Different effect of ouabain on endothelin-1-induced extracellular signal-regulated kinase stimulation in rat heart and tail artery.
Endogenous ouabain may play a role in the control of cardiovascular system function. In this study, we investigated the effects of a long-term ouabain treatment on basal and endothelin-1 (ET-1)-induced phosphorylation of cardiac and vascular extracellular signal-regulated kinases 1 and 2 (ERK-1 and ERK-2), which are involved in several cardiac and vascular physiologic and pathologic conditions. Our results show that the hearts from ouabain-treated rats have a higher basal level of ERK-1 and ERK-2 phosphorylation compared with untreated rats. Perfusion of the hearts with ET-1 increased ERK-1 and ERK-2 phosphorylation both in ouabain-treated and in control rats, with a larger stimulatory effect in ouabain-treated animals. On the contrary, exposure of endothelium-free tail artery to ET-1 increased ERKs phosphorylation both in treated and untreated rats, but this effect was blunted in ouabain-treated rats. These findings demonstrate that ouabain treatment has opposite effects on basal and ET-1-induced ERKs phosphorylation in the heart and in the tail artery of the rat.
Ceolotto
Giulio
G
Departments of Clinical and Experimental Medicine, University of Padua, Padua, Italy.
Sartori
Michelangelo
M
Papparella
Italia
I
Candiotto
Marco
M
Baritono
Elisabetta
E
Filippelli
Amelia
A
Cargnelli
Gabriella
G
Luciani
Sisto
S
Semplicini
Andrea
A
Bova
Sergio
S
D000818:Animals; D001158:Arteries / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology*; D003331:Coronary Vessels / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology*; D019332:Endothelin-1 / Q000494:pharmacology*; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000096:biosynthesis*; D010042:Ouabain / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013623:Tail / Q000098:blood supply*
D019332:Endothelin-1; D010042:Ouabain; D020928:Mitogen-Activated Protein Kinases