| pubmed-article:6151628 | pubmed:abstractText | Central benzodiazepine (BZ) receptors were looked for in the spinal cord, cerebral cortex and cerebellum of the cat. Both [3H]Ro 15-1788 and [3H]flunitrazepam bound to benzodiazepine receptors with apparent dissociation constants (KD) in the nanomolar range and Hill coefficients near unity. The concentration of binding sites was much greater (10-40 times,depending on the ligand used) in the cortex and cerebellum than in the spinal cord. gamma-Aminobutyric acid (GABA) significantly reduced the KD value of the binding of tritiated flunitrazepam in all three areas of the central nervous system (CNS). The displacement of [3H]Ro 15-1788 by different benzodiazepine ligands indicates a relative prevalence of BZ1 (high affinity for beta-carboline esters and the triazolopyridazine, CL 218 872) in the cerebellum, a predominance of BZ2 (low affinity for the same agents) in the spinal cord and a mixture of both types in the cortex. The possibility that there is regional heterogeneity of receptors for benzodiazepines in CNS of the cat is discussed. | lld:pubmed |
