| Autor: |
Russell, Aaron P., Feilchenfeldt, Jonas, Meier, Christoph A., Schreiber, Sylvia, Praz, Manu, Crettenand, Antoinette, Gobelet, Charles, Dériaz, Olivier, Bell, David R., Kralli, Anastasia, Giacobino, Jean-Paul, Dériaz, Olivier |
| Předmět: |
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| Zdroj: |
Diabetes; Dec2003, Vol. 52 Issue 12, p2874-2881, 8p, 1 Color Photograph, 1 Black and White Photograph, 2 Charts, 3 Graphs |
| Abstrakt: |
The peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1 (PGC-1) can induce mitochondria biogenesis and has been implicated in the development of oxidative type I muscle fibers. The PPAR isoforms α, β/δ, and γ control the transcription of genes involved in fatty acid and glucose metabolism. As endurance training increases skeletal muscle mitochondria and type I fiber content and fatty acid oxidative capacity, our aim was to determine whether these increases could be mediated by possible effects on PGC-1 or PPAR-α, -β/δ, and -γ. Seven healthy men performed 6 weeks of endurance training and the expression levels of PGC-1 and PPAR-α, -β/δ, and -γ mRNA as well as the fiber type distribution of the PGC-1 and PPAR-α proteins were measured in biopsies from their vastus lateralis muscle. PGC-1 and PPAR-α mRNA expression increased by 2.7- and 2.2-fold (P < 0.01), respectively, after endurance training. PGC-1 expression was 2.2- and 6-fold greater in the type IIa than in the type I and Iix fibers, respectively. It increased by 2.8-fold in the type IIa fibers and by 1.5-fold in both the type I and Iix fibers after endurance training (P < 0.015). PPAR-α was 1.9-fold greater in type I than in the II fibers and increased by 3.0-fold and 1.5-fold in these respective fibers after endurance training (P < 0.001). The increases in PGC-1 and PPAR-α levels reported in this study may play an important role in the changes in muscle mitochondria content, oxidative phenotype, and sensitivity to insulin known to be induced by endurance training. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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