On the Dissimilarity of 5′-AMP Induced Hypothermia and Torpor in Mice

A.M. Strijkstra, T. Koopmans, H.R. Bouma, S.F. de Boer, R.A. Hut, A.S. Boerema

Research output: Chapter in Book/Report/Conference proceedingChapterAcademicpeer-review

Abstract

Administration of adenosine-5′-monophosphate (5′-AMP) can induce an artificial but endogenously reversible torpor-like state in mice. The dynamics of body temperature and the relation between body temperature and metabolic rate may indicate the (dis)similarity of this artificial torpor-like state to natural torpor in intact animals. We investigated these in C57BL/6J mice by (1) comparing cooling rates during 5′-AMP induced hypothermia to cooling rates during high workload induced torpor, and by (2) estimating the relative contributions of metabolic suppression and passive temperature (Q 10) effects in the 5′-AMP induced hypothermic state. We did the latter by back-extrapolating the relation between body temperature and metabolic rate in hypothermic conditions to the euthermic temperature level, using calculated Q 10-values. The data indicate that (1) cooling rate in 5′-AMP induced hypothermia is about 1.8 times faster than in natural torpor in workload conditions, and that (2) Q 10 effects can entirely explain the metabolic reduction of 5′-AMP induced hypothermia, indicating that active metabolic suppression may be lacking. Together, this suggests fundamental differences between 5′-AMP induced hypothermia and natural torpor, limiting the validity of the paradigm to the study of effects of hypothermic conditions and temperature related metabolic effects.
Original languageEnglish
Title of host publicationLiving in a Seasonal World
Subtitle of host publicationThermoregulatory and Metabolic Adaptations
EditorsW. Arnold, C. Bieber, E. Millesi, T. Ruf
Place of PublicationBerlin, Heidelberg
PublisherSpringer Verlag
Chapter31
Pages351-362
Number of pages12
ISBN (Electronic)9783642286780
ISBN (Print)9783642286773
DOIs
Publication statusPublished - 2012

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