Bowen, TS, Eisenkolb, S, Drobner, J et al. (6 more authors) (2017) High-intensity interval training prevents oxidant-mediated diaphragm muscle weakness in hypertensive mice. The FASEB Journal, 31 (1). pp. 60-71. ISSN 0892-6638
Abstract
Hypertension is a key risk factor for heart failure, with the latter characterized by diaphragm muscle weakness that is mediated in part by increased oxidative stress. In the present study, we used a deoxycorticosterone acetate (DOCA)-salt mouse model to determine whether hypertension could independently induce diaphragm dysfunction and further investigated the effects of high-intensity interval training (HIIT). Sham-treated (n = 11), DOCA-salt-treated (n = 11), and DOCA-salt+HIIT-treated (n = 15) mice were studied over 4 wk. Diaphragm contractile function, protein expression, enzyme activity, and fiber cross-sectional area and type were subsequently determined. Elevated blood pressure confirmed hypertension in DOCA-salt mice independent of HIIT (P < 0.05). Diaphragm forces were impaired by ∼15–20% in DOCA-salt vs. sham-treated mice (P < 0.05), but this effect was prevented after HIIT. Myosin heavy chain (MyHC) protein expression tended to decrease (∼30%; P = 0.06) in DOCA-salt vs. sham- and DOCA-salt+HIIT mice, whereas oxidative stress increased (P < 0.05). Enzyme activity of NADPH oxidase was higher, but superoxide dismutase was lower, with MyHC oxidation elevated by ∼50%. HIIT further prevented direct oxidant-mediated diaphragm contractile dysfunction (P < 0.05) after a 30 min exposure to H₂O₂ (1 mM). Our data suggest that hypertension induces diaphragm contractile dysfunction via an oxidant-mediated mechanism that is prevented by HIIT.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Keywords: | skeletal muscle; exercise; heart failure |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Biomedical Sciences (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 02 Nov 2017 14:27 |
Last Modified: | 02 Nov 2017 14:31 |
Status: | Published |
Publisher: | Federation of American Society of Experimental Biology |
Identification Number: | 10.1096/fj.201600672R |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:123398 |