title: Radioreceptor assay for oxyphenonium.
abstract: The development of a radioreceptor assay for the quaternary anticholinergic drug, oxyphenonium, in plasma is reported. It is based on competition between this drug and 3H-dexetimide for binding to muscarinic receptors. After ion pair extraction and reextraction, the drug can be determined in plasma at concentrations down to a value of 100 pg/ml. This permits pharmacokinetic studies to be made after inhalation of oxyphenonium.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002417:Cattle; D003909:Dexetimide / Q000378:metabolism; D010115:Oxyphenonium / Q000378:metabolism*; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D011869:Radioligand Assay / Q000379:methods*
chemical_list: D000644:Quaternary Ammonium Compounds; D003909:Dexetimide; C027435:tetrapentylammonium; D010115:Oxyphenonium