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Receptor redistribution does not accompany terbutaline‐induced down regulation of beta‐adrenergic receptors on human mononuclear leukocytes
Author(s) -
Maisel Alan S,
Motulsky Harvey J
Publication year - 1987
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1038/clpt.1987.115
Subject(s) - terbutaline , receptor , agonist , adrenergic receptor , peripheral blood mononuclear cell , endocrinology , redistribution (election) , medicine , chemistry , pharmacology , biology , in vitro , biochemistry , politics , asthma , political science , law
Mononuclear leukocytes are easily accessible cells for investigating the regulation of β‐adrenergic receptors in humans. We have previously shown that brief incubations with agonists redistribute (? internalize) most of the β‐adrenergic receptors on mononuclear leukocytes away from the cell surface without changing total receptor number. However, negligible redistribution occurred after exercise or an infusion of isoproterenol. The current study was designed to ask whether receptor redistribution occurs over a longer time course after administration of terbutaline, a β 2 ‐adrenergic agonist that is known to cause a decrease in receptor number. Normal volunteers were given terbutaline, 5 mg t.i.d. for 6 days. As expected, the number of β‐adrenergic receptors decreased. However, the remaining receptors were not redistributed. Redistribution also did not occur after 1 or 2 days of terbutaline, at which time down regulation was minimal. We also found that terbutaline did not alter the ability of the receptors to be redistributed or desensitized by a preincubation with isoproterenol. Clinical Pharmacology and Therapeutics (1987) 42, 100–106; doi: 10.1038/clpt.1987.115