ISSN:
1439-6327
Keywords:
Exercise
;
Norepinephrine
;
Metabolism
;
Oxygen consumption
;
Running
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The effects of norepinephrine (NE) injection (300 Μg·kg−1 of body weight) on oxygen consumption ( $$\dot V_{O_2 }$$ ), carbon dioxide production ( $$\dot V_{CO_2 }$$ ) and respiratory exchange ratio (R) were investigated in female rats after 1 h of running on a treadmill (21.5 m·min−1) at 10% inclination. Six groups of animals were injected respectively at various times after the exercise (1, 3, 6, 9, 21, and 47 h), and were compared to six non-exercised groups injected at corresponding times. $$\dot V_{O_2 }$$ and $$\dot V_{CO_2 }$$ were monitored continuously during the 20 min preceding injection and for the 60 min following it. The increases in $$\dot V_{O_2 }$$ and $$\dot V_{CO_2 }$$ , and the decrease in R were of similar magnitude in both exercised and non-exercised rats (about 30% and 20% for $$\dot V_{O_2 }$$ and $$\dot V_{CO_2 }$$ , respectively, and −12% for R). Peak $$\dot V_{O_2 }$$ and R values attained after NE injection varied however with time of injection, specially in exercised animals 1 and 9 h after the run. Exercise significantly delayed time of response to NE for $$\dot V_{O_2 }$$ and $$\dot V_{CO_2 }$$ particularly 1 and 9 h after the running bout. It is concluded that time of day, exercise, and time elapsed after exercise are important factors to consider when studying metabolic responses to catecholamines. Furthermore, it is suggested that such experimental controls might be meaningful in human studies as well.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00422983
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