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This Article Full Text Full Text (PDF) All Versions of this Article: 296/5/R1557    most recent 90911.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ogata, T. Articles by Muraoka, I. Search for Related Content PubMed PubMed Citation Articles by Ogata, T. Articles by Muraoka, I.

EXERCISE AND RESPIRATORY PHYSIOLOGY

Prolonged exercise training induces long-term enhancement of HSP70 expression in rat plantaris muscle

¹Faculty of Sport Sciences, Waseda University, Saitama; ²Faculty of Education, Kumamoto University, Kumamoto; and ³Graduate School of Sport Sciences, Waseda University, Saitama, Japan

Submitted 10 November 2008 ; accepted in final form 19 February 2009

Skeletal muscle may develop adaptive molecular chaperone enhancements as a potential defense system through repeated daily exercise stimulation. The present study investigated whether prolonged exercise training alters the expression of molecular chaperone proteins for the long term in skeletal muscle. Mature male Wistar rats were subjected for 8 wk to either a single bout of acute intermittent treadmill running (30 m/min, 5 min x 4, 5° grade) or prolonged treadmill running training (15–40 m/min, 5 min x 4, 5–7° grade). Levels of five molecular chaperone proteins [heat shock protein (HSP)25, HSP60, glucose-regulated protein (GRP)78, HSP70, and heat shock cognate (HSC)70] were measured in response to acute exercise and prolonged training. HSP70 levels were increased 6 and 24 h after acute exercise, but expression returned to control level within 2 days. In contrast, prolonged training had a long-term effect on HSP70 expression. Levels of HSP70 were notably increased by 4.5-fold over control 2 days after prolonged training; the enhancement was maintained for at least 14 days after training ended. However, other molecular chaperone proteins did not show adaptive changes in response to prolonged training. In addition, HSP70 enhancement by prolonged exercise training was not accompanied by transcription of HSP70 mRNA. These findings demonstrate that prolonged training can induce long-term enhancement of HSP70 expression without change at the mRNA level in skeletal muscle.

molecular chaperone; heat shock protein 70; adaptation; skeletal muscle