Abstract
Aging, obesity and underexercise are one of the risk factors for atherosclerosis. We evaluated the effect of these risk factors to atherosclerosis with the oxidative stress index in endothelial cells. We randomly assigned 39 rats to two experimental diet groups, taking food ad libitum (AD) and taking food 70% of the average food consumption (70%). Each group was further assigned to two exercise conditions, sedentary group (SD) and exercise group (EX), swimming for 1 hour/day, 5 days/week. Chronic swimming exercise and experimental diet were started at the same time and continued for 8 weeks. After physiological examination every 2 weeks, we observed the distribution of superoxide and NO production in endothelial cells around aorto-renal bifurcation by using confocal laser-scanning microscopy. We evaluated the endothelial function with the oxidative stress index, the ratio of superoxide production to NO production. Dietary restriction and chronic swimming exercise independently decreased the physiological risks for atherosclerosis, growth rate of body weight, blood pressure and serum triglyceride, and more decreased in concert. There was no difference in the oxidative stress index between arterial portions, among dietary restriction and exercise conditions. There were no difference in the superoxide dismutase activity of heart, kidney, liver, abdominal aorta and serum from dietary restriction and exercise conditions. These data indicate that dietary restriction and exercise conditions improve the risk for atherosclerosis through the mechanism which is not connected with oxidative stress. [J Physiol Sci. 2007;57 Suppl:S206]
