Antagonism of the spinal action of diazepam by semicarbazide

In spinal unanaesthetized cats, pretreatment with semicarbazide (200 mg/kg) 2-4.5 h prior to the administration of diazepam (1-4 mg/kg) completely blocked the enhancement of the segmental dorsal root reflex by the latter compound. Pyridoxine hydrochloride (200 mg/kg), given 3.5 h after semicarbazide, restored the spinal effect of diazepam administered 1 h later. The possibility of a link between diazepam and spinal gamma-aminobutyric acid is suggested and discussed.