Antagonism of some central effects of d-tubocurarine by gamma-aminobutyric acid.

d-Tubocurarine (dtc) administered intracerebroventricularly (icv) to rats produced seizures. Gamma-aminobutyric acid (GABA) administered icv or hydroxylamine administered intraperitoneally (ip) protected the rats from dtc-induced seizures. GABA administered (ip) was ineffective. Local application of dtc to the spinal cord in decerebrate dogs produced facilitation of the scratch reflex. Application of GABA to the spinal cord inhibition the scratch reflex. It is thus concluded that the excitatory effects of dtc on the CNS may be through inhibition of naturally occurring inhibitory substances such as GABA or a closely related compound.