title: Determination of the desensitization of beta-adrenergic receptors by [3H]CGP-12177.
abstract: Isoprenaline treatment of C6-glioma cells induced a fast decrease in the number of beta-adrenergic receptors as determined by binding of [3H]CGP-12177, which paralleled the decrease in the hormonally stimulated adenylate cyclase activity. The total number of receptors, as determined by binding of (-)-[3H]dihydroalprenolol, did not decrease. Separation of the beta-adrenergic receptors on a sucrose density gradient showed that the decrease in the number of receptors detectable with CGP-12177 was due to a movement of the receptors from the plasma membrane to a vesicular cell compartment. By using both (-)-[3H]dihydroalprenolol and [3H]CGP-12177 it is thus possible to differentiate between the total number of receptors and those present at the plasma membrane in an unfractionated cell lysate.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000319:Adrenergic beta-Antagonists / Q000378:metabolism*; D001665:Binding Sites; D001667:Binding, Competitive; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D004082:Dihydroalprenolol / Q000378:metabolism; D005910:Glioma / Q000378:metabolism; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology*; D011412:Propanolamines / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects*
chemical_list: D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; D011943:Receptors, Adrenergic, beta; D004082:Dihydroalprenolol; D000262:Adenylyl Cyclases; D007545:Isoproterenol; C033394:CGP 12177