Nawashiro H, Shima K, Chigasaki H
Department of Neurosurgery, National Defense Medical College, Saitama, Japan.
J Neurotrauma. 1995 Apr;12(2):189-97. doi: 10.1089/neu.1995.12.189.
Changes in cerebrovascular dynamics were investigated immediately after closed head injury in the rat using a newly developed closed head injury model developed by Marmarou et al. Intracranial pressure (ICP) and mean arterial blood pressure (MABP) were monitored before and after trauma. Regional cerebral blood flow (rCBF), regional cerebral plasma volume (rCPV), and blood-brain barrier (BBB) permeability were measured autoradiographically with iodo[14C]antipyrine [14C]sucrose, and [alpha-14C]aminoisobutyric acid, respectively. rCBF responses to induced hypertension after trauma were measured by laser-Doppler flowmetry to investigate the status of autoregulation. Before injury, baseline ICP values ranged from 6 to 10 mm Hg in all animals. Immediately after trauma, ICP increased synchronously with MABP to > 100 mm Hg and then rapidly returned to baseline values: MABP increased rapidly by 20% after trauma and returned to baseline values within 30 sec. At 30 sec after injury, a significant increase in rCBF was observed in five subcortical regions (p < 0.05), and a significant increase in rCPV was observed in the frontal cortex, parietal cortex, thalamus, and hypothalamus (p < 0.05). At 10 min after injury, BBB permeability (the transfer constant for [alpha 14C]aminoisobutyric acid) was < 0.1 mL/kg/min for all regions except those with a relatively permeable BBB, for example, median eminence, choroidal plexus, pineal body, and pituitary gland. Induced hypertension resulted in a prolonged increase in rCBF after trauma. Thus, in this closed head injury model, which is not associated with marked hypertension or prolonged BBB disruption, widespread increases in rCBF and impaired cerebral autoregulation were apparent immediately after injury.
使用Marmarou等人开发的新闭合性颅脑损伤模型，对大鼠闭合性颅脑损伤后立即进行脑血管动力学变化的研究。在创伤前后监测颅内压（ICP）和平均动脉血压（MABP）。分别用碘代[14C]安替比林、[14C]蔗糖和[α-14C]氨基异丁酸通过放射自显影法测量局部脑血流量（rCBF）、局部脑血浆容量（rCPV）和血脑屏障（BBB）通透性。通过激光多普勒血流仪测量创伤后诱导高血压时的rCBF反应，以研究自动调节状态。损伤前，所有动物的基线ICP值在6至10 mmHg之间。创伤后立即，ICP与MABP同步升高至>100 mmHg，然后迅速恢复到基线值：创伤后MABP迅速升高20%，并在30秒内恢复到基线值。损伤后30秒，在五个皮质下区域观察到rCBF显著增加（p<0.05），在额叶皮质、顶叶皮质、丘脑和下丘脑观察到rCPV显著增加（p<0.05）。损伤后10分钟，除血脑屏障相对通透的区域（如正中隆起、脉络丛、松果体和垂体）外，所有区域的血脑屏障通透性（[α-14C]氨基异丁酸的转运常数）<0.1 mL/kg/min。诱导高血压导致创伤后rCBF持续增加。因此，在这个不伴有明显高血压或血脑屏障长期破坏的闭合性颅脑损伤模型中，损伤后立即出现rCBF广泛增加和脑自动调节受损。
