Studies on muscarinic acetylcholine receptors from mouse brain: characterization of the interaction with antagonists.
The binding of tritium labeled N-methyl-4-piperidyl benzilate (4-NMPB) and scopolamine to the muscarinic receptor from mouse brain was investigated at 10, 25 and 37 degrees C. Approach to equilibrium experiments indicated that association involved a single population of binding sites. The formation of at least two types of ligand-receptor complexes had however to be assumed to explain the data obtained at 25 and 37 degrees C by equilibrium and dissociation experiments. In contradistinction, at 10 degrees C a single population of ligand-receptor complexes could be detected. The simplest model which fits the experimental findings consists of a fast binding step followed by a slow isomerization process of the receptor-ligand complex.
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001561:Benzilates / Q000378:metabolism; D001667:Binding, Competitive / Q000187:drug effects; D001921:Brain / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D007700:Kinetics; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010276:Parasympatholytics / Q000378:metabolism*; D010277:Parasympathomimetics / Q000008:administration & dosage; D010880:Piperidines / Q000378:metabolism; D011869:Radioligand Assay; D011950:Receptors, Cholinergic / Q000378:metabolism*; D011976:Receptors, Muscarinic / Q000378:metabolism*; D012601:Scopolamine / Q000378:metabolism
D001561:Benzilates; D010276:Parasympatholytics; D010277:Parasympathomimetics; D010880:Piperidines; D011950:Receptors, Cholinergic; D011976:Receptors, Muscarinic; D012601:Scopolamine; D000109:Acetylcholine