A comparative study of brown adipose tissue oxidative metabolism among temperature-acclimated spermophilus lateralis, spermophilus tereticaudus and Amnospermophilus leucurus.

Abstract

1. 1. Brown adipose tissue (BAT) oxidative enzyme activities levels, mass and protein content were determined for control and heat- and cold-acclimated Spermophilus lateralis, Spermophilus tereticaudus and Amnospermophilus leucurus. 2. 2. S. lateralis and S. tereticaudus respond to prolonged temperature stress by undergoing compensatory changes in oxidative enzyme levels that may facilitate greater nonshivering thermogenesis in the cold and increased chemical thermosuppresion in the heat. 3. 3. S. tereticaudus and A. leucurus, but not S. lateralis, showed significant changed in BAT mass. 4. 4. S. tereticaudus and S. lateralis, but not A. leucurus, showed significant changes in protein per g BAT. 5. 5. The similarity of BAT enzymatic responses between S. lateralis and S. tereticaudus and dissimilarity of the BAT response of A. leucurus suggest an intrinsic physiological difference between hibernators and non-hibernators rather than between desert and mountain species. © 1981.