Role of arachidonic acid in the regulation of the inflammatory response in TNF-alphatreated rats

ABSTRACT. Background: This study examined whether adding arachidonic acid (AA) to a fish oil diet would alter certain of the anti-inflammatory effects of fish oil in response to tumor necrosis factor (TNF) infusion in rats. Methods: AA was given at 0.08 wt % of diet for 6 weeks. The total fat in each diet provided 20 % of dietary energy. Four groups were pair-fed sunflower oil (S), S+AA, fish oil (F), or F+AA for 6 weeks. At the end of feeding, each animal received TNF-α (20 μg/kg) infusion for 3 hours. After 1 hour of TNF infusion, a euglycemic and hyperinsulinemic clamp (10 mU/min per kilogram of insulin) was used to determine the actions of insulin. The insulin-stimulated glucose utilization in liver, muscle, and fat was deter-mined by using 14C-deoxyglucose. The plasma glucose, insulin, and corticosterone levels were determined a