The influence of glucose on acetate, alanine and pyruvate metabolism in rat cerebral cortical slices

Abstract

The effect of glucose as co-substrate has been studied on the metabolic fate of [U-14C]alanine [2-14c]acetate and [3-14C]pyruvate in brain cortical slices, using the automatic paper radiochromatographic scanning technique previously described. In comparison to glucose and pyruvate, acetate and alanine were metabolized only to a very small extent by brain cortical tissue. The addition of glucose strongly stimulated the 14CO2 production from acetate, but did not affect 14CO2 production from pyruvate and alanine. The oxygen uptake was stimulated by glucose in presence of all three substances. In addition to CO2 the metabolites formed from pyruvate were aspartate, glutamate, alanine, GABA and lactate. The same metabolites were formed from alanine. The only metabolites, detected with the technique used, formed from acetate, were aspartate and glutamate. The effect of glucose on the metabolites formed from acetate was a marked increase of glutamate, glutamine and GABA and a decrease of aspartate. The effect of glucose on the metabolites formed from alanine was an increase of glutamate, GABA, and lactate, and a decrease of aspartate. The effect of glucose, on the metabolites formed from pyruvate was a very large increase of lactate, and a decrease of all the amino acids formed except glutamine, the formation of which was stimulated.