Modulatory effect of some steroid hormones, their glucuronides and ouabain-like compounds on Cavia cobaya kidney Na+,K(+)-ATPase activity

Gen Pharmacol. 1990;21(4):435-42. doi: 10.1016/0306-3623(90)90694-h.

Abstract

1. Ouabain-like compounds (approx. mol. wt 700, 2,000 and 4,000 Da) were purified from plasma of essential hypertensive patients. 2. Dose-response experiments performed with (a) steroid hormones, (b) their glucuronides and (c) ouabain-like compounds, emphasize a modulatory effect [activation of the Na,K-ATPase at very low concentrations of ligand, inhibition at higher levels; apparent Ki: (a) between 1 and 0.5 mM; (b) between 1 and 0.5 microM; and (c) between 10 and 1 nM; maximum enhancement of the enzymatic activity: (a) +20%; (b) +45%; and (c) +100%]. 3. Displacement experiments of [3H]ouabain evidence a high competition of the ligands towards the cardioglycoside. The relative I50s are: (a) between 1 and 0.5 mM; (b) between 10 and 1 microM; and (c) between 10 and 0.01 nM.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding, Competitive / drug effects
  • Dose-Response Relationship, Drug
  • Glucuronates / pharmacology
  • Guinea Pigs
  • Hormones / physiology*
  • Hypertension / blood
  • In Vitro Techniques
  • Kidney / drug effects
  • Kidney / enzymology*
  • Ligands
  • Ouabain / analogs & derivatives
  • Ouabain / pharmacology*
  • Proteins / metabolism
  • Sodium-Potassium-Exchanging ATPase / analysis
  • Sodium-Potassium-Exchanging ATPase / isolation & purification
  • Sodium-Potassium-Exchanging ATPase / metabolism*
  • Steroids / physiology*

Substances

  • Glucuronates
  • Hormones
  • Ligands
  • Proteins
  • Steroids
  • Ouabain
  • Sodium-Potassium-Exchanging ATPase