FRANK, C.L.*; HOOD, W.: The effects of alpha-linolenic acid on mammalian torpor patterns.

Laboratory experiments have demonstrated that the torpor of ground squirrels ( Spermophilus lateralis ) is enhanced by a high linoleic acid diet. Linoleic acid is a polyunsaturated fatty acid (PUFA), and mammals cannot synthesize PUFAs. The diets of free-ranging ground squirrels contain two different PUFA types, however, linoleic and alpha-linolenic acids. Laboratory feeding/hibernation experiments involving S. lateralis were thus conducted to determine the influence diet alpha-linolenic acid content on torpor. The results revealed that a high alpha-linolenic acid diet enhances torpor to a greater extent than increasing diet linoleic acid content by the same amount. Increasing diet alpha-linolenic acid content also increased the amount of lipid peroxidation occurring in some tissues during torpor, however. This study thus demonstrates that the torpor patterns of ground squirrels are influence by total diet PUFA composition, and that lipid peroxidation my be a physiological constrain on mammalian torpor.