Biochemical and Electrophysiogica Aspects of Neuronal Recovery after Prolonged Ischemia of the Cat
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概要
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Complete cerebral ischemia of 30min duration was produced in normothermic cats by clamping the innominate and the left subclavian arteries and simultaneously lowering the systemic blood pressure. After ischemia the brain were recirculated with blood for periods of 15 to 2hrs. The suppression and recovery of the neuronal function during and after ischemia were assessed in the sensorimotor cortex by recording the spontaneous EEG and the pyramidal response after stimulation of the cortex; by measuring the concentration of energy metabolites, such as phosphocreatine, adenosine triphosphate, glucose, and lactate, and by measuring the DNP-stimulated ATP-ase activity of isolated mitochondria in the brain. The EEG was suppressed 11±1.4 seconds after the onset of ischemia and the pyramidal response after 240±38 seconds. At the end of ischemia, the enregy rich phosphates were completely exhausted, the glucose content had fallen to 4% of the control value, and lactate increased 23 fold. The DNP-stimulated ATP-ase activity declined 22% of the control value. The ultrastructural alteration of the sensorimotor cortex was minimum at the end of ischemia.Recovery of the pyramidal response started 3 to 6min after restoring the blood flow and was completed within 2hrs; the EEG reappeared after 1 to 2hrs. The functional recovery was related to the restoration of the energy rich phosphates and glucose-levels and to the simultaneous reduction of the accummulated lactate. Under the potimal conditions, CrP and glucose were normalized within 30min and lactate was reduced to 127% of the control value within 2hrs after the end of ischemia. The ATP concentration, and DNP-stimulated ATP-ase activity, however, returned only to 72% and less than 90% respectively, even when spontaneous EEG activity reappeared. The mitochondrial swelling which was observed as one of the structural changes of the sensorimotor cortex taken at this time, seemed to be related to the incomplete recovery of ATP concentration and DNP-stimulated ATP-ase activity.The investigation of the clinical signs of the post-recirculation recovery of the cats was carried out only with conventional nursing of the postischemic animals and no complete recovery of the clinical signs could be observed in these animals.
- 日本脳神経外科学会の論文
著者
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Kiyoshi. Sato
Max-plank-institute For Brain Reserch Department Of General Neurology
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Masashi. Kobayashi
Juntendo University School Of Medicine Department Of General Neurology
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Konstantin-alexandar. Hossmann
Max-plank-institute For Brain Reserch Department Of General Neurology