DIETS CONTAINING CORN-OIL, COCONUT OIL AND CHOLESTEROL ALTER VENTRICULAR HYPERTROPHY, DILATION AND FUNCTION IN HEARTS OF RATS FED COPPER-DEFICIENT DIETS

Cardiac hypertrophy and function were evaluated in rats fed diets cont aining deficient, marginal or adequate levels of copper. The fat conce ntration of the diets was either 10 g/100 g corn oil, 10 g/100 g cocon ut oil or 10 g/100 g coconut oil + 1 g/100 g added cholesterol. Left v entricular (LV) wall thickening of hearts in rats fed copper-deficient diets was characterized by greater (P < 0.05) LV free wall width, reg ardless of dietary fat type, and greater intraventricular septum width in the rats fed corn oil. Rats fed the copper-deficient diet with coc onut oil + cholesterol had LV chamber volumes that were twofold larger than those of rats fed the copper-deficient diet with coconut oil or corn oil. Copper deficiency reduced LV chamber volume only in rats fed coconut oil + cholesterol. Cardiac LV end diastolic pressure in rats fed copper-deficient diets was twofold larger than in copper-adequate and copper-marginal groups fed corn oil or coconut oil. Hearts from ra ts fed the copper-deficient diet with corn oil compared with those fro m rats fed the copper-deficient diet with coconut oil + cholesterol ha d greater right ventricular (RV) and LV end diastolic pressures, LV pr essures and LV and RV maximal rates of positive pressure development. Our data suggest that cardiac adaptations in rats fed copper-deficient diets are influenced by dietary fat type: 1) hearts of rats fed the c opper-deficient diet with corn oil were concentrically hypertrophied, whereas cardiac contractility was maintained in the presence of high p reload; 2) preload and contractility in hearts of coconut oil-fed rats was greater than cardiac response to cholesterol addition to the coco nut oil diet; 3) hearts in copper-deficient rats fed coconut oil + cho lesterol exhibited eccentric hypertrophy and ventricular dysfunction.