Relation of Fat Deficiency Symptoms to the Polyunsaturated Fatty Acid Content of the Tissues of the Mature Rat

Abstract

Summary1. Caloric restriction, causing severe emaciation, followed by ad libitum feeding on the same fat-deficient diet, precipitated symptoms of fat-deficiency in mature rats. When the rats, after depletion, were maintained on the fat-free diet ad libitum for sufficiently long periods, spontaneous recovery was observed.2. The tissues of these rats were analyzed for linoleic, linolenic and arachidonic acids by the spectrophotometrie method. The concentrations of linoleic and arachidonic acids in the body fat were found to vary with the appearance of the symptoms; it was high at the end of the depletion period, and low at the stage when fat deficiency symptoms were present. The higher levels of linoleic and linolenic acids at the time of recovery, after a long period on the fat-free diet, are considered as further evidence for the synthesis of essential fatty acids in the mature rat.3. Supplementation of ethyl linoleate increased the level of arachidonate in the body fat.