Barbiturate enhancement of [(3)H]flunitrazepam binding to purified benzodiazepine/gaba receptor from rat brain.
The presence of an ionophore site was demonstrated on the benzodiazepine/GABA receptor complex purified from rat brain. [(3)H]Flunitrazepam binding to the purified receptor was enhanced by Clions and barbiturate, compounds that interact with the ionophore site. The enhancement was concentration dependent and antagonized by the convulsant drug picrotoxinin. The site was directly labelled by [(3)S]t-butylbicyclophosphorothionate, a blocking agent of the GABA-controlled ionophore channel. The binding was specific and saturable and showed a dissociation constant of 52 nM.
Martini
C
C
Istituto Policattedra di Discipline Biologiche, Universitá di Pisa, Pisa, Italy.
Bertolini
M
M
Giannaccini
G
G
Lucacchini
A
A