HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 103/5/1757    most recent 00487.2007v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Behnke, B. J. Articles by Musch, T. I. Search for Related Content PubMed PubMed Citation Articles by Behnke, B. J. Articles by Musch, T. I.

Aging potentiates the effect of congestive heart failure on muscle microvascular oxygenation

¹Division of Exercise Physiology, and the Center for Interdisciplinary Research in Cardiovascular Sciences, West Virginia University School of Medicine, Morgantown, West Virginia; and ²Departments of Anatomy, Physiology and Kinesiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas

Submitted 4 May 2007 ; accepted in final form 27 August 2007

Congestive heart failure (CHF) is most prevalent in aged individuals and elicits a spectrum of cardiovascular and muscular perturbations that impairs the ability to deliver (O₂) and utilize (O₂) oxygen in skeletal muscle. Whether aging potentiates the CHF-induced alterations in the O₂-to-O₂ relationship [which determines microvascular PO₂ (Pmv_O2)] in resting and contracting skeletal muscle is unclear. We tested the hypothesis that old rats with CHF would demonstrate a greater impairment of skeletal muscle Pmv_O2 than observed in young rats with CHF. Phosphorescence quenching was utilized to measure spinotrapezius Pmv_O2 at rest and across the rest-to-contractions (1-Hz, 4–6 V) transition in young (Y) and old (O) male Fischer 344 Brown-Norway rats with CHF induced by myocardial infarction (mean left ventricular end-diastolic pressure >20 mmHg for Y_CHF and O_CHF). In CHF muscle, aging significantly reduced resting Pmv_O2 (32.3 ± 3.4 Torr for Y_CHF and 21.3 ± 3.3 Torr for O_CHF; P < 0.05) and in both Y_CHF and O_CHF compared with their aged-matched counterparts, CHF reduced the rate of the Pmv_O2 fall at the onset of contractions. Moreover, across the on-transient and in the subsequent steady state, Pmv_O2 values in O_CHF vs. Y_CHF were substantially lower (for steady-state, 20.4 ± 1.7 Torr for Y_CHF and 16.4 ± 2.0 Torr for O_CHF; P < 0.05). At rest and during contractions in CHF, the pressure driving blood-muscle O₂ diffusion (Pmv_O2) is substantially decreased in old animals. This finding suggests that muscle dysfunction and exercise intolerance in aged CHF patients might be due, in part, to the failure to maintain a sufficiently high Pmv_O2 to facilitate blood-muscle O₂ exchange and support mitochondrial ATP production.

heart failure; skeletal muscle; oxygen exchange

This article has been cited by other articles:

				G. R. Chiappa, A. Borghi-Silva, L. F. Ferreira, C. Carrascosa, C. C. Oliveira, J. Maia, A. C. Gimenes, F. Queiroga Jr, D. Berton, E. M. V. Ferreira, et al. Kinetics of muscle deoxygenation are accelerated at the onset of heavy-intensity exercise in patients with COPD: relationship to central cardiovascular dynamics J Appl Physiol, May 1, 2008; 104(5): 1341 - 1350. [Abstract] [Full Text] [PDF]