著者

宮崎 學

出版者

社団法人日本循環器学会

雑誌

日本循環器學誌 (ISSN:00471828)

巻号頁・発行日

vol.22, no.11, pp.822-831, 1959-02-20

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The CERO_2,composite factor of the balance of supply and demand of oxygen in the brain, not only expresses the presence and intensity of cerebral anoxia objectively but also seems to be an important compensatory factor in the maintenance of the normal cerebral function. The circulation and metabolic function in the brain were regulated in two ways by the blood flow regulating mechanism in and outside of the brain and by the compensatory change in CERO_2 of the cerebral tissue itself. The metabolic disturbance of the brain appears to be evoked by the insufficient compensation of CERO_2. Taking into consideration that the results obtained by N_2O method which state that the decrease in cerebral metabolism of the aged people is a secondary phenomenon of the decrease in oxygen supply to the brain, mainly the decrease in CBF, it is supposed that CERO_2 in the aged people should be greater than normal young people. Usually an inverse correlation is assumed between CBF and CERO_2. As the CBF of the aged is mainly due to the asteriosclerosis of the brain, a certain kind of correlation is inferred between CERO_2 and cerebral arteriosclerosis.The present author, to study the correlation between CERO_2 and cerebral arteriosclerosis, has measured CERO_2 in healthy and anemic aged subjects, examined the clinical significance of CERO_2 by comparing to the results obtained by N_2O method, retinal findings, cerebral symptoms and autoptical findings, and obtained the following results.1. The increase in CERO_2 was observed in about 70% of healthy aged subjects. Such frequent cerebral anoxia in healthy older people suggests the possibility of cerebral anoxia and cerebral metabolic disturbance in the aged.2. The assumption that the difference in CERO_2 in healthy aged subjects in caused by the abnormality of cerebral hemodynamics (decrease in CBF and increase in CVR) was confirmed experimentally and by the results obtained by N_2O method.3. The fact that this increase in CVR reflects mainly the attitude of the sclerotic cerebral arteries was examined by the correlation between retinal findings, cerebral symptoms and CERO_2.4. From the above stated results it is inferred that CERO_2 may be applied clinically as a measure of the intensity of cerebral arteriosclerosis.5. However, when anemia, disturbance in pulmonary function, abnormality of cerebral oxygen supply due to other CBF diminishing factors than cerebral arteriosclerosis, or primary metabolic abnormality of the brain is present, some considerations to such abnormal conditions are required.6. In anemic aged people, when the abnormality of the cerebral circulation is intense, anemia acts facilitatory to cerebral anoxia.7. Therefore, in this case, it is supposed that the CBF estimated from CERO_2 takes a value lower than the actual level and that CVR and the intensity of arteriosclerosis take higher levels.8. The intensity of cerebral arteriosclerosis increased in parallel with CERO_2 in the autoptical findings and the hypertensive subjects who increased in CERO_2 has a tendency of cerebral apoplexy. From this results it is inferred that CERO_2 may be applied as a critical signal of cerebral apoplexy too.