Stimulation of L-ornithine and S-adenosyl-L-methionine decarboxylases by beta-(p-chlorophenyl)-gamma-aminobutyric acid in mouse tissues.

Injections of beta-(p--chlorophenyl)-gamma-aminobutyric acid caused a monophasic stimulation of the activity of neural L-ornithine decarboxylase, to reach a maximum of 9-fold compared with the control values 3 h after treatment. Stimulation of hepatic L-ornithine decarboxylase was biphasic, the activity reaching its first peak, 48-fold compared with the control values, similarly at about 3 h after administration, and returning to its initial level by 4 h, and rising to a second peak, about one-third of the magnitude of the first, about 25 h after the injection. The effect in the adrenal gland of the mouse was multiphasic, reaching its maximum, 94-fold enzyme activity compared with the control values, 7--8 h after treatment. There were also marked fluctuations in the activity of S-adenosyl-L-methionine decarboxylase in the tissues examined.