Activation of mitogen-activated protein kinases (p38-MAPKs, SAPKs/JNKs and ERKs) by adenosine in the perfused rat heart

Adenosine and mitogen-activated protein kinases (MAPKs) have been separately implicated in cardiac ischaemic preconditioning. We investigated the activation of MAPK subfamilies by adenosine in perfused rat hearts. p38-MAPK was rapidly phosphorylated and activated (10-fold activation, maximal at 5 min) by 10 mM adenosine, as was the p38-MAPK substrate, MAPKAPK2 (4.5-fold). SAPKs/JNKs were activated (5-fold) and ERKs were phosphorylated (both maximal at 5 min), The concentration dependences of activation of p38-MAPK and ERKs were biphasic with a 'high affinity' component (maximal at 10-100 mu M adenosine) and a 'low affinity' component that had not saturated at 10 mM, SAPKs/JNKs were activated only by 10 mM adenosine, These results are consistent with MAPK involvement in adenosine-mediated ischaemic preconditioning. (C) 1998 Federation of European Biochemical Societies.