Stimulation of L-Ornithine and S-Adenosyl-L-Methionine Decarboxylases by beta-(p-Chlorophenyl)-gamma-aminobutyric Acid in Mouse Tissues.

Abstract

Injections of .beta.-(p-chlorophenyl)-.gamma.-aminobutyric acid caused a monophasic stimulation of the activity of neural L-ornithine decarboxylase [EC 4.1.1.17], 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, at about 3 h after administration, and returning to its initial level by 4 h and rising to a second peak, about 1/3 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 [EC 4.1.1.50] in the tissues examined.