Ferguson Scott K, Holdsworth Clark T, Colburn Trenton D, Wright Jennifer L, Craig Jesse C, Fees Alex, Jones Andrew M, Allen Jason D, Musch Timothy I, Poole David C
Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas; Cardiovascular and Pulmonary Research Laboratory, Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado.
Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas;
J Appl Physiol (1985). 2016 Sep 1;121(3):661-9. doi: 10.1152/japplphysiol.00014.2016. Epub 2016 Jul 21.
Chronic heart failure (CHF) results in central and peripheral derangements that ultimately reduce skeletal muscle O2 delivery and impair exercise tolerance. Dietary nitrate (NO3 (-)) supplementation improves skeletal muscle vascular function and tolerance to exercise. We tested the hypothesis that NO3 (-) 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 5 days of NO3 (-)-rich beetroot juice (CHF + BR, n = 10) or a placebo (CHF, n = 10). Mean arterial pressure (carotid artery catheter) and skeletal muscle BF (radiolabeled microspheres) were measured during treadmill exercise (20 m/min, 5% grade). CHF-induced dysfunction, as determined by myocardial infarction size (29 ± 3% and 33 ± 4% in CHF and CHF + BR, respectively) and left ventricular end-diastolic pressure (18 ± 2 and 18 ± 2 mmHg in CHF and CHF + BR, respectively), and exercising mean arterial pressure (131 ± 3 and 128 ± 4 mmHg in CHF and CHF + BR, respectively) were not different (P > 0.05) between groups. Total exercising hindlimb skeletal muscle BF (95 ± 5 and 116 ± 9 ml·min(-1)·100 g(-1) in CHF and CHF + BR, respectively) and VC (0.75 ± 0.05 and 0.90 ± 0.05 ml·min(-1)·100 g(-1)·mmHg(-1) in CHF and CHF + BR, respectively) were 22% and 20% greater in BR-supplemented rats, respectively (P < 0.05). During exercise, BF in 9 and VC in 10 hindlimb muscles and muscle portions were significantly greater in the CHF + BR group. These results provide strong evidence that dietary NO3 (-) supplementation improves skeletal muscle vascular function during exercise in rats with CHF and, thus, support the use of BR as a novel therapeutic modality for the treatment of CHF.
慢性心力衰竭（CHF）会导致中枢和外周功能紊乱，最终减少骨骼肌的氧气供应并损害运动耐力。补充膳食硝酸盐（NO3 (-)）可改善骨骼肌血管功能和运动耐力。我们检验了以下假设：补充NO3 (-)会提高CHF大鼠运动时的骨骼肌血流量（BF）和血管传导率（VC）。在年轻成年雄性大鼠中诱导心肌梗死（MI）（冠状动脉结扎）。恢复21天后，大鼠随机接受5天富含NO3 (-)的甜菜根汁（CHF + BR，n = 10）或安慰剂（CHF，n = 10）。在跑步机运动（20米/分钟，坡度5%）期间测量平均动脉压（颈动脉导管）和骨骼肌BF（放射性微球）。CHF诱导的功能障碍，通过心肌梗死面积（CHF和CHF + BR组分别为29 ± 3%和33 ± 4%）和左心室舒张末期压力（CHF和CHF + BR组分别为18 ± 2和18 ± 2 mmHg）确定，以及运动时的平均动脉压（CHF和CHF + BR组分别为131 ± 3和128 ± 4 mmHg）在两组之间无差异（P > 0.05）。总运动后肢骨骼肌BF（CHF和CHF + BR组分别为95 ± 5和116 ± 9毫升·分钟(-1)·100克(-1)）和VC（CHF和CHF + BR组分别为0.75 ± 0.05和0.90 ± 0.05毫升·分钟(-1)·100克(-1)·毫米汞柱(-1)）在补充甜菜根汁的大鼠中分别高出22%和20%（P < 0.05）。运动期间，CHF + BR组9块后肢肌肉和10块肌肉部分的BF以及VC显著更高。这些结果提供了有力证据，表明补充膳食NO3 (-)可改善CHF大鼠运动期间的骨骼肌血管功能，因此，支持将甜菜根汁用作治疗CHF的新型治疗方式。
