ISSN:
1439-6327
Keywords:
Exercise
;
Triglycerides
;
Free fatty acids
;
Glycerol
;
Insulin
;
Catecholamines
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Metabolic and hormonal responses to prolonged treadmill exercise in dogs fed a fat-enriched meal 4 h prior to the exercise were compared to those measured 4 h after a mixed meal or in the postabsorptive state. Ingestion of the fat-enriched meal caused significant elevations in the resting values of plasma triglyceride (TG), free fatty acid (FFA), and glycerol concentrations. A reduction of the plasma TG concentration (from 1.6±0.2 to 1.1±0.10 mmol·l−1,P〈0.005) occurred only in dogs exercising after the fat-enriched meal. No significant changes in this variable were noted in dogs fed a mixed meal, whilst in the postabsorptive state exercise caused an increase in the plasma TG level (from 0.42±0.03 to 0.99±0.11 mmol·l−1,P〈0.01). The exercise-induced elevations in plasma FFA and glycerol concentrations were the highest in the dogs given the fat-enriched meal. Plasma glycerol during exercise correlated with the initial values of circulating TG (r=0.73). The plasma FFA-glycerol ratio, at the end of exercise was lowest in the dogs taking the fat-enriched meal (1.39±0.19), suggesting an increased utilization of FFA in comparison with that in the postabsorptive state (3.27±0.37) or after a mixed meal (2.88±0.55). Basal serum insulin (IRI) concentrations were similarly enhanced in dogs fed fat-enriched and mixed meals, and they were reduced to control values within 60 min of exercise. Plasma adrenaline and noradrenaline concentrations correlated with time of exercise (r=0.84 andr=0.96, respectively) and were unaffected by the nutritional modifications. It is concluded that ingestion of a single fat-enriched meal considerably modifies the exercise-induced changes in lipid metabolism. The pattern of changes in plasma TG, FFA, and glycerol concentrations indicates an enhanced hydrolysis of plasma chylomicron-TG, suggesting that this lipid source may contribute markedly to exercise metabolism.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00776601
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