title: A human embryonic lung fibroblast with a high density of muscarinic acetylcholine receptors.
abstract: Binding studies with the radiolabeled muscarinic antagonists dexetimide, quinuclidinyl benzilate and N-methylscopolamine showed that the human embryonic lung fibroblast CCL137 possesses approximately 2 X 10(5) muscarinic receptors/cell, i.e. 2.1 pmol/mg membrane protein. These receptors showed a marked stereoselectivity towards dexetimide and levetimide and only low affinity for another antagonist, pirenzepine. The muscarinic agonist carbamylcholine inhibited forskolin-stimulated adenylate cyclase and induced phosphatidylinositide turnover in the intact cells. Both effects were inhibited by the muscarinic antagonist atropine. Affinity labeling with tritiated propylbenzylcholine mustard revealed a protein of 72 kDa. Finally, down-regulation of the membrane receptors following prolonged treatment with the agonist carbamylcholine was assessed by means of the hydrophilic antagonist N-methylscopolamine.
authors.affiliation: Laboratoire de Biochimie Cellulaire, Collège de France, Paris.
authors.forename: C
authors.initials: C
authors.lastname: André
authors.forename: S
authors.initials: S
authors.lastname: Marullo
authors.forename: A
authors.initials: A
authors.lastname: Convents
authors.forename: B Z
authors.initials: BZ
authors.lastname: Lü
authors.forename: J G
authors.initials: JG
authors.lastname: Guillet
authors.forename: J
authors.initials: J
authors.lastname: Hoebeke
authors.forename: D A
authors.initials: DA
authors.lastname: Strosberg
mesh_terms: D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D003909:Dexetimide / Q000378:metabolism; D005347:Fibroblasts; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism; D008168:Lung; D019832:N-Methylscopolamine; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D011976:Receptors, Muscarinic / Q000378:metabolism*; D012602:Scopolamine Derivatives / Q000378:metabolism
chemical_list: D007295:Inositol Phosphates; D011976:Receptors, Muscarinic; D012602:Scopolamine Derivatives; D003909:Dexetimide; D011813:Quinuclidinyl Benzilate; D000242:Cyclic AMP; D006152:Cyclic GMP; D019832:N-Methylscopolamine