title: Papaverine inhibits binding of [3H]-prazosin and [3H]-yohimbine to rat renal cortical membranes.
abstract: We examined the effects of papaverine on specific [3H]-prazosin and [3H]-yohimbine bindings to rat renal cortical membranes and compared these effects with those of verapamil. Papaverine inhibited both ligand bindings with KI values of 4.2 +/- 1.7 microM and 48.4 +/- 8.7 microM (N = 5) in the inhibition of [3H]-prazosin and [3H]-yohimbine bindings, respectively. In contrast with verapamil, which competitively inhibited both ligand bindings, papaverine inhibited them in a different manner. Although the affinities of these ligand binding sites for papaverine are low, alpha-receptor blockade is a possible mechanism of action of this compound.
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D066298:In Vitro Techniques; D007672:Kidney Cortex / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D010208:Papaverine / Q000494:pharmacology*; D011224:Prazosin / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*; D014316:Tritium; D014700:Verapamil / Q000494:pharmacology; D015016:Yohimbine / Q000378:metabolism*
chemical_list: D011942:Receptors, Adrenergic, alpha; D014316:Tritium; D015016:Yohimbine; D014700:Verapamil; D010208:Papaverine; D009638:Norepinephrine; D011224:Prazosin