Effects of dietary fish oil and corn oil on bile flow and composition in rats

Abstract

A study was undertaken to compare the effects of n-3 and n-6 fatty acids on bile flow and bile composition in rats. Male Sprague-Dawley rats were fed diets containing either 10% corn oil or 8% fish oil (MaxEPA) and 2% corn oil for a period of 2 weeks. At the end of the feeding period, rats were fitted with exteriorized cannulas in the duodenum and bile duct. While a glucose-saline solution was infused through the duodenal cannula at 3.0 mL/h, bile was collected hourly for 6 hours. Bile secretion was found to be greater in the fish oil fed rats than the corn oil fed animals. As a function of bile flow per hour, the bile acid, cholesterol and phospholipid output appeared to be greater in the group receiving fish oil. However, when concentration was determined, the effect of diet disappeared. Diet had an effect on the fatty acid composition of bile phospholipids. Rats fed fish oil had significantly more eicosapentaenoic and docosahexaenoic acids in the bile phospholipids than those fed corn oil while those fed corn oil had higher levels of arachidonic acid.