Existence of Fatty Acid Peroxides in Normal Blood and Tissues of Man and Animals.

Abstract
1. Evidence is presented for presence of fatty acid peroxides in normal animal tissues and in blood. Total fatty acid fractions isolated from tissues yielded positive values with the thiobarbituric acid method and with indophenol dye and thiocyanate methods. Blood, which was not found to react positively by the 3 methods on isolated fatty acids, contained fatty acid peroxides from their ability to diminish induction period of the lipoxidase-linoleate system. 2. A modified method in presence of 1.2 × 10-4 M ferric chloride has been developed for thiobarbituric acid reaction, which apparently yields values for fatty acid peroxides in blood as well as in tissues.