Fate of uniformly labelled ¹⁴ C glucose in brain slices

Abstract

The fate of uniformly labelled 14 C glucose in rat-brain slices has been followed by a quantitative application of the radio paper-chromatography technique. After 60 min incubation with brain tissue approximately 60% of the glucose disappearing from the medium was accounted for as lactic acid, about 20% as CO 2 and most of the remainder as free amino-acids. Of the total glucose metabolized approximately 9% was converted into glutamic acid, 1.5% alanine, 3% γ -amino-butyric acid and 2.4% aspartic acid. Glutamic acid was the first of the amino-acids to be formed from glucose, and was detectable after 3 min incubation of brain tissue with 14 C glucose. Insulin had no effect on glucose metabolism in brain slices. Under anaerobic conditions the total glucose metabolized by brain slices was only about 10% of that found under aerobic conditions; of the total glucose disappearing from the medium anaerobically about 80% was accounted for as lactic acid and the remainder as free unchanged glucose in the tissue cells.

Effects of Dieldrin, Picrotoxin and Telodrin on the Metabolism of Ammonia in Brain

“…to account for respiration from glucose in vitro at 2-0 ,moles of oxygen/g./min. (BeloffChain, Catanzaro, Chain, Masi & Pocchiari, 1955) are consistent with the later deceleration of glutamine synthesis that has been described (Hathway & Mallinson, 1964). The decrease in glutamic acid concentration was small (0.52 ,umole/g.)…”

Placental Transfer of Amino Acids in the Rat I. L-Glutamic Acid and L-Glutamine

“…3 The number in parenthesis designates the number o f animals used. For prenatal experiments this number refers to pregnant animals; from each 3 fetuses were used.…”

“…Amino acids are known to be synthetized from glucose fragments in the immature brain [3]. More specifically, in adult cats, glutamic acid was shown to be made in the brain and not to originate from blood [21].…”

Viability of some metabolic processes in the isolated toad brain adapted to two osmotic environments

“…By contrast, slices of mature mammalian CNS tissues invariably swell (accumulate HiO) in iso-osmotic media (Elliott, 1969), and there is a net protein breakdown (Neidle and Kandera, 1972). Furthermore, lactate appears to be the principal product of glucose metabolism in mammalian cerebral tissue slices (Beloff-Chain, Catanzaro, Chain, Masi, and Pocchiari, 1954;Chain, Rose, Masi and Pocchiari, 1969).…”