title: A muscarinic acetylcholine receptor, present in the epithelial cell line from Chironomus tentans.
abstract: A muscarinic cholinergic receptor (mAchR) is present in the non-neuronal epithelial cell line from Chironomus tentans. Scatchard plot analysis (KD = 1.4 nM) using the non-selective antagonist quinuclidinylbenzilate (QNB), as well as kinetic data (KD = 1.7 nM), reveals one class of high affinity binding sites. About 2000 binding sites/cell are present. The receptor concentration (54.5 +/- 7.5 fmol/mg protein) is comparable to the values reported from insect brain. The receptor interacts only with muscarinic ligands; nicotinergic acetylcholine receptors are not present. Binding properties are not comparable to any of the muscarinic subtypes known from vertebrate tissues. The rank order of competition of radiolabelled QNB is: QNB > atropine > PrBCM > oxotremorine, pirenzepine > methoctramine. The competition curve obtained with carbamylcholine is shifted to higher ligand concentrations in the presence of Gpp(NH)p and to lower carbamylcholine concentrations by 1 mM NEM. With antibodies against muscarinic receptor from calf brain one band with a molecular weight of about 80 kDa is detected on Western blots. The moulting hormone 20-OH-ecdysone transiently increases the concentration of muscarinic receptor.
authors.affiliation: Lehrstuhl für Hormon- und Entwicklungsphysiologie, Heinrich-Heine-Universität Düsseldorf, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Wegener
authors.forename: M
authors.initials: M
authors.lastname: Spindler-Barth
authors.forename: K D
authors.initials: KD
authors.lastname: Spindler
mesh_terms: D000818:Animals; D001285:Atropine / Q000378:metabolism; D001665:Binding Sites; D001667:Binding, Competitive; D015153:Blotting, Western; D002217:Carbachol / Q000378:metabolism; D002460:Cell Line; D002683:Chironomidae; D004441:Ecdysterone / Q000502:physiology*; D004848:Epithelium / Q000378:metabolism; D005033:Ethylmaleimide / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D007700:Kinetics; D010095:Oxotremorine / Q000378:metabolism; D010890:Pirenzepine / Q000378:metabolism; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000378:metabolism*
chemical_list: D011950:Receptors, Cholinergic; D006165:Guanylyl Imidodiphosphate; D010890:Pirenzepine; D004441:Ecdysterone; D010095:Oxotremorine; D011813:Quinuclidinyl Benzilate; D001285:Atropine; D002217:Carbachol; D005033:Ethylmaleimide