ISSN:
1432-1254
Keywords:
Key words Circadian rhythm
;
Locomotor activity
;
Exercise
;
Heat stress
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geography
,
Physics
Notes:
Abstract Several timed daily environmental cues alter the pattern of nycthemeral variations in body core temperature in rodents. The present study investigated the effect of timed exercise on variations of daily body core temperature. Male rats were housed in cages with a running wheel at an ambient temperature of 24° C with a 12:12 h light/dark cycle. Timed daily exercise rats (TEX) were allowed access to the wheel for 6 h in the last half of the dark phase, freely exercising rats (FEX) could run at any time, and sedentary rats (NEX) were not allowed to run. After a 3-week exercise period, all animals were denied access to the wheel. The intraabdominal temperatures (T ab) and spontaneous activities of rats were measured for 6 days after the exercise period. The T ab values of the TEX rats were significantly higher than those of the other two groups only in the last half of the dark phase, while T ab in the FEX and NEX rats showed no significant difference. The specific T ab changes in the TEX rats lasted for 2 days after the exercise period. Spontaneous activity levels were higher in the TEX rats than the FEX and NEX rats in the last half of the dark phase for 1 day after the exercise period. The results suggest that daily exercise limited to a fixed time per day modifies nycthemeral variations of body core temperature in rats so that the temperature increases during the period when the animals had previously exercised. Such a rise in body core temperature is partly attributed to an increase in the spontaneous activity level.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004840050034
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