Comparison of natural and pharmacological torpor in homeothermic
animals: determination of the activation energy of metabolism
Abstract
We analyzed the correspondence of the activation energy of metabolism
(E) in rats under pharmacological torpor and hypothermia to the findings
of the WBE-theory of ecology based on the studies of hibernating
mammals: true hibernators and daily heterotherms. We found that in rats
in a state of pharmacological torpor lasting about a day, E was close to
that of daily heterotherms, while in anesthetized rats with hypothermia
lasting for several hours, E was significantly lower, which is in sharp
contradiction with the theory. We have shown that in rats classified as
homeotherms, at short-term hypothermia the changes in metabolic rate
precede the changes in body temperature by the interval Δt. We
hypothesized that in poikilotherms, changes in metabolic rate may lag
changes in body temperature by (-) Δt. Given this time shift, we
proposed an approach to E correction in order to minimize its deviation
from theoretical predictions.