Über den Brenztraubensäurestoffwechsel im Gehirn

Abstract

Mixtures of 100 g. of minced brain (beef, guinea pig, rat), 250 cc. 0.025 M bicarbonate buffer and 495 mg. Na pyruvate were incubated aerobically and anaerobically for 2 hrs. at 37[degree], followed by detn. of pyruvic, lactic, succinic, a-keto-glutaric, fumaric, malic, oxalacetic, citric, acetic, formic and glutamic acids and alanine. More pyruvic acid disappeared in the presence of O than under anaerobic conditions. In both cases, the amts. of lactic and a-ketoglutaric formed were equivalent, respectively, to about 43 and 17% of the pyruvic acid metabolized. Succinic acid was present in much smaller amts. if at all and no significant amts. of fumaric, malic, formic, and oxalacetic acids were formed. Citric acid was not formed in the absence of O, but small amts. were detected in the presence of O, especially if C4-dicarboxylic acids were present. In the anaerobic expts. 17%, and in the aerobic expts. 6%, of the metabolized pyruvic acid was recovered as acetic acid, and the amts. of alanine obtained were equivalent to 18% and to 16%, respectively, of the pyruvic acid. Possibly the animal organism can convert pyruvic acid directly into dicarboxylic acids.