title: Binding of [3H]-muscimol, a potent gamma-aminobutyric acid receptor agonist, to membranes of the bovine retina.
abstract: 1 The binding of [3H]-muscimol, a potent gamma-aminobutyric acid (GABA) receptor agonist, to crude membrane preparations of bovine retina was studied, using a filtration method to isolate membrane-bound ligand. 2 Specific binding was found to be saturable and occurred at two binding sites with affinity constants of 4.3 nM and 38.2 nM. 3 Binding was sodium-independent, enhanced by both freezing and Triton X-100 treatment but abolished with sodium laurylsulphate. 4 The binding sites demonstrated a high degree of pharmacological specificity, GABA being a potent displacer of [3H]-muscimol. 5 A higher degree of [3H]-muscimol binding was associated with subcellular fractions enriched with photoreceptor synaptosomes rather than with fractions enriched with conventional synaptosomes.
mesh_terms: D000818:Animals; D002417:Cattle; D066298:In Vitro Techniques; D007700:Kinetics; D008566:Membranes / Q000378:metabolism; D009118:Muscimol / Q000378:metabolism*; D010080:Oxazoles / Q000378:metabolism*; D012160:Retina / Q000378:metabolism* / Q000648:ultrastructure; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D010080:Oxazoles; D009118:Muscimol