Preliminary characterization of the acetylcholine receptor in human erythrocytes.
The response of human erythrocytes to cholinergic ligands was studied with an electron spin resonance assay. The membrane response to carbamyl choline was found to be antagonized by atropine and, in the absence of calcium, by tetrodotoxin. Experiments with resealed ghosts showed that the membrane response to carbamyl choline required ATP and calcium. Reductive alkylation of intact cells eliminated the cholinergic response, but the presence of saturating amounts of carbamyl choline protected the putative receptor against inactivation. Affinity labeling was used to demonstrate an apparent molecular weight of 41,000 for the carbamyl choline-binding species. A lipid vesicle extraction technique was used to induce a specific cation permeability defect in intact cells. Preliminary investigation of this phenomenon is described.
D000109:Acetylcholine / Q000097:blood*; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000328:Adult; D001665:Binding Sites; D001798:Blood Proteins / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology; D002217:Carbachol / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D004578:Electron Spin Resonance Spectroscopy; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D006461:Hemolysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010713:Phosphatidylcholines / Q000097:blood; D011485:Protein Binding; D011487:Protein Conformation; D011950:Receptors, Cholinergic / Q000187:drug effects; D012964:Sodium / Q000097:blood
D001798:Blood Proteins; D010713:Phosphatidylcholines; D011950:Receptors, Cholinergic; D000255:Adenosine Triphosphate; D002217:Carbachol; D012964:Sodium; D000109:Acetylcholine; D002118:Calcium