Dependence of lipid-lipoprotein metabolism on exercise intensity in experimental fatty liver rats

To develop experimental fatty liver, Wistar male rats were fed a high fat, high cholesterol (Cho) diet for 6 weeks after which their diet was changed to standard chow. The animals were then divided by random selection into a sedentary group (SG) and four treadmill exercise groups for 6 weeks as follows: walking group (WG, 10 m/min, 60 min); low-speed running group (LRG, 20 m/min, 30 min); middle-speed running group (MRG, 30 m/min, 20 min) and high-speed running group (HRG, 40 m/min, 15 min). The serum concentration of very low density lipoprotein (VLDL) and low density lipoprotein (LDL)-Cho decreased, and high density lipoprotein (HDL)-Cho increased in WG compared with the other three exercise groups. Hepatic triglyceride (TG) was significantly lower (P less than 0.05) in WG than in SG. Hepatic Cho was lower in HRG than in the other three exercise groups, and Cho in the aortic wall was higher. The results suggest that light exercise, such as walking might be more beneficial to lipid-lipoprotein metabolism than strong exercise, such as high-speed running. This is consistent with suggestion that light exercise might be effective in clinical treatment for hyperlipidemia, arteriosclerosis or fatty liver.