Red cell and plasma antioxidant components and atherosclerosis in Japanese quail: A time-course study

Our study aims to examine changes in red cell and plasma antioxidant components in relation to age and aortic lesion development in SUS Japanese quail during a 12-week period of dietary cholesterol supplementation. One hundred adult SUS males were divided into 5 treatment groups and were fed either a control or a cholesterol-supplemented (0.5% w/w) diet. Birds were sacrificed after 0, 4, 8 and 12 weeks on the diets and examined for plaque development and antioxidant components status. "Aging" was associated with increases in the activity of red cell SOD and GPx. Significant correlations among red cell GRd, GPx and SOD activities were found in old but not in younger adult birds. Plasma triglyceride levels increased, while plasma tocopherol level decreased with aging. With birds on the cholesterol diet, plaque score increased with time and regressed significantly but negatively on plasma cholesterol level at the initial stage of atherogenesis. Aortic triglycerides showed a drastic increase in the early stage of atherogenesis but returned to the pretreatment level during the late stage. Conversely, aortic cholesterol showed small increases at the early stages but large increases during the late stage. Red cell antioxidant components showed increases at the early and late stages with a leveling off at the mid stage. Plasma GRd activity decreased while plasma tocopherol level increased (after adjusting for the effect of effect of aging) with cholesterol feeding. We conclude that the increase in plasma triglyceride levels and associations among red blood cell GRd, GPx and SOD activities in "old" birds fed the control diet resembled the situation in the early stages of atherogenesis in the cholesterol-fed birds. This would be consistent with the known permissive effect of aging on the course of atherogenesis. Triglycerides may play a crucial role in atherogenesis during the early phase of lesion development. Early and late phases of lesion development are biochemically distinct, indicating that the process of atherogenesis is a highly dynamic one. The patterns of antioxidant alterations associated with lesion development showed a complex time-dependence.