title: Simultaneous assay of muscarinic and beta-adrenergic receptors using a double isotope technique.
abstract: Muscarinic receptor and beta-adrenergic receptor binding were measured simultaneously in a membrane fraction of bovine tracheal smooth muscle using [3H]-L-quinuclidinyl benzilate and [125I]-(-) iodocyanopindolol. The binding characteristics, affinity and receptor density, obtained in the double receptor assay and in the control experiments were the same within experimental error. Moreover, there appears to be neither a significant influence of an excess of d,1-propranolol on [3H]-L-quinuclidinyl benzilate binding nor a significant influence of an excess of 1-quinuclidinyl benzilate on [125I]-(-)iodocyanopindolol binding. The method is advantageous where both receptors have to be assayed and where limited amounts of biological material, like in biopsy specimen, are available.
mesh_terms: D000818:Animals; D002417:Cattle; D007457:Iodine Radioisotopes; D020120:Iodocyanopindolol; D008722:Methods; D010869:Pindolol / Q000031:analogs & derivatives* / Q000378:metabolism; D011812:Quinuclidines / Q000378:metabolism*; D011813:Quinuclidinyl Benzilate / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000032:analysis* / Q000378:metabolism; D011976:Receptors, Muscarinic / Q000032:analysis* / Q000378:metabolism; D014132:Trachea / Q000032:analysis*; D014316:Tritium
chemical_list: D007457:Iodine Radioisotopes; D011812:Quinuclidines; D011943:Receptors, Adrenergic, beta; D011976:Receptors, Muscarinic; D014316:Tritium; D011813:Quinuclidinyl Benzilate; D020120:Iodocyanopindolol; D010869:Pindolol