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This Article Full Text Full Text (PDF) All Versions of this Article: 297/4/H1462    most recent 00442.2009v1 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 Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Jobe, L. J. Articles by Janicki, J. S. PubMed PubMed Citation Articles by Jobe, L. J. Articles by Janicki, J. S.

TNF- inhibition attenuates adverse myocardial remodeling in a rat model of volume overload

Department of Cell Biology and Anatomy, School of Medicine, University of South Carolina, Columbia, South Carolina

Submitted May 13, 2009 ; accepted in final form August 4, 2009

Tumor necrosis factor (TNF)- is a proinflammatory cytokine that has been implicated in the pathogenesis of heart failure. In contrast, we have recently shown that myocardial levels of TNF- are acutely elevated in the aortocaval (AV) fistula model of heart failure. Based on these observations, we hypothesized that progression of adverse myocardial remodeling secondary to volume overload would be prevented by inhibition of TNF- with etanercept. Furthermore, a principal objective of this study was to elucidate the effect of TNF- inhibition during different phases of the myocardial remodeling process. Eight-week-old male Sprague-Dawley rats were randomly divided into the following three groups: sham-operated controls, untreated AV fistulas, and etanercept-treated AV fistulas. Each group was further subdivided to study three different time points consisting of 3 days, 3 wk, and 8 wk postfistula. Etanercept was administered subcutaneously at 1 mg/kg body wt. Etanercept prevented collagen degradation at 3 days and significantly attenuated the decrease in collagen at 8 wk postfistula. Although TNF- antagonism did not prevent the initial ventricular dilatation at 3 wk postfistula, etanercept was effective at significantly attenuating the subsequent ventricular hypertrophy, dilatation, and increased compliance at 8 wk postfistula. These positive adaptations achieved with etanercept administration translated into significant functional improvements. At a cellular level, etanercept also markedly attenuated increases in cardiomyocyte length, width, and area at 8 wk postfistula. These observations demonstrate that TNF- has a pivotal role in adverse myocardial remodeling and that treatment with etanercept can attenuate the progression to heart failure.

diastolic function; intrinsic contractility; myocyte dimensions; etanercept; extracellular matrix; ventricular pressure-volume relationship