Open AccessA human embryonic lung fibroblast with a high density of muscarinic acetylcholine receptors
Author(s) -
ANDRÉ Claudine,
MARULLO Stefano,
CONVENTS André,
LÜ Bao Zhang,
GUILLET Jean Gérard,
HOEBEKE Johan,
STROSBERG A. Donny
Publication year - 1988
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1988.tb13804.x
Subject(s) - muscarinic acetylcholine receptor , quinuclidinyl benzilate , muscarinic antagonist , medicine , pirenzepine , endocrinology , agonist , chemistry , muscarinic acetylcholine receptor m5 , muscarinic acetylcholine receptor m4 , muscarinic acetylcholine receptor m2 , receptor , muscarinic agonist , muscarinic acetylcholine receptor m3 , muscarinic acetylcholine receptor m1 , competitive antagonist , biology , biochemistry
Binding studies with the radiolabeled muscarinic antagonists dexetimide, quinuclidinyl benzilate and N ‐methylscopolamine showed that the human embryonic lung fibroblast CCL137 possesses approximately 2 × 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.