Free fatty acids in an animal model of Reye's syndrome.

Recent studies have indicated that viral infections, aspirin treatment and hyperammonemia are associated with Reye's syndrome. It has also been reported that free fatty acids in serum and total lipids in the liver of Reye's syndrome patients are elevated during illness. The role of the lipid changes in the development of the disorder cannot be optimally studied in human patients, because infection and aspirin ingestion occur prior to the earliest symptoms of Reye's syndrome. Effects of influenza B infection, aspirin treatment and hyperammonemia on the level of free fatty acids, total lipids and triacylglycerols in serum and liver of an animal model of Reye's syndrome are reported here. Hyperammonemia was produced in young, male ferrets either by feeding them small amounts of an arginine-deficient diet after overnight fasting or by an intraperitoneal injection of jackbean urease. The ferret model resembled Reye's syndrome in developing increased levels of individual and total serum free fatty acids, liver triacylglycerol and total lipids. The results also indicate that influenza infection or aspirin treatment, or both, while increasing the severity of encephalopathy in the deficient ferrets, did not cause a significant change in the level of serum free fatty acids. Other results suggest that elevation of serum ammonia, serum free fatty acid or liver lipids, either singly or in various combinations, does not provide conditions that can explain the rapidly developing encephalopathy in the arginine-deficient ferrets.