Comparação morfológica e bioquímica entre ratos envelhecidos alimentados com dieta hiperlipídica e com óleo de canola / Morphological and Biochemical Comparison among Aged Rats Fed with Hyperlipidic and Canola Oil Diet

ABSTRACT

PURPOSE: To observe cardiovascular and metabolic changes due to canola oil diet (rich in n-3 fatty acid). METHODS: Forty five rats were followed during 15 months separated in three groups. In group aged (A), they received a regular diet. In group H, animals received a hyperlipidic diet and in group O they received a canola oil diet. The rats were fed for 15 months after weaning. At the end of the experience a blood analysis was performed and heart and aorta were analyzed. The total lipids were extracted and the LDL, VLDL and HDL were determined. RESULTS: Total cholesterol and triglyceride levels were not different among groups. Differences were found in body and cardiac weight, the thickness of the right and left ventricular wall, aorta and pulmonary diameters, HDL and LDL (p < 0.05). Smallest values of the cardiac weight and thickness of the ventricular walls were found in group O. The aorta and pulmonary internal diameters were smaller in group H. The HDL was 40greater in group O than in groups A and H while the LDL was more than 80lower in group O than in groups A and H. Differences in survival curves between groups H x A and between H x O were significant (p < 0.05) but not between groups A x O (p = 0.48). CONCLUSION: Aged rats fed with canola oil diet (rich in n-3 fatty acid) presented morphological cardiovascular and metabolic changes less important in magnitude than old animals and, mainly, the same age animals under hyperlipidic diet.