Nowicki J P, Assumel-Lurdin C, Duverger D, MacKenzie E T
Department of Biology, Laboratoires d'Etudes et de Recherches Synthélabo, Bagneux, France.
J Cereb Blood Flow Metab. 1988 Aug;8(4):462-73. doi: 10.1038/jcbfm.1988.87.
Focal cerebral ischemia in the rat was induced by occlusion of the left middle cerebral artery. The temporal evolution of regional energy metabolism was studied over the 14 days consequent to the induction of ischemia in the frontal, cingulate, parietal, and occipital cortices as well as in the striatum. Regional concentrations of adenosine triphosphate (ATP), phosphocreatine, and lactate and, in addition, glucose and the cerebral/plasma glucose ratio (C/P) were measured in the hemispheres both ipsilateral and contralateral to the occlusion. Two hours after middle cerebral artery occlusion, the biochemical changes were severe in the striatum and moderate in cortical regions. Later on (at 24 and 48 h), an overall aggravated metabolic status was noted while lactate declined and glucose markedly increased. These latter biochemical changes likely indicate a marked inhibition of the rate of glucose utilization. At 48 h, the energy reserves (ATP, phosphocreatine) of parietal cortex no longer equaled those of other cortical regions, but abruptly fell to the levels found in the striatum without any increase in lactate level. Finally, at 7 and 14 days, the levels of the various metabolites in most cortical regions returned toward control values, although signs of a depressed glucose metabolism remained. However, in both striatum and parietal cortex, ATP and phosphocreatine concentrations, although higher than those observed at 48 h, remained significantly decreased. Our present biochemical study permits the classification of these selected brain regions into three categories. First there are those that are outside the area of infarction: the frontal, cingulate, and occipital cortices. These regions show little temporal evolution of brain energy metabolism but, notwithstanding, they are regions in which glucose use would appear to be greatly depressed. Second is a region considered to be the focus of infarction: the striatum. The caudate-putamen is a region with early and profound metabolic disturbances with no final restitution. Last is the region of metabolic penumbra--the parietal cortex, in which there is a time-related exacerbation of the consequences of middle cerebral occlusion in the rat.
通过闭塞大鼠左侧大脑中动脉诱导局灶性脑缺血。在缺血诱导后的14天内，研究额叶、扣带回、顶叶和枕叶皮质以及纹状体区域能量代谢的时间演变。测量了闭塞侧和对侧半球中三磷酸腺苷（ATP）、磷酸肌酸、乳酸的区域浓度，此外还测量了葡萄糖以及脑/血浆葡萄糖比值（C/P）。大脑中动脉闭塞两小时后，纹状体中的生化变化严重，皮质区域变化中等。随后（在24小时和48小时），整体代谢状态加重，而乳酸下降，葡萄糖显著增加。这些后期的生化变化可能表明葡萄糖利用率受到明显抑制。在48小时时，顶叶皮质的能量储备（ATP、磷酸肌酸）不再与其他皮质区域相等，而是突然降至纹状体中的水平，且乳酸水平没有任何升高。最后，在7天和14天时，大多数皮质区域的各种代谢物水平恢复到对照值，尽管仍有葡萄糖代谢降低的迹象。然而，在纹状体和顶叶皮质中，ATP和磷酸肌酸浓度虽然高于48小时时观察到的水平，但仍显著降低。我们目前的生化研究允许将这些选定的脑区分为三类。首先是梗死区域以外的区域：额叶、扣带回和枕叶皮质。这些区域脑能量代谢的时间演变很小，但尽管如此，它们是葡萄糖利用似乎被大大抑制的区域。其次是被认为是梗死灶的区域：纹状体。尾状核-壳核是一个早期就有严重代谢紊乱且最终无法恢复的区域。最后是代谢半暗带区域——顶叶皮质，在该区域大鼠大脑中动脉闭塞的后果会随着时间加剧。
