Caecal function provides the energy of fermentation without liberating heat in the poikilothermic mammal, Heterocephalus glaber.
This paper presents the first report of a mammalian internal organ with a lower temperature than its abdominal surrounds. Heterocephalus glaber, the naked mole-rat, is a poikilothermic mammal that leads a strictly subterranean existence and consumes a high proportion of fibre in its diet. The fermentation chamber in these animals appears to absorb rather than generate heat and the temperature in it was consistently 1.2 +/- 0.5 degrees C (n = 17) lower than rectal temperature. A caecum with a lower temperature than its abdominal surrounds provides an internal heat sink which could be advantageous for metabolic heat dissipation in the plugged humid burrows in which the naked mole-rat permanently resides.
Yahav
S
S
Department of Physiology, Medical School, University of Witwatersrand, Johannesburg, South Africa.
Buffenstein
R
R
D000818:Animals; D001833:Body Temperature Regulation / Q000502:physiology*; D002432:Cecum / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology; D005285:Fermentation / Q000502:physiology; D012377:Rodentia / Q000502:physiology*