First published online December 3, 2004
Journal of Experimental Biology 207, 4525-4533 (2004)
Published by The Company of Biologists 2004
doi: 10.1242/jeb.01307
Metabolism of normothermic woodchucks during prolonged fasting
Shannon P. Reidy* and
Jean-Michel Weber
Biology Department, University of Ottawa, Ontario, Canada

View larger version (26K):
[in a new window]
|
Fig. 1. Changes in body mass of adult woodchucks and rabbits during prolonged
fasting. (A) Body mass expressed as % of initial mass measured in fed animals
(the value for day 0), and (B) rate of absolute mass loss in g kg-1
day-1. Values are means ± S.E.M. for summer
woodchucks (N=4), spring woodchucks (N=4) and rabbits
(N=9).
|
|

View larger version (31K):
[in a new window]
|
Fig. 2. Mean rate of oxygen consumption over a 24 h period of adult woodchucks and
rabbits during prolonged fasting. Values are means ± S.E.M.
(A) Absolute rates in µmol O2 kg-1 min-1
and (B) values expressed as % of initial metabolic rate measured on day 0 in
fed animals. Summer woodchucks (N=4), spring woodchucks
(N=4) and rabbits (N=9).
|
|

View larger version (23K):
[in a new window]
|
Fig. 3. Body temperature of woodchucks and rabbits before and during a prolonged
fast. Values are means ± S.E.M. for summer woodchucks
(N=4), spring woodchucks (N=4) and rabbits (N=9).
* indicates significant differences from the fed values (day 0)
within each group.
|
|

View larger version (19K):
[in a new window]
|
Fig. 4. Fuel selection in woodchucks and rabbits before and during a prolonged
fast. The % contributions of carbohydrates, lipids and proteins to total
oxygen consumption are given for fed animals (A), for animals fasted for 1 day
(B) and for animals fasted for 2-7 days (C). Values are means ±
S.E.M. for summer woodchucks (N=4), spring woodchucks
(N=4) and rabbits (N=9). Values of the same fuel type marked
with the same symbol are significantly different from each other.
|
|

View larger version (21K):
[in a new window]
|
Fig. 5. Urinary excretion rates of woodchucks and rabbits before and during
prolonged fasting. (A) Absolute rates of N excretion (N=4 for spring
and summer woochucks, N=9 for rabbits). (B-E) The relative
contributions of urea (B), ammonia (C), creatinine (D) and uric acid (E) to
total N excretion. For relative contributions (% of total N excretion), the
values for spring and summer woodchucks were pooled (N=8 for
woodchucks and 9 for rabbits). Values are means ± S.E.M.
*Significant differences from fed values measured on day 0 within
each group.
|
|

View larger version (27K):
[in a new window]
|
Fig. 6. Rates of water consumption and urine production in woodchucks and rabbits
before and during prolonged fasting (N=4 for spring and summer
woochucks, N=9 for rabbits).
|
|
© The Company of Biologists Ltd 2004