Klabunde R E, Laughlin M H, Armstrong R B
Department of Physiology, West Virginia University Medical Center, Morgantown 26506.
J Appl Physiol (1985). 1988 Jan;64(1):108-14. doi: 10.1152/jappl.1988.64.1.108.
The importance of adenosine in controlling the magnitude and distribution of blood flow among and within skeletal muscles in rats during slow locomotor exercise was tested by systemic infusion of adenosine deaminase (ADA). Blood flows were measured using labeled microspheres before exercise and at 0.5, 15, and 30 min of fast treadmill walking at 15 m/min. An initial infusion of ADA (1,000 U/kg) was given 30 min before the first blood flow measurement and a second injection (1,000 U/kg) was given 5 min into exercise. These infusions maintained ADA activity above 5 U/ml blood throughout the experimental period. This plasma concentration of ADA was shown to be sufficient to result in a 64% decrease in muscle adenosine levels during ischemic contraction. Blood flows were measured in all of the muscles of the hindlimb (28 samples) and in various nonmuscular tissues in ADA-treated and control rats. Preexercise blood flows were primarily directed to slow-twitch muscles and exercise blood flows were highest in muscles with fast-twitch oxidative fibers. ADA treatment did not reduce total muscle blood flow or exercise blood flows in any of the muscles at any time. These findings do not support the hypothesis that adenosine plays an essential role in controlling muscle blood flow in skeletal muscles during normal locomotor activity.
通过全身输注腺苷脱氨酶（ADA）来测试腺苷在慢速运动期间控制大鼠骨骼肌间及肌内血流大小和分布的重要性。在运动前以及以15米/分钟的速度在快速跑步机上行走0.5、15和30分钟时，使用标记微球测量血流。在首次血流测量前30分钟给予初始剂量的ADA（1000 U/kg），并在运动开始5分钟时给予第二次注射（1000 U/kg）。这些输注在整个实验期间将ADA活性维持在血液5 U/ml以上。已证明这种血浆ADA浓度足以使缺血性收缩期间肌肉腺苷水平降低64%。在接受ADA治疗的大鼠和对照大鼠中，测量了后肢所有肌肉（28个样本）以及各种非肌肉组织中的血流。运动前血流主要流向慢肌纤维，而运动期间血流在具有快肌氧化纤维的肌肉中最高。ADA治疗在任何时候都没有降低任何肌肉的总肌肉血流量或运动期间的血流。这些发现不支持腺苷在正常运动活动期间控制骨骼肌血流中起重要作用这一假设。
