Abstract
Aging, obesity and underexercise are one of the risk factors for atherosclerosis. We evaluated the effect of dietary restriction and physical exercise to risks for atherosclerosis in spontaneously hypertensive rats (SHR). We randomly assigned 42 rats to two experimental diet groups, 100% group taking food ad libitum, and 70% group taking food 70% of the average food consumption. Each group was further assigned to two exercise conditions, sedentary group (Sd100, Sd70) and exercise group (Ex100, Ex70), 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. Ex- and -70% groups independently decreased the physiological risks for atherosclerosis: growth rate of body weight, blood pressure and serum HDL. It showed tendency that the oxidative stress index in cranial and caudal portion of aorto-renal bifurcation and Ex70 was high. Superoxide dismutase activity of heart, kidney, and serum in Ex70 was the highest. These data indicate that dietary restriction and exercise conditions improve the risk for atherosclerosis in SHR, through the mechanism which is not connected with oxidative stress. [J Physiol Sci. 2008;58 Suppl:S188]
