Binding of Ro 5-4864 to brain membranes of rats with and without absence-like phenomena.
Spontaneously occurring spike-wave discharges (SWD) in rats are used as a model for absence epilepsy in humans. In vitro, the binding parameters of 3H-Ro 5-4864, a ligand labelling the peripheral benzodiazepine receptor, were determined for brain membranes of WAG/Rij rats, an inbred strain showing SWD, and for ACI rats, an inbred strain showing no SWD. No difference in the Kd but a small difference in the Bmax values between the strains were found. Recently, other investigators reported a correlation between a decrease in affinity for 3H-Ro 5-4864 and the occurrence of SWD. Our results suggest however that it is doubtful that a change in Kd of the peripheral benzodiazepine receptor is causal in the etio-pathology of the spontaneous absence like phenomena in rats.
van Rijn
C M
CM
Department of Comparative and Physiological Psychology, University of Nijmegen, The Netherlands.
Willems-van Bree
E
E
Rodrigues de Miranda
J F
JF
Vossen
J M
JM
Coenen
A M
AM
D000818:Animals; D001570:Benzodiazepinones / Q000737:chemistry*; D001923:Brain Chemistry; D002462:Cell Membrane / Q000737:chemistry; D002531:Cerebellum / Q000737:chemistry*; D003292:Convulsants / Q000737:chemistry; D004827:Epilepsy / Q000378:metabolism; D051381:Rats; D011912:Rats, Inbred ACI; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000737:chemistry*
D001570:Benzodiazepinones; D003292:Convulsants; D011963:Receptors, GABA-A; C028513:4'-chlorodiazepam