title: Binding of (3H)-piretanide to a specific receptor of renal medulla.
abstract: We had previously demonstrated that (3H)-piretanide binds to a receptor located on medullary membranes of canine kidney. Here we show that binding is specific for a particular group of loop diuretics. Sulfonamide diuretics of the benzoic acid family, other substituted sulfonamides, and phenoxy-acetic acid derivates displace (3H)-piretanide from its receptor. Loop diuretics that do not act at the luminal tubular membrane do not displace piretanide, nor do diuretics with a different site and mode of action (thiazides; inhibitors of the Na+/H+ antiporter (amiloride), of Na+K+ ATPase (ouabain), or of carbonic anhydrase (acetazolamide). We demonstrate that no interference occurs between the piretanide receptor and membrane bound receptors of several neurotransmitters.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D004232:Diuretics / Q000494:pharmacology; D004285:Dogs; D007679:Kidney Medulla / Q000378:metabolism*; D008138:Loop of Henle / Q000378:metabolism; D008297:Male; D011955:Receptors, Drug / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013449:Sulfonamides / Q000378:metabolism*
chemical_list: D004232:Diuretics; D011955:Receptors, Drug; D013449:Sulfonamides; C015451:piretanide; D000254:Sodium-Potassium-Exchanging ATPase