We investigated the activation of three subfamilies of MAPKs (ERK, JNKs and @entity1435 ) by oxidative stress in the isolated perfused amphibian heart. Activation of @entity38760 -ERK by 100 micro mol l(-1) @entity274 was maximally observed within 5 min, remained elevated for 30 min and was comparable with the effect of 1 micro mol l(-1) @entity4515 . @entity38760 -ERK activation by @entity274 was inhibited by @entity4286 but not by @entity1441 . The p46 and @entity7286 species of JNKs were maximally activated by 2.5- and 2.1-fold, respectively, by 100 micro mol l(-1) @entity274 within 2 min. JNK activation was still detectable after 15 min, reaching control values at 30 min of treatment. @entity1435 -MAPK was maximally activated by 9.75-fold by 100 micro mol l(-1) @entity274 after 2 min and this activation progressively declined thereafter, reaching control values within 45 min of treatment. The observed dose-dependent profile of @entity1435 -MAPK activation by @entity274 revealed that 30 micro mol l(-1) @entity274 induced maximal phosphorylation, whereas 100-300 micro mol l(-1) @entity274 induced considerable activation of the kinase. Our studies also showed that the phosphorylation of @entity11006 by @entity274 followed a parallel time-dependent pattern and that @entity1441 abolished this phosphorylation. Furthermore, our experiments clearly showed that 30 micro mol l(-1) @entity274 induced a strong, specific phosphorylation of @entity2284 . Our immunohistochemical studies showed that immune complexes of phosphorylated forms of both @entity1435 -MAPK and @entity2284 were strongly enhanced by 30 micro mol l(-1) @entity274 in the perinuclear region as well as dispersedly in the cytoplasm of ventricular cells and that @entity1441 abolished this phosphorylation. These data indicate that oxidative stress is a powerful activator of all three MAPK subfamilies in the amphibian heart. Stimulation of @entity1435 and the consequent phosphorylation of @entity2284 may be important in cardioprotection under such conditions.

Oxidative stress stimulates multiple MAPK signalling pathways and phosphorylation of the small XXXX in the perfused amphibian heart.

@entity7286 :: ('4791', 'Gene') :: ['p52'] @entity274 :: ('CHEBI:16240', 'Chemical') :: ['H(2)O(2)'] @entity2284 :: ('3315', 'Gene') :: ['HSP27'] @entity4515 :: ('CHEBI:60755', 'Chemical') :: ['PMA'] @entity1441 :: ('MESH:C093642', 'Chemical') :: ['SB203580'] @entity38760 :: ('9255', 'Gene') :: ['p43'] @entity1435 :: ('1432', 'Gene') :: ['p38-MAPK', 'p38'] @entity4286 :: ('MESH:C093973', 'Chemical') :: ['PD98059'] @entity11006 :: ('9261', 'Gene') :: ['MAPKAPK2']
@entity2284 :: (3315,Gene) :: ['HSP27']
