Increased Translocation of Cardiac Protein Kinase C β2 Accompanies Mild Cardiac Hypertrophy in Rats Fed Saturated Fat

Signal transduction through protein kinase C (PKC) beta2 may modulate cardiac hypertrophy in pressure-overloaded rat myocardium. Because PKC beta2 can be activated by fatty acids and diacylglycerol, we hypothesized that altering the level and type of dietary fat might modulate cardiac PKC activation and stimulate hypertrophy in otherwise normal rat myocardium. Male Sprague-Dawley rats (n = 32) were randomly assigned to either a low fat [10% total energy intake (TEI)] or high fat diet (40% TEI) based on corn or coconut oil as a source of saturated or unsaturated fat. After 40 d of isoenergetic diet consumption, the heart/body weight ratio was slightly greater in rats fed saturated fat diets compared with those fed unsaturated fat (P = 0.05). Increased activation of PKC beta2, as evidenced by greater membrane translocation, was also observed in all rats fed saturated fat diets (P < 0.01). PKC alpha, beta1 and epsilon did not change. These results suggest that dietary fat type can alter PKC beta2 activation in the heart, and exert a mild hypertrophic effect on the heart.