Effect of exercise on serum and hepatic lipids in rats fed high fat diets

Abstract

The effect of exercise on the lipid concentration in serum and tissues was studied in: 1) 4 groups of 100 rats each fed high fat diets containing 22 or 54% saturated coconut oil or unsaturated soya oil; 2) 185 rats fed Hartroft diets; 3) 75 chow-fed controls. Approximately half of each group were exercised 8 hr daily. Exercise was effective in reducing serum total lipid and cholesterol concentrations only in those animals in which the levels were elevated by high fat intake, but did not alter cardiac-renal lipids. When tissue lipid concentrations were normal, as in rats fed chow diets, they were not changed by exercise. Serum total lipid and cholesterol concentrations were high in rats fed 54% coconut oil diets and normal in those fed soya oil diets. Both coconut and soya oil caused fatty livers, coconut oil causing the lipid to be rich in glycerides, soya oil rich in cholesterol. Cardiac and renal lipid concentrations were unaffected by high fat diets. Exercised rats, as opposed to sedentary controls fed a Hartroft diet containing 0.3% cholate for 9 months, had significantly lower serum total lipid and cholesterol concentrations, but tissue lipid and cholesterol concentrations were similar.