Changes in rat plasma-free fatty acid composition under oxidative stress induced by carbon tetrachloride: decrease of polyunsaturated fatty acids and increase of palmitoleic acid.

In order to measure the changes in antioxidant levels and the composition of plasma-free fatty acids resulting from oxidative stress, male Fisher rats were given a twice weekly subcutaneous injection of a 50% solution of carbon tetrachloride (CCl4) in corn oil for a period of 2 to 13 weeks. The dosage was 1.3 ml/kg of body weight. This treatment significantly suppressed the gain of body weight compared with control rats receiving the same dosage of corn oil. Liver weight of the two groups was similar while necrosis and hyperplasia of hepatocytes and liver fibrosis were observed in CCl4 treated rats. Increased levels of plasma glutamate-oxalacetate transaminase and glutamate-pyruvate transaminase were indicative that hepatocyte necrosis was induced by CCl4. Increased oxidative stress in CCl4 treated rats was indicated by a significant decrease of liver ascorbate and a decrease in the plasma ratio of polyunsaturated fatty acids (PUFA) to total free fatty acids. Interestingly, a significant increase of palmitoleic acid was observed in CCl4 treated rats, which may compensate for the loss of PUFA. The possibility of using the plasma composition of PUFA and palmitoleic acid as a marker of oxidative stress is discussed.