title: Desensitization of muscarinic receptors.
abstract: When Chinese hamster ovary cells transfected with the gene for M(3)-muscarinic receptors were stimulated with carbachol continuously for 30 min, the response at the end of the stimulation period was about 20% of the early response (2-3 min after the start of the stimulation). Long-term treatment of the cells with phorbol ester abolished the response completely while desensitization was significantly reduced upon pre-treatment of the cells with GF109203X, antisense oligonucleotide against the alpha-isoform of protein kinase C and wortmannin. We conclude that in the Chinese hamster ovary expression system, desensitization of M(3)-muscarinic receptors is dependent on a fast feedback loop including the alpha-isoform of protein kinase C.
authors.affiliation: Heymans Institute for Pharmacology, Ghent University Hospital, De Pintelaan 185, B-9000 Ghent, Belgium. norbert.fraeyman@UGent.be
authors.forename: N
authors.initials: N
authors.lastname: Fraeyman
authors.forename: J
authors.initials: J
authors.lastname: van Emmelo
authors.forename: R H
authors.initials: RH
authors.lastname: Paulssen
authors.forename: K
authors.initials: K
authors.lastname: Vermis
mesh_terms: D000818:Animals; D016466:CHO Cells; D002217:Carbachol / Q000494:pharmacology*; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D018721:Muscarinic Agonists / Q000494:pharmacology*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D011976:Receptors, Muscarinic / Q000378:metabolism*; D013395:Sucrose / Q000378:metabolism
chemical_list: D018721:Muscarinic Agonists; D011976:Receptors, Muscarinic; D013395:Sucrose; D002217:Carbachol; D011493:Protein Kinase C