Protein kinase Cepsilon (PKCepsilon) is a target for reactive oxygen species (ROS). It is activated with reaction products of OH* with phospholipids, which presumably include hydroperoxides of fatty acids or alkylperoxy radicals. Activation of PKCs with reactive oxygen species promotes to mito-K(ATP) channel opening and MPT pore (mitochondrial permeability transition pore) closing thereby it is increasing the resistance of cardiomyocytes to hypoxia-reoxygenation. P38 kinase and tyrosine kinases are targets of ROS. Hydroxyl radical or signaling molecules, resulting from its metabolism, may contribute to the activation of p38-kinase that increases the cardiac tolerance to the impact of ischemia-reperfusion. Src tyrosine kinase and P13-kinase apparently are not targets of ROS. The cardioprotective effect of ROS may be due to the activation of transcription factors NFkappaB and CREB.