Benzodiazepine anticonvulsants accelerate and beta-carboline convulsants decelerate the kinetics of [35S]TBPS binding at the chloride ionophore.

The effect of flunitrazepam and DMCM was examined on the kinetics of [35S]t-butylbicyclophosphorothionate (TBPS) binding. The enhancing effect of flunitrazepam and the decreasing effect of DMCM on TBPS binding was due to non-equilibrium conditions. The anticonvulsant benzodiazepine increased both the association and dissociation rate constants. The convulsant beta-carboline had the opposite effect. Benzodiazepine receptor ligands might affect the convulsant TBPS sites parallel with opening/closing of the chloride ionophores.