[Effect of gamma-aminobutyric acid analogs on the brain GABA-ergic system participating in cardiovascular regulation].

In pentobarbital-anesthetized cats GABA methylester (MEG) and beta-phenyl-GABA methylester (MEF) administered intravenously in doses of 1/100, 1/30, 1/10 of LD50 and injected intracerebroventricularly in doses of 0.1 and 0.5 mg produce hypotension, These effects are significantly suppressed by picrotoxin. These compounds administered intracerebroventricularly in larger doses increase blood pressure, heart rate and sympathetic impulse outflow. Picrotoxin does not decrease these effects. MEG and MEF inhibit the GABA-transaminase activity of mouse brain in vivo. MEF increases and MEG decreases GABA concentration in the whole mouse brain.