Identification and pharmacological properties of binding sites for the atypical thiazide diuretic, indapamide

Eur J Pharmacol. 1990 Jul 17;182(3):503-8. doi: 10.1016/0014-2999(90)90048-b.

Abstract

[3H]Indapamide bound to a single class of binding sites in pig renal cortex membranes with a dissociation constant Kd = 35 +/- 13 nM and a binding site density Bmax = 40 +/- 9 pmol/mg of protein. [3H]Indapamide binding was inhibited by the carbonic anhydrase inhibitor, acetazolamide, and by thiazide diuretics with the following rank order of potency: chlorothiazide greater than hydrochlorothiazide approximately metolazone greater than hydroflumethiazide. The effect of the latter drugs to inhibit [3H]indapamide binding was not related to their activity as thiazide diuretics, but was significantly correlated with their inhibitory effect on carbonic anhydrase II. These results suggest that the major renal binding site of [3H]indapamide is a membrane form of carbonic anhydrase. Inhibition of carbonic anhydrase may play a role in the antihypertensive effect of indapamide.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites
  • Carbonic Anhydrase Inhibitors / pharmacology
  • In Vitro Techniques
  • Indapamide / metabolism*
  • Indapamide / pharmacology
  • Kidney Cortex / drug effects
  • Kidney Cortex / metabolism*
  • Kinetics
  • Swine

Substances

  • Carbonic Anhydrase Inhibitors
  • Indapamide