2017 Volume 70 Issue 2 Pages 69-75
The prevalence of non-alcoholic fatty liver disease (NAFLD) , which is a risk factor for development of type 2 diabetes mellitus, has increased dramatically in Japan. An effective program for prevention and amelioration of NAFLD is therefore required. In this study, we examined the preventive effects of exercise timing (before or after meals) and exercise duration (6 or 9 weeks) on fatty liver induced by a high-fat diet (HFD) in mice. Accumulation of liver triacylglycerol was prevented by a longer duration of exercise, although the timing of exercise had no significant effect. We then investigated the hepatic expression of mRNAs related to liver lipid synthesis, including peroxisome proliferator-activated receptor γ, a transcription factor induced by an HFD, and its target gene. These mRNAs were significantly suppressed by the exercise training, irrespective of exercise duration. Additionally, the expression of sterol regulatory element-binding protein-1c, a major regulator of de novo lipogenesis in the liver, and its target genes were also suppressed by long-term exercise. These results suggest that long-term exercise is highly effective for prevention of fatty liver and that the same degree of benefit can be obtained from both pre- and post-prandial exercise.
