title: High affinity binding of a potassium channel agonist to intact rat insulinoma cells.
abstract: The specific binding of a novel tritiated K+ channel opener, [3H]BAY X 9228, has been characterized in a rat insulinoma (RINm5F) cell line. The KD was 2.1 nM and Bmax 50 fmol/mg total protein as determined by saturation analysis. The high affinity binding to intact cells was inhibited by pinacidil and by a series of BAY X 9228 analogs with an activity sequence correlating well with that for producing glyburide-reversible relaxation of partially depolarized rat aorta. This represents the first report of the specific binding of a K+ channel opener to cultured cells.
authors.affiliation: Institute for Preclinical Pharmacology, Miles Inc., West Haven, CT 06516.
authors.forename: F J
authors.initials: FJ
authors.lastname: Hoffman
authors.forename: J B
authors.initials: JB
authors.lastname: Lenfers
authors.forename: E
authors.initials: E
authors.lastname: Niemers
authors.forename: U
authors.initials: U
authors.lastname: Pleiss
authors.forename: A
authors.initials: A
authors.lastname: Scriabine
authors.forename: R A
authors.initials: RA
authors.lastname: Janis
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology; D001665:Binding Sites; D001667:Binding, Competitive; D005905:Glyburide / Q000378:metabolism / Q000494:pharmacology; D006146:Guanidines / Q000494:pharmacology; D007340:Insulinoma / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D009574:Nitro Compounds / Q000378:metabolism* / Q000494:pharmacology; D010671:Phenylurea Compounds / Q000378:metabolism* / Q000494:pharmacology; D020110:Pinacidil; D015221:Potassium Channels / Q000502:physiology*; D051381:Rats; D014407:Tumor Cells, Cultured; D014664:Vasodilation / Q000187:drug effects
chemical_list: D006146:Guanidines; D009574:Nitro Compounds; D010671:Phenylurea Compounds; D015221:Potassium Channels; C079478:Bay Q 3111; D020110:Pinacidil; D005905:Glyburide