下，缺血10分钟后，通过[3H]尼古丁指示剂分级技术测定脑血流量。在30 mmHg、50 mmHg和60 mmHg组中，分别有11只中的11只、10只中的5只和11只中的2只大鼠出现EEG等电位。缺血期间的MAP对被动回避交叉潜伏期和一般运动评分均无影响，与假手术组表现无差异。缺血期间的MAP对计为死亡的CA1神经元百分比（左右半球合并计算）有显著影响（30 mmHg、50 mmHg和60 mmHg组分别为72%、46%和28%；P小于0.001）。只有那些出现EEG等电位的大鼠中，CA1神经元死亡率才超过50%。然而，CA1神经元损失半球间差异大于25%的大鼠数量在50 mmHg组最多（P小于0.02）。海马血流量随着低血压严重程度而降低（30、50和60 mmHg时分别为8±1、35±8和48±2 ml/100 g/min（平均值±标准误）；P小于0.01）。然而，同样在MAP = 50 mmHg时观察到血流量的最大变异性。（摘要截短于250字）
