Exercise and omega-3 polyunsaturated fatty acid supplementation for the treatment of hepatic steatosis in hyperphagic OLETF rats

Background and aims. this study examined if exercise and omega-3 fatty acid (n3pufa) supplementation is an effective treatment for hepatic steatosis in obese,hyperphagic otsuka long-evans tokushima fatty (oletf) rats. methods. male oletf rats were divided into 4 groups (n = 8 /group): (1) remained sedentary (sed),(2) access to running wheels; (ex) (3) a diet supplemented with 3% of energy from fish oil (n3pufa-sed); and (4) n3pufa supplementation plus ex (n3pufa+ex). the 8 week treatments began at 13 weeks,when hepatic steatosis is present in oletf-sed rats. results. ex alone lowered hepatic triglyceride (tag) while,in contrast,n3pufas failed to lower hepatic tag and blunted the ability of ex to decrease hepatic tag levels in n3pufas+ex. insulin sensitivity was improved in ex animals,to a lesser extent in n3pufa+ex rats,and did not differ between n3pufa-sed and sed rats. only the ex group displayed higher complete hepatic fatty acid oxidation (fao) to coand carnitine palmitoyl transferase-1 activity. ex also lowered hepatic fatty acid synthase protein while both ex and n3pufa+ex decreased stearoyl coa desaturase-1 protein. conclusions. exercise lowers hepatic steatosis through increased complete hepatic fao,insulin sensitivity,and reduced expression of de novo fatty acid synthesis proteins while n3pufas had no effect. © 2012 sarah j. borengasser et al.