Regulatory interrelations between GABA and polyamines. I. Brain GABA levels and polyamine metabolism.

Elevation of brain GABA levels by GABA-T inhibition is accompanied by a decrease of S-adenosylmethionine decarboxylase activity. This is followed by an increase of ornithine decarboxylase activity and a severalfold increase of brain putrescine levels. Spermidine and spermine levels are not significantly affected under these conditions. These unexpected findings support a regulatory interaction between GABA and polyamine metabolism.