title: Clotrimazole and efaroxan inhibit red cell Gardos channel independently of imidazoline I1 and I2 binding sites.
abstract: In the present report, we investigated the potential involvement of imidazoline I1 and I2 binding sites in the inhibition of the Ca(2+)-activated K+ channel (Gardos channel) by clotrimazole in human red cells. Ca(2+)-activated 86Rb influx was inhibited by clotrimazole and efaroxan but not by the imidazoline binding site ligands clonidine, moxonidine, cirazoline and idazoxan (100 microM). Binding studies with [3H]idazoxan and [3H]p-aminoclonidine did not reveal the expression of I1 and I2 binding sites in erythrocytes. These data indicate that the effects of clotrimazole and efaroxan on the erythrocyte Ca(2+)-activated K+ channel may be mediated by a 'non-I1/non-I2' binding site.
authors.affiliation: INSERM U388, Institut Louis Bugnard, CHU Rangueil, Toulouse, France.
authors.forename: I
authors.initials: I
authors.lastname: Coupry
authors.forename: C C
authors.initials: CC
authors.lastname: Armsby
authors.forename: S L
authors.initials: SL
authors.lastname: Alper
authors.forename: C
authors.initials: C
authors.lastname: Brugnara
authors.forename: A
authors.initials: A
authors.lastname: Parini
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D001572:Benzofurans / Q000494:pharmacology*; D001665:Binding Sites; D002118:Calcium / Q000494:pharmacology; D003022:Clotrimazole / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007093:Imidazoles / Q000378:metabolism* / Q000494:pharmacology*; D015221:Potassium Channels / Q000187:drug effects*
chemical_list: D000317:Adrenergic alpha-Antagonists; D001572:Benzofurans; D007093:Imidazoles; D015221:Potassium Channels; C062597:efaroxan; D003022:Clotrimazole; D002118:Calcium