Metabolic and hormonal responses to prolonged physical exercise in dogs after a single fat-enriched meal.
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 X l-1, P less than 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 X l-1, P less than 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.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D004041:Dietary Fats / Q000494:pharmacology*; D004285:Dogs; D004837:Epinephrine / Q000097:blood; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005990:Glycerol / Q000097:blood; D006728:Hormones / Q000502:physiology*; D007328:Insulin / Q000097:blood; D007773:Lactates / Q000097:blood; D008297:Male; D008660:Metabolism / Q000187:drug effects*; D009638:Norepinephrine / Q000097:blood; D005082:Physical Exertion; D013997:Time Factors; D014280:Triglycerides / Q000097:blood*
D001786:Blood Glucose; D004041:Dietary Fats; D005230:Fatty Acids, Nonesterified; D006728:Hormones; D007328:Insulin; D007773:Lactates; D014280:Triglycerides; D005990:Glycerol; D009638:Norepinephrine; D004837:Epinephrine