Effect of Moderate Treadmill Exercise on Hepatic Lipid Metabolism in Rats

Several and complex factors cause accumulation of large amounts of body fat as well as a disparity between energy intake and output. Generally, any increase in bodyweight can be attributed to the elevation in daily food intake and the reduction in energy expenditure. Several functions could be achieved by moderate exercise including maintaining an optimum body weight and muscle mass, lowering abdominal fat and increasing lipid catabolism. However, the exact molecular mechanisms involved remain understudied. Our study was designed mainly to evaluate the influence of moderate treadmill exercise on body metabolism with special reference to hepatic lipid metabolism. Twenty adult male Sprague Dawley rats weighting 200±20 gm were randomly assigned to either sedentary or exercised groups. The exercise protocol lasted for 20 mins/ 5 times / week along 4 weeks. Although no significant changes in body weight, insulin and corticosterone levels, there was a significant decrease in fasting blood glucose and serum leptin levels (81.06%and 75.49% respectively). The current exercise regime significantly increased serum high density lipoprotein (HDL-c) level (127.56%) and significantly decreased serum triacylglycerol (TAG), low density lipoprotein (LDL-c) and very low-density lipoprotein (VLDL-c) levels (75.50%, 62.83% and 74.48% respectively). Also, treadmill exercise significantly upregulated the hepatic expression of acetyl-CoA oxidase (ACO) and carnitine palmitoyl CoA transferase 1 (CPT1) (173% and 148% respectively) as well as significantly downregulated the hepatic acetyl-CoA carboxylase (ACC) (52%) but not fatty acid synthase (FAS) mRNA expression. Overall, these results suggest a beneficial effect of moderate treadmill exercise hepatic lipid metabolism.