ISSN:
1432-2013
Keywords:
Male rats
;
Fibre type distribution
;
Food restriction
;
Fast and slow-twitch skeletal muscles
;
Oxidative and glycolytic enzymes
;
Physical training
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The aim of this study was to determine the impact of chronic treatment for 8 weeks with hydrocortisone acetate (5 mg kg−1 day−1) on skeletal muscles, and to evaluate whether sprint training can prevent glucocorticoid-induced muscle atrophy better than endurance training. Biochemical, histological and contractile properties were employed to determine the influence of this steroid on skeletal musculature, and the results were compared to pair-weight animals to take into account the influence of corticoids on growth rate. It was found that hydrocortisone acetate treatment results in a stunted growth, adrenal atrophy and depressed plasma corticosterone levels. Mild corticoid-induced losses of muscle mass and protein content (9%–13%) were observed in fast-twitch skeletal muscles. It appeared that the impact of corticoids is strictly directed toward type IIb fibres, which displayed a 12%–18% reduction in cross-sectional areas. No alterations occurred in plantaris contractile speed or tensions properties. Neither endurance training (30 m/min; 90 min/day; 5 days/week) nor sprint training (60 m/min; 15 min/day; 5 days/week) for 8 weeks was able to counteract the effects of corticoids. These data suggest that increased contractile activity, as induced by treadmill running, is not sufficient to counteract the muscular effects of glucocorticoids when administered at a dose of 5 mg kg−1 day−1.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00374896
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