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Chronic heart failure and nitrate supplementation: Impact on skeletal muscle vascular control in exercising rats
Author(s) -
Ferguson Scott,
Holdsworth Clark,
Wright Jennifer,
Hageman Karen,
Musch Timothy,
Poole David
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.1055.25
Subject(s) - skeletal muscle , heart failure , medicine , preload , cardiology , vasodilation , endocrinology , hemodynamics
Chronic heart failure (CHF) results in central and peripheral derangements that ultimately reduce skeletal muscle O 2 delivery and impair exercise tolerance. Dietary nitrate (NO 3 ‐ ) supplementation improves skeletal muscle vascular function and improves tolerance to exercise. We tested the hypothesis that NO 3 ‐ supplementation would elevate exercising skeletal muscle blood flow (BF) and vascular conductance (VC) in CHF rats. Myocardial infarction (MI) was induced (coronary artery ligation) in young‐adult male rats. After 21‐days of recovery, rats randomly received NO 3 ‐ rich beetroot juice (CHF+BR, n=10) or a placebo (CHF, n=10). Mean arterial pressure (MAP, carotid artery catheter) and skeletal muscle BF (radiolabeled microspheres) was measured during treadmill exercise (20 m/min, 5% grade). CHF parameters (MI size, CHF: 29 ± 3, CHF+BR: 33 ± 4%, LVEDP, CHF: 18 ± 2, CHF+BR: 18 ± 2 mmHg) and exercising MAP (CHF: 131 ± 3, CHF +BR: 128 ± 4 mmHg) were not different (P<0.05) between groups. Total hindlimb skeletal muscle BF (CHF: 95 ± 5, CHF+BR: 116 ± 9 ml/min/100g) and VC (CHF: 0.75 ± 0.05, CHF+BR: 0.90 ± 0.05) were greater (P<0.05) in BR supplemented rats. The increases in BF and VC (P<0.05) were found preferentially in muscles and muscle parts containing 蠅70% type IIb + d/x muscle fibers which resulted in a ~22% increase in total skeletal muscle BF and a 20% increase in total VC during exercise. These results provide strong evidence that dietary NO 3 ‐ supplementation improves skeletal muscle vascular function during exercise in rats with CHF and suggest that BR may provide a novel therapeutic modality for the treatment of CHF.
NIH HL‐108328