Gamma-aminobutyric acid: a substrate for oxidative metabolism of cerebral cortex

Publisher Website
Google Scholar
Abstract
Oxygen uptake of slices of cat cerebral cortex, which have been preincubated without substrate, is supported by subsequent addition of γ-aminobutyric acid or succinic semialdehyde to an extent comparable to that by glucose or l-glutamic acid. Esterification of phosphate by cat cortex mitochondria is also supported by γ-aminobutyric acid or succinic semialdehyde, which yielded P/O ratios between 2 and 3, similar to ratios obtained with pyruvate or l-glutamic acid. The relevance of these findings to functional activity of the brain is discussed particularly in reference to seizure states, where metabolic abnormalities of glutamic acid and γ-aminobutyric acid occur, and to the physiological roles which have been proposed for γ-aminobutyric acid. It is suggested that cerebral energy metabolism may in part depend upon oxidative metabolism via the glutamic-γ-aminobutyric acid pathway, which could regulate a portion of the available energy and thus affect levels of functional activity.