Regulation of Endothelial Na+-K+-ATPase Activity by cAMP

• Published in: Biochemical and biophysical research communications 1998-01, Vol.242 (1), p.93-97
• Main Authors: Gruwel, Marco L.H., Čulić, Ognjen, Muhs, Andreas, Williams, John P., Schrader, Jürgen
• Format: Article
• Language: English
• Subjects: 1-Methyl-3-isobutylxanthine - pharmacology; 8-Bromo Cyclic Adenosine Monophosphate - pharmacology; Adenosine-5'-(N-ethylcarboxamide) - pharmacology; Animals; Aorta - cytology; Biological Transport - drug effects; Cesium - metabolism; Cyclic AMP - pharmacology; Endothelium, Vascular - enzymology; Iloprost - pharmacology; Nuclear Magnetic Resonance, Biomolecular; Potassium - metabolism; Purinergic P1 Receptor Agonists; Receptors, Prostaglandin - agonists; Sodium-Potassium-Exchanging ATPase - drug effects; Swine
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.1997.7908

Using anin vitrocell system and Cs+NMR techniques we were able to show that porcine aortic endothelial cells (PAEC) reduce their Na+-K+-ATPase activity upon an increase in intracellular cAMP. Reduction in the pump rate was due to phosphorylation of the α-subunit of the ATPase as shown by immunoprecipitation. Apart from a pump inhibiton using 8-Br-cAMP and IBMX, we were also able to show that changes in the Na+-K+-ATPase activity could be mediated by the adenosine-A2and prostaglandin receptor agonists 5′-N-Ethylcarboxamidoadenosine and Iloprost, respectively. Parallel to a decrease in pump activity we also observed a decrease in intracellular Cs+, indicating opening of K+channels.