Vagal and sympathetic control of heart rate during exercise by sedentary and exercise-trained rats
Braz. j. med. biol. res
;
25(10): 1045-52, 1992. tab, graf
Article
in English
| LILACS
| ID: lil-134651
ABSTRACT
1. The present investigation was undertaken to study the vagal and sympathetic effects of an acute bout of exercise on ten sedentary (S) and nine trained (T) rats. The exercise training was performed 5 times a week for 13 weeks on a motor treadmill, at 1.0 mph, 15% grade for 60 min. 2. Heart rate (HR) was recorded at rest and during exercise, 15% grade at 0.5, 0.8 and 1.0 mph, for 3 min per stage. Vagal and sympathetic effects were studied after the administration of methylatropine (3 mg/kg) and propranolol (4 mg/kg). 3. Exercise training significantly attenuated cardiac acceleration at 0.8 (441 +/- 8 vs 486 +/- 9 bpm in S, P < 0.05) and 1.0 mph (466 +/- 12 vs 508 +/- 6 bpm in S, P < 0.05). The vagal effect was significantly increased in the T group at 0.8 (72 +/- 5 vs 32 +/- 10 bpm in S, P < 0.05) and 1.0 mph (46 +/- 8 vs 15 +/- 7 bpm in S, P < 0.05). The sympathetic effect was significantly decreased in the T group at 0.8 (73 +/- 9 vs 112 +/- 9 bpm in S, P < 0.05) and 1.0 mph (96 +/- 11 vs 125 +/- 7 bpm in S, P < 0.05). The intrinsic HR behavior was not different between groups.(ABSTRACT TRUNCATED AT 250 WORDS)
Search on Google
Index:
LILACS (Americas)
Main subject:
Physical Conditioning, Animal
/
Sympathetic Nervous System
/
Vagus Nerve
/
Heart
/
Heart Rate
Limits:
Animals
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
1992
Type:
Article
Similar
MEDLINE
...
LILACS
LIS