Article date: 1988/1/1
PubMed ID: 2845114
Journal name: Journal of neuroscience research (ISSN: 0360-4012)
The effect of several ligands and Ca2+ ions on [3H]GABA binding to bovine adrenal medulla membranes was investigated. Without any blockade, the [3H]GABA binding showed two components, one of low affinity (Kd = 139 +/- 22 nM and Bmax = 3.2 +/- 0.4 pmol/mg protein) and the other of high affinity (Kd = 41 +/- 6 nM and Bmax = 0.35 +/- 0.26 pmol/mg protein). Muscimol specifically blocked low-affinity sites, and (-)baclofen blocked high-affinity components. Ca2+ ions were strictly necessary for maximum binding to high-affinity sites, whereas they did not significantly affect sites of the lower affinity. These results show that the bovine adrenal medulla has a GABAA receptor population of low affinity together with a GABAB receptor of high affinity.
Author List: Castro E, Oset-Gasque M J, Cañadas S, Gimenez G, González M P
Publication Types: Journal Article
Substances mentioned in the article: Receptors, GABA-A; Muscimol; gamma-Aminobutyric Acid; Baclofen; Calcium;
Mesh terms: Adrenal Medulla/metabolism; Animals; Baclofen/pharmacology; Binding Sites; Calcium/pharmacology; Cattle; Cell Membrane/metabolism; In Vitro Techniques; Kinetics; Muscimol/pharmacology; Receptors, GABA-A/drug effects; gamma-Aminobutyric Acid/metabolism;