High fat diet and liver damage induced by biliary obstruction in the rat

There is a great body of evidence linking a high fat diet with the formation of gallstones. However, the effect of fat per se on obstructive liver damage (not involving gallstone formation) has not been assessed. The aim of this work was to study the effect of a high fat diet on liver damage induced by bile duct ligation in rats. Male 21-day-old Wistar rats were divided into two groups: group 1 received standard Purina chow diet 5001 containing 4.5% fat, group 2 received Purina chow diet 5001 enriched with 33% pork fat. Animals were allowed food and water ad libitum for 5 weeks. Obstructive jaundice was induced by double ligation and division of the common bile duct. The animals were sacrificed 1 week after biliary obstruction. Control animals were sham operated. Serum bilirubins and alkaline phosphatase, gamma-glutamyl transpeptidase and glutamic pyruvic transminase enzyme activities increased by biliary obstruction. Glycogen content decreased in the bile duct-ligated rats. These effects were more important in the group fed a 33% fat diet. Our results show that a high animal fat diet increases liver damage in experimental biliary obstruction in rats. Owing to our experimental design (bile duct ligation), the effect of a high fat diet cannot be attributed to an increase in the formation of gallstones but a direct effect must be considered. The mechanism by which fat augmented liver damage can be associated with an increase of total bile content and its toxicity.