اثرات آنتي اكسيداني و آنتي آتروژنيك اسيدآمينه ايزولوسين بر ديواره شريان هاي كرونري خرگوش هاي با كلسترول بالا

Antioxidant and Antiatherogenic Effects of L-Isoleucine on Coronary Arteries of Hypercholesterolemic Rabbits

Background and Objectives: Lipid Peroxidation is nominated as a key event in the development of atherosclerosis. Some evidences suggest that oxidative modifications of amino acids in low density lipoprotein (LDL) particles lead to its conversion to an atherogenic form which is taken up by macrophages. Therefore the reduction of oxidative modification of lipoproteins by increasing plasma antioxidant capacity (AC) could be an effective method in preventing cardiovascular diseases. In this experimental study, antioxidant and antiatherogenic effects of L-Ile were investigated in hypercholesterolemic rabbits. Materials and Methods: Fifteen male New Zealand white rabbits were divided into three groups (normal control, hypercholesterolemic control and hypercholesterolemic treated with L-Ile). Animals were fed with special diets for five weeks and then plasma total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), conjugated diens (CDs), malondialdehyde (MDA) and AC were measured. Coronary arteries were obtained in order to measure fatty streaks formation by histological studies. Results: Plasma level ofCDs was decreased in L-Ile treated group compared to the hypercholesterolemic control group, but it was not significant. The levels of plasma TC, LDL-C, HDL-C and AC, in the treated group had an increase in comparison with the hypercholesterolemic control group, while the levels of plasma TG and MDA were decreased. The mean size of produced fatty streaks also showed significant reduction in the treating group compared to hypercholesterolemic control group. Conclusion: The results showed that L-Ile has prevented fatty streaks formation by increasing plasma antioxidant capacity and decreasing lipid peroxidation in hypercholesterolemic rabbits.