Differential effects of GABA on peripheral and central type benzodiazepine binding sites in brain.
The binding of the clinically inactive benzodiazepine [3H]RO-5-4864 to brain membranes was investigated. The peripheral type benzodiazepine binding site was demonstrated in brain with an apparent Kd of 1.6 nM and a Bmax of 20 fmol/mg protein. Monophasic Scatchard plots indicate a homogenous population of a high affinity sites. The major inhibitory transmitter GABA, has no effect on [3H]RO-5-4864 binding to extensively wash brain membranes. The peripheral type benzodiazepine binding site found in brain is therefore not modulated GABA.
D000818:Animals; D001570:Benzodiazepinones / Q000378:metabolism*; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D003975:Diazepam / Q000378:metabolism; D051381:Rats; D011955:Receptors, Drug / Q000187:drug effects* / Q000378:metabolism; D011963:Receptors, GABA-A; D013570:Synaptic Membranes / Q000187:drug effects / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D001570:Benzodiazepinones; D011955:Receptors, Drug; D011963:Receptors, GABA-A; C028513:4'-chlorodiazepam; D005680:gamma-Aminobutyric Acid; D003975:Diazepam