Glucose, Glutamate and Succinate Oxidation in Brain

Abstract

THERE have, for some time, been difficulties in interpreting the role of glutamate in brain metabolism and its relation to glucose oxidation^1–4. Weil-Malherbe² has adduced evidence to show that, in brain, summation of oxidations occurs if glucose and glutamate are used together as substrate. Krebs and Eggleston⁵ have shown that the diffusion of potassium from brain cells in vitro is only fully prevented if both glucose and glutamate are present in the medium. On the other hand, Furchgott and Shorr6 have found that at low oxygen tensions the addition of succinate to brain depresses the normal metabolic activities of the tissue, despite the fact that an increase in oxygen uptake occurs. Our investigations have given rise to certain considerations which seem relevant to this problem.