Characterization of the Solubilized GABA and Benzodiazepine Receptors from Various Regions of Bovine Brain
Article first published online: 12 DEC 2006
Journal of Neurochemistry
Volume 40, Issue 1, pages 209–214, January 1983
How to Cite
Asano, T., Yamada, Y. and Ogasawara, N. (1983), Characterization of the Solubilized GABA and Benzodiazepine Receptors from Various Regions of Bovine Brain. Journal of Neurochemistry, 40: 209–214. doi: 10.1111/j.1471-4159.1983.tb12672.x
- Issue published online: 12 DEC 2006
- Article first published online: 12 DEC 2006
- Received April 26, 1982; revised June 18, 1982; accepted June 28, 1982.
- GABA receptor;
- Benzodiazepine receptor;
- CL 218,872;
- Bovine brain;
- Various regions
Abstract: GABA and benzodiazepine receptors were solubilized from bovine cerebral cortex, cerebellum, and hippocampus and then partially purified by gel filtration and characterized. The apparent molecular weights of all these receptors were determined to be 600,000–650,000 by gel filtration, the sedimentation coefficients being 11.0–11.3 S by sucrose density gradient centrifugation. [3H]Muscimol was bound to two classes of sites in fractions from all three regions, and [3H]flunitrazepam bound to one class of sites. A comparison of the ratios of Bmax for fiunitrazepam binding to Bmax for muscimol binding revealed that the fractions from the hippocampus exhibited a much higher ratio of benzodiazepine binding sites than were detected in fractions from the cortex and cerebellum. GABA agonist and antagonist inhibited [3H]muscimol binding to the fractions from these three regions, at similar concentrations. Benzodiazepine agonists and antagonists also inhibited [3H]flunitrazepam binding in these three fractions, with similar potency. CL 218,872, however, inhibited [3H]flunitrazepam binding in the cerebellar fraction with the lowest IC50 value and that in the hippocampal fraction with the highest IC50 value. Hill coefficients for CL 218,872 inhibition were 0.98, 0.64, and 0.58 for cerebellum, cortex, and hippocampus, respectively.