Reduced collagen accumulation and augmented MMP-2 activity in left ventricle of old rats submitted to high-intensity resistance training.

Autor:	Guzzoni V; Department of Physiological Sciences, Federal University of São Carlos, São Carlos, Brazil; vinicius.guzzoni@gmail.com., Marqueti RC; Physiotherapy Division, University of Brasilia, Brasilia, Brazil., Durigan JLQ; Physiotherapy Division, University of Brasilia, Brasilia, Brazil., Faustino de Carvalho H; Institute of Biology, State University of Campinas, Campinas, Brazil., Lino RLB; Department of Physiological Sciences, Federal University of São Carlos, São Carlos, Brazil., Mekaro MS; Department of Physiological Sciences, Federal University of São Carlos, São Carlos, Brazil., Costa Santos TO; Department of Physiological Sciences, Federal University of São Carlos, São Carlos, Brazil., Mecawi AS; Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil; and., Rodrigues JA; Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil; and., Hord JM; Department of Health & Kinesiology, Texas A&M University, College Station, Texas., Lawler JM; Department of Health & Kinesiology, Texas A&M University, College Station, Texas., Davel AP; Institute of Biology, State University of Campinas, Campinas, Brazil., Selistre-de-Araújo HS; Department of Physiological Sciences, Federal University of São Carlos, São Carlos, Brazil.
Jazyk:	angličtina
Zdroj:	Journal of applied physiology (Bethesda, Md. : 1985) [J Appl Physiol (1985)] 2017 Sep 01; Vol. 123 (3), pp. 655-663. Date of Electronic Publication: 2017 Jul 06.
DOI:	10.1152/japplphysiol.01090.2016
Abstrakt:	Progressive fibrosis is a hallmark of the aging heart. Age-related fibrosis is modulated by endurance exercise training; however, little is known concerning the influence of resistance training (RT). Therefore we investigated the chronic effects of high-intensity RT on age-associated alterations of left ventricle (LV) structure, collagen content, matrix metalloproteinase-2 (MMP-2), and extracellular matrix-related gene expression, including transforming growth factor-β (TGF-β). Young adult (3 mo) and aged (21 mo) male Wistar rats were submitted to a RT protocol (ladder climbing with 65, 85, 95, and 100% load), three times a week for 12 wk. Forty-eight hours posttraining, arterial systolic and diastolic pressure, LV end-diastolic pressure (LVEDP) and dP/d t were recorded. LV morphology, collagen deposition, and gene expression of type I (COL-I) and type III (COL-III) collagen, MMP-2, tissue inhibitor of metalloproteinases-1 (TIMP-1), and TGF-β1 were analyzed by quantitative reverse transcriptase-PCR. MMP-2 content was assessed by zymography. Increased collagen deposition was observed in LV from aged rats. These parameters were modulated by RT and were associated with increased MMP-2 activity and decreased COL-I, TGF-β1, and TIMP-1 mRNA content. Despite the effect of RT on collagen accumulation, there was no improvement on LVEDP and maximal negative LV dP/d t of aged rats. Cardiomyocyte diameter was preserved in all experimental conditions. In conclusion, RT attenuated age-associated collagen accumulation, concomitant to the increase in MMP-2 activity and decreased expression of COL-I, TGF-β1, and TIMP-1 in LV, illustrating a cardioprotective effect of RT on ventricular structure and function. NEW & NOTEWORTHY We demonstrated the beneficial resistance-training effect against age-related left ventricle collagen accumulation in the left ventricle, which was associated with decreased type I collagen (COL-I), transforming growth factor-β1 (TGF-β1), and tissue inhibitor of metalloproteinases-1 (TIMP-1) gene expression and matrix metalloproteinase-2 (MMP-2) activity. Our findings suggest for the first time the potential effects of resistance training in modulating collagen accumulation and possibly fibrosis in the aging heart. (Copyright © 2017 the American Physiological Society.)
Databáze:	MEDLINE
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