Journal of Comparative Physiology B

, Volume 164, Issue 7, pp 536–542

The optimal depot fat composition for hibernation by golden-mantled ground squirrels (Spermophilus lateralis)

  • C. L. Frank
  • K. B. Storey
Article

DOI: 10.1007/BF00261394

Cite this article as:
Frank, C.L. & Storey, K.B. J Comp Physiol B (1995) 164: 536. doi:10.1007/BF00261394

Abstract

Golden-mantled ground squirrels (Spermophilus lateralis) are herbivores that hibernate during winter. Although little is known about the nutritional/physiological constraints on hibernation, numerous studies have demonstrated that increasing the amount of linoleic acid (a polyunsaturated fatty acid) in the diet enhances hibernation. This is probably because high linoleic acid diets reduce the melting points of the depot fats produced for hibernation which makes them more metabolizable at low body temperatures. This suggests that a major limitation on hibernation may be obtaining enough linoleic acid in the diet for proper hibernation. In all previous studies, however, the amount of linoleic acid in the diets of free-ranging animals was either not considered, or the range of dietary linoleic acid contents in the experiments was less than that of natural diets. It is thus not known whether the amount of linoleic acid available to hibernators under natural conditions actually limits their torpor patterns. A series of laboratory feeding and hibernation experiments were conducted with S. lateralis and artificial diets with different linoleic acid contents that were either below or above the linoleic acid content of the natural diet. The results demonstrated that when dietary linoleic acid contents are either below or above natural levels, hibernation ability is greatly reduced. Hibernation ability was reduced when the squirrels were maintained on a high linoleic acid diet probably by the production of toxic lipid peroxides in brown adipose tissues. The results indicate that there is an optimal level of dietary linoleic acid for proper hibernation, and this is equal to that of the natural diet. The amount of linoleic acid available in the diet thus does not limit hibernation under normal natural conditions.

Key words

Hibernation Ground squirrel Lipids Diet Polyunsaturates 

Abbreviations

BAT

brown adipose tissue

bm

body mass

FA

fatty acid

PUFA

polyunsaturated fatty acid

Ta

ambient temperature

Tb

body temperature

WAT

white adipose tissue

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • C. L. Frank
    • 1
    • 2
  • K. B. Storey
    • 3
  1. 1.Department of Ecology and Evolutionary BiologyUniversity of CaliforniaIrvineUSA
  2. 2.The White Mountain Research StationBishopUSA
  3. 3.Institute of BiochemistryCarleton UniversityOttawaCanada
  4. 4.Department of BiologyCarleton UniversityOttawaCanada

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