title: Prolonged exercise training induces long-term enhancement of HSP70 expression in rat plantaris muscle.
abstract: 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 degrees grade) or prolonged treadmill running training (15-40 m/min, 5 min x 4, 5-7 degrees 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.
authors.affiliation: Faculty of Sport Sciences, Waseda University, Saitama, Japan. ogata@aoni.waseda.jp
authors.forename: Tomonori
authors.initials: T
authors.lastname: Ogata
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Oishi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Higashida
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Higuchi
authors.forename: Isao
authors.initials: I
authors.lastname: Muraoka
mesh_terms: D000818:Animals; D001835:Body Weight / Q000502:physiology; D018834:Chaperonin 60 / Q000378:metabolism; D050883:HSC70 Heat-Shock Proteins / Q000378:metabolism; D055551:HSP27 Heat-Shock Proteins / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000378:metabolism; D008297:Male; D023421:Models, Animal; D018832:Molecular Chaperones / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D000091342:Endoplasmic Reticulum Chaperone BiP
chemical_list: D018834:Chaperonin 60; D050883:HSC70 Heat-Shock Proteins; D055551:HSP27 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D012333:RNA, Messenger; C051684:GRP78 protein, rat; D000091342:Endoplasmic Reticulum Chaperone BiP; C494373:Hspa8 protein, rat; C486114:Hspb1 protein, rat