| Autor: |
Horton, Tracy J., Commerford, S. Renee, Pagliassotti, Michael J., Bessesen, Daniel H. |
| Předmět: |
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| Zdroj: |
American Journal of Physiology: Endocrinology & Metabolism; Dec2002, Vol. 46 Issue 6, pE1192, 11p, 1 Diagram, 3 Charts, 14 Graphs |
| Abstrakt: |
s The postprandial excursion of plasma triglyceride (TG) concentration is greater in men than in women. In this study, the disposition of dietary fat was examined in lean healthy men and women (n = 8/group) in either the overnight-fasted or fed (4.5 h after breakfast) states. A [[sup 14]C]oleate tracer was incorporated into a test meal, providing 30% of total daily energy requirements. After ingestion of the test meal, measures of arteriovenous differences in TG and [sup 14]C across the leg were combined with needle biopsies of skeletal muscle and adipose tissue and respiratory gas collections to define the role of skeletal muscle in the clearance of dietary fat. The postprandial plasma TG and [sup 14]C tracer excursions were lower (P = 0.04) in women than in men in the overnight-fasted and fed states. Women, however, had significantly greater limb uptake of total TG compared with men on both the fasted (3,849 ± 846 vs. 528 ± 221 total µmol over 6 h) and fed (4,847 ± 979 vs. 1,571 ± 334 total µmol over 6 h) days. This was also true for meal-derived [sup 14]C lipid uptake. [sup 14]C content of skeletal muscle tissue (µCi/g tissue) was significantly greater in women than in men 6 h after ingestion of the test meal. In contrast, [sup 14]C content of adipose tissue was not significantly different between men and women at 6 h. The main effect of nutritional state, fed vs. fasted, was to increase the postmeal glucose (P = 0.01) excursion (increase from baseline) and decrease the postmeal TG excursion (P = 0.02). These results support the notion that enhanced skeletal muscle clearance of lipoprotein TG in women contributes to their reduced postprandial TG excursion. Questions remain as to the mechanisms causing these sex-based differences in skeletal muscle TG uptake and metabolism. Furthermore, nutritional state can significantly impact postprandial metabolism in both men and women. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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