title: Dose-dependent down-regulation of beta-adrenoceptors by isoproterenol in rat C6 glioma cells.
abstract: Nano- and micromolar isoproterenol concentrations were compared by studying cyclic AMP, beta-adrenoceptor density and beta 1-adrenoceptor mRNA in rat C6 glioma cells. 1 microM isoproterenol significantly changed all parameters at 15-30 min. The beta 1-antagonist metoprolol attenuated the response. No effects of nanomolar isoproterenol on these early changes were observed, although the density of beta-adrenoceptors was significantly reduced beginning at 12 h. The results indicate a different process for beta-adrenoceptor desensitization in C6 cells following physiologically low agonist concentrations.
authors.affiliation: Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, TN 37232.
authors.forename: P R
authors.initials: PR
authors.lastname: Bieck
authors.forename: D M
authors.initials: DM
authors.lastname: Duhl
authors.forename: A
authors.initials: A
authors.lastname: Eiring
authors.forename: D D
authors.initials: DD
authors.lastname: Gillespie
authors.forename: D H
authors.initials: DH
authors.lastname: Manier
authors.forename: F
authors.initials: F
authors.lastname: Sulser
mesh_terms: D000818:Animals; D000242:Cyclic AMP / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D005910:Glioma / Q000378:metabolism*; D007545:Isoproterenol / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011943:Receptors, Adrenergic, beta / Q000187:drug effects*; D014407:Tumor Cells, Cultured
chemical_list: D012333:RNA, Messenger; D011943:Receptors, Adrenergic, beta; D000242:Cyclic AMP; D007545:Isoproterenol