Differential MAP kinase activation and Na(+)/H(+) exchanger phosphorylation by H(2)O(2) in rat cardiac myocytes.
Am J Physiol Cell Physiol
; 281(5): C1542-50, 2001 Nov.
Article
in En
| MEDLINE
| ID: mdl-11600417
ABSTRACT
Bursts in reactive oxygen species production are important mediators of contractile dysfunction during ischemia-reperfusion injury. Cellular mechanisms that mediate reactive oxygen species-induced changes in cardiac myocyte function have not been fully characterized. In the present study, H(2)O(2) (50 microM) decreased contractility of adult rat ventricular myocytes. H(2)O(2) caused a concentration- and time-dependent activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), p38, and c-Jun NH(2)-terminal kinase (JNK) mitogen-activated protein (MAP) kinases in adult rat ventricular myocytes. H(2)O(2) (50 microM) caused transient activation of ERK1/2 and p38 MAP kinase that was detected as early as 5 min, was maximal at 20 min (9.6 +/- 1.2- and 9.0 +/- 1.6-fold, respectively, vs. control), and returned to baseline at 60 min. JNK activation occurred more slowly (1.6 +/- 0.2-fold vs. control at 60 min) but was sustained at 3.5 h. The protein kinase C inhibitor chelerythrine completely blocked JNK activation and reduced ERK1/2 and p38 activation. The tyrosine kinase inhibitors genistein and PP-2 blocked JNK, but not ERK1/2 and p38, activation. H(2)O(2)-induced Na(+)/H(+) exchanger phosphorylation was blocked by the MAP kinase kinase inhibitor U-0126 (5 microM). These results demonstrate that H(2)O(2)-induced activation of MAP kinases may contribute to cardiac myocyte dysfunction during ischemia-reperfusion.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Sodium-Hydrogen Exchangers
/
Mitogen-Activated Protein Kinases
/
JNK Mitogen-Activated Protein Kinases
/
Hydrogen Peroxide
/
Myocardium
Limits:
Animals
Language:
En
Journal:
Am J Physiol Cell Physiol
Journal subject:
FISIOLOGIA
Year:
2001
Document type:
Article
Affiliation country: