Background and aims: Atherosclerosis develops in different locations of the vasculature with different degree, which may result from different antioxidant/prooxidant status. This study investigated the effect of high-fat, high-cholesterol chows, with or without vitamin E supplement (450 mg/kg diet), on lipid peroxide levels, glutathione peroxidase expression, and atheroma formation in ascending aorta, pulmonary arteries and thoracic aorta.
Methods: Sixty-four rabbits were divided to be fed with 4 different chows for 6 weeks. The percentage of atherosclerosis was measured. Plasma and vascular glutathione peroxidase activity and mRNA expression, and lipid peroxide levels were also assayed.
Results: Rabbits on high-fat, high-cholesterol chows had higher lipid peroxide levels and more atherosclerosis in ascending aorta and pulmonary arteries. Tissues in thoracic aorta had higher glutathione peroxidase activity and mRNA expression without any significant increase in lipid peroxide levels and atherosclerosis. Vitamin E supplement decreased plasma lipid peroxide levels, but not in tissues, and thus could not prevent atherosclerosis.
Conclusion: Higher glutathione peroxidase expression in the thoracic aorta inhibits oxidative stress enhancement and atheroma progression induced by high-fat, high-cholesterol chows. Vitamin E supplement at the current dosage and duration could not prevent atheroma formation.
(c) 2007 S. Karger AG, Basel.