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Int J Sports Med 2015; 36(05): 343-350
DOI: 10.1055/s-0034-1395585
Physiology & Biochemistry
© Georg Thieme Verlag KG Stuttgart · New York

Regulation of mTOR Pathway in Exercise-induced Cardiac Hypertrophy

J. Liao
1   Department of Sport Science, Beijing Sport University, Beijing, China
,
Y. Li
2   Department of Sport, Jianghan University, Wuhan, China
,
F. Zeng
1   Department of Sport Science, Beijing Sport University, Beijing, China
,
Y. Wu
1   Department of Sport Science, Beijing Sport University, Beijing, China
› Author Affiliations
Further Information

Publication History



accepted after revision 09 September 2014

Publication Date:
21 January 2015 (online)

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Abstract

This study was designed to examine whether the mTOR signaling pathway would respond to long-term different intensity exercises and to observe the impact of exercise upon possible cardiac damage. Male Sprague Dawley rats were randomly divided into control group, moderate-intensity exercise group and high-intensity exercise group, and each exercise group had 4 observation time points (1–24 h). Exercise training lasted 8 weeks with a 2-day break for each week. Serum cTnI was measured by ELSIA and myocardium histology was assessed by HE and HBFP. The expressions of Akt, mTOR, p70S6K and their phosphorylated forms were determined by western-blot. Both exercises were effective at inducing cardiac hypertrophy, wherein magnitude increased with exercise intensity. The significantly high level of serum cTnI in the high-intensity group was accompanied by obvious myocellular abnormalities and ischemia in the myocardium. Significant activation of Akt, mTOR and p70S6K were observed in the moderate exercise group but not in the high-intensity exercise group. Results indicate that long-term high-intensity exercise training would induce cardiac hypertrophy accompanied by damage to the heart, entailing a risk of pathological changes. There might be a pivotal regulatory role of the mTOR signaling pathway on cardiac hypertrophy after long-term moderate exercise, but not after high-intensity exercise.

Key words

mammalian target of rapamycin - cardiac hypertrophy - exercises - signaling transduction
 

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