This study examined the effects of major burn injury on the cellular distribution of several PKC isoforms in adult rat hearts and examined the hypothesis that PKC plays a regulatory role in cardiac myocyte cytokine secretion. Burn trauma was given over 40% TBSA in SD rats. An in vitro model of burn injury included addition of burn serum, 10% by volume, to primary cardiomyocyte cultures (collagen perfusion of). In vivo burn injury produced re-distribution of PKC delta (PKC ), PKC epsilon (PKC ), and PKC alpha (PKC ) from the cytosol (soluble) to the membrane (particulate) component of the myocardium. This activation of the PKC isoforms was evident 2 hours after burn injury and progressively increased over 24 hours post burn. Addition of burn serum to isolated myocytes produced similar PKC isoform re-distribution from the soluble to the particulate compartment, promoted myocyte calcium and sodium loading, and promoted robust myocyte secretion of inflammatory cytokines similar to that reported after in vivo burn injury. Pre-treating cardiomyocytes with either calphostin or with Protein Kinase C epsilon Inhibitory Peptide, a potent inhibitor of PKC epsilon, prevented burn serum-related re-distribution of the PKC isoform and prevented burn serum-related cardiomyocyte secretion of TNF-, IL-1, IL-6, and IL-10. These data suggest that the PKC epsilon isoform plays a pivotal role in myocardial inflammatory response to injury, altering cardiac function by modulating cardiomyocyte inflammatory cytokine response to injury.