Regulation of renal Na(+),K(+)-ATPase and ouabain-sensitive H(+),K(+)-ATPase by the cyclic AMP-protein kinase A signal transduction pathway

Acta Biochim Pol. 2003;50(1):103-14.

Abstract

We investigated the effect of the cyclic AMP-protein kinase A (PKA) signalling pathway on renal Na(+),K(+)-ATPase and ouabain-sensitive H(+),K(+)-ATPase. Male Wistar rats were anaesthetized and catheter was inserted through the femoral artery into the abdominal aorta proximally to the renal arteries for infusion of the investigated substances. Na(+),K(+)-ATPase activity was measured in the presence of Sch 28080 to block ouabain-sensitive H(+),K(+)-ATPase and improve specificity of the assay. Dibutyryl-cyclic AMP (db-cAMP) administered at a dose of 10(-7) mol/kg per min and 10(-6) mol/kg per min increased Na(+),K(+)-ATPase activity in the renal cortex by 34% and 42%, respectively, and decreased it in the renal medulla by 30% and 44%, respectively. db-cAMP infused at 10(-6) mol/kg per min increased the activity of cortical ouabain-sensitive H(+),K(+)-ATPase by 33%, and medullary ouabain-sensitive H(+),K(+)-ATPase by 30%. All the effects of db-cAMP were abolished by a specific inhibitor of protein kinase A, KT 5720. The stimulatory effect on ouabain-sensitive H(+),K(+)-ATPase and on cortical Na(+),K(+)-ATPase was also abolished by brefeldin A which inhibits the insertion of proteins into the plasma membranes, whereas the inhibitory effect on medullary Na(+),K(+)-ATPase was partially attenuated by 17-octadecynoic acid, an inhibitor of cytochrome p450-dependent arachidonate metabolism. We conclude that the cAMP-PKA pathway stimulates Na(+),K(+)-ATPase in the renal cortex as well as ouabain-sensitive H(+),K(+)-ATPase in the cortex and medulla by a mechanism requiring insertion of proteins into the plasma membrane. In contrast, medullary Na(+),K(+)-ATPase is inhibited by cAMP through a mechanism involving cytochrome p450-dependent arachidonate metabolites.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brefeldin A / pharmacology
  • Bucladesine / pharmacology
  • Cell Membrane / enzymology
  • Cyclic AMP-Dependent Protein Kinases / antagonists & inhibitors
  • Cyclic AMP-Dependent Protein Kinases / metabolism*
  • Enzyme Inhibitors / pharmacology
  • Fatty Acids, Unsaturated / pharmacology
  • H(+)-K(+)-Exchanging ATPase / metabolism*
  • Imidazoles / pharmacology
  • Kidney / enzymology*
  • Kidney Cortex / enzymology
  • Kidney Medulla / enzymology
  • Male
  • Ouabain / pharmacology*
  • Rats
  • Rats, Wistar
  • Signal Transduction
  • Sodium-Potassium-Exchanging ATPase / metabolism*

Substances

  • Enzyme Inhibitors
  • Fatty Acids, Unsaturated
  • Imidazoles
  • Sch 28080
  • Brefeldin A
  • 17-octadecynoic acid
  • Ouabain
  • Bucladesine
  • Cyclic AMP-Dependent Protein Kinases
  • H(+)-K(+)-Exchanging ATPase
  • Sodium-Potassium-Exchanging ATPase