Little J R
Adv Neurol. 1980;28:443-57.
The sequential morphological changes following acute MCA occlusion in conscious cats were studied. The artery was occluded with a simple implanted device that resulted in immediate contralateral hemiparesis. The ischemic changes in the MCA territory developed in a diphasic fashion. Astrocytic swelling and capillary narrowing preceded the development of ischemic neuronal alterations during the primary phase. Capillary obstruction developed during the secondary phase when tissue injury was advanced. Increased vascular permeability to fluorescein was seen with 90 min of MCA occlusion and was initially confined to ischemic gray matter. Leakage of fluorescein consistently occurred with occlusion periods of 90 min and longer, whereas increased permeability to Evans blue was transient. A single, standard dose of mannitol (1.0 to 1.2 g/kg i.v.) was shown to improve the neurological deficit and delay the onset of ischemic injury. Considerable preservation of cerebral tissue was demonstrated with ischemic periods up to 6 hr. The administration of small (0.5 g/kg i.v.), repeated doses of mannitol was found to prolong the beneficial effects.
研究了清醒猫急性大脑中动脉闭塞后的一系列形态学变化。用一种简单的植入装置闭塞动脉，导致立即出现对侧偏瘫。大脑中动脉区域的缺血性变化呈双相发展。在急性期，星形胶质细胞肿胀和毛细血管狭窄先于缺血性神经元改变的出现。在组织损伤进展的二期出现毛细血管阻塞。大脑中动脉闭塞90分钟时可见血管对荧光素的通透性增加，最初局限于缺血灰质。荧光素渗漏在闭塞90分钟及更长时间时持续发生，而对伊文思蓝的通透性增加是短暂的。单次标准剂量的甘露醇（1.0至1.2 g/kg静脉注射）可改善神经功能缺损并延迟缺血性损伤的发生。在长达6小时的缺血期内，脑组织得到了相当程度的保存。发现小剂量（0.5 g/kg静脉注射）、重复剂量的甘露醇给药可延长有益效果。
