SUBSTANCES WHICH SUPPORT RESPIRATION AND METABOLIC RESPONSE TO ELECTRICAL IMPULSES IN HUMAN CEREBRAL TISSUES

Abstract

Forty specimens of human cerebral tissues, obtained during prefrontal and temporal lobectomy, showed a mean respiratory rate in phosphate-buffered saline of 55 [mu] moles O2/g. fresh tissue/hr. Variation was large but rate change small during first two hours metabolism. Applied electrical discharges increased the rate to 110 [mu] moles O2/g./hr. which is closer to the probable rate in situ. Aerobic accumulation of lactic acid (glucose substrate) was 25 [mu] mole/g. fresh wt./hr. and could be doubled by applied electrical impulses. Phosphate saline without glucose substrate had a low initial respiratory rate which fell after 30 minutes and failed to respond to electrical responses. Fumarate as substrate was without effect on the lower rate, its fall and with applied impulses. Succinate maintained respiration without susceptibility to impulses. Citrate was less stable but lactate and pyruvate maintained both the respiratory rate and response to impulses. Human tissue in glutamic acid differed from guinea pig and monkey tissues in that it maintained both respiratory rate and response to impulses.