THE CENTRAL ACTION OF GAMMA-BUTYROLACTONE AND GAMMA-HYDROXYBUTYRATE

Abstract

The effects of gamma-butyro-lactone (GBL) and gamma-hydroxybutyrate (GHB) on the central nervous system were studied in mice, rats and rabbits. Though both drugs produced depression of spontaneous movements, muscular relaxation and abolition of the righting reflex in these 3 species, they also produced twitching and convulsions in mice and myoclonic jerks and catatonia-like posture in rabbits. The sleeping time induced by pentobarbital Na was prolonged by the combination of GBL in mice, but insignificantly by GHB. The sleeping time was markedly prolonged by the combined administration of ethyl alcohol and GBL or GHB. GBL prevented death caused by electroshock and strychnine in mice, and GHB prevented death induced by electroshock but not by strychnine. Both drugs failed to antagonize death caused by picrotoxin, pentylenetetrazol and semi-carbazide. In the eeg studies in rabbits, intravenous injection of GBL produced slow waves with or without spindle bursts in the cortical eeg and highly desynchronized patterns in the hippocampal eeg. The threshold for the reticular arousal response was slightly elevated by the administration of GBL. Enhancement of fast waves by reticular and septal stimulation was less affected by GBL than production of theta waves. The threshold of the recruiting response was only slightly increased by GBL. Enhancement of the negative phase of the recruiting response was observed with GBL, when the spontaneous eeg showed spike discharges. The dual central actions of GBL are compared with the effects of pentobarbital sodium and pentylenetetrazol.