Beta-endorphin infusion during exercise in rats does not alter hepatic or muscle glycogen
Deutscher übersetzter Titel: | Keine Veränderung des Leber- oder Muskelglykogens durch Beta-Endorphin-Infusionen während des Trainings bei Ratten |
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Autor: | Jamurtas, Athanasios Z.; Goldfarb, Allan H.; Chung, Shiow-Chin; Hedge, Sudhir; Marino, Chris; Fatouros, Ioannis G. |
Erschienen in: | Journal of sports sciences |
Veröffentlicht: | 19 (2001), 12, S. 931-935, Lit. |
Format: | Literatur (SPOLIT) |
Publikationstyp: | Zeitschriftenartikel |
Medienart: | Gedruckte Ressource |
Sprache: | Englisch |
ISSN: | 0264-0414, 1466-447X |
Schlagworte: | |
Online Zugang: | |
Erfassungsnummer: | PU200909004086 |
Quelle: | BISp |
Abstract
The aim of this study was to determine whether β-endorphin infusion influences liver or muscle glycogen concentration during exercise. Thirty-two rats (Harlan Co., IN, USA) with a body mass of 265-290 g were assigned at random to four groups, each of eight rats: (1) β-endorphin infusion for 90 min at rest; (2) β-endorphin infusion for 90 min while running on a rodent treadmill at 22 m/min and 0% grade; (3) saline infusion (0.9% NaCl) for 90 min at rest; and (4) saline infusion for 90 min while running on a rodent treadmill at 22 m/min and 0% grade. Beta-endorphin infusion elevated plasma β-endorphin concentration by 2.5-fold at rest compared with saline infusion at rest, and by two-fold after exercise compared with saline infusion after exercise. Beta-endorphin infusion attenuated exercise-induced glucose concentration but did not alter the fasting hepatic glycogen concentration at rest or after exercise compared with saline infusion. Fasting hepatic glycogen decreased significantly as a result of 90 min of exercise independent of treatment. Deep intermedius muscle glycogen concentration at rest was similar after 90 min of both β-endorphin and saline infusion and decreased significantly as a result of 90 min of exercise independent of treatment. Our results suggest that liver and muscle glycogenolysis is not responsible for the differences in plasma glucose with β-endorphin infusion during exercise. Verf.-Referat