Sexton W L
Department of Physiology, Kirksville College of Osteopathic Medicine, Missouri 63501, USA.
J Appl Physiol (1985). 1995 Jul;79(1):287-96. doi: 10.1152/jappl.1995.79.1.287.
To test the hypothesis that voluntary running-wheel exercise would elicit vascular adaptations in rat skeletal muscle, male Sprague-Dawley rats (202 +/- 5 g) were cage confined (C, n = 11) or housed in cages with free access to running wheels (R, n = 13) for 12 wk. Vascular transport capacity was determined in maximally vasodilated (papaverine) hindquarters of C and R rats with measurements of total and regional (radiolabeled microspheres) flow capacity and capillary filtration coefficient. R rats voluntarily ran 29 +/- 4 km/wk over the 12-wk period; however, performance of individual rats varied greatly (range 4-74 km/wk). Citrate synthase activity was increased in the medial head (81%, P < 0.001) and the red long head (88%, P < 0.001) of the triceps brachii muscle in R rats but not in the white long head (25%, P = 0.06). Capillary filtration coefficient was 27% greater in R compared with C rats (0.040 +/- 0.003 vs. 0.031 +/- 0.002 ml.min-1.100 g-1.mmHg-1, respectively, P < 0.001) suggesting that there was an increase in microvascular surface area available for fluid exchange. Total hindquarters flow was increased in R rats (P < 0.05) at all perfusion pressures examined, indicative of an increased flow capacity. Regional flows revealed that skin flow was unchanged in R rats and that the increase in total flow was due to increased skeletal muscle flow capacity. These results indicate that voluntary running-wheel exercise elicits adaptive increases in skeletal muscle vascular transport capacity and oxidative capacity comparable to those seen in treadmill-trained rats and support the use of voluntary running-wheel exercise as a less stressful training modality in exercise studies using rats.
为了验证自愿性跑轮运动是否会引起大鼠骨骼肌血管适应性变化这一假设，将雄性Sprague-Dawley大鼠（体重202±5 g）分为两组，一组关在笼中饲养（C组，n = 11），另一组饲养在可自由使用跑轮的笼子里（R组，n = 13），为期12周。通过测量最大血管舒张（罂粟碱作用下）后肢的总血流量和局部血流量（放射性微球法）以及毛细血管滤过系数，来确定血管运输能力。R组大鼠在12周内自愿跑了29±4 km/周；然而，个体大鼠的跑量差异很大（范围为4 - 74 km/周）。R组大鼠肱三头肌内侧头（增加81%，P < 0.001）和红色长头（增加88%，P < 0.001）的柠檬酸合酶活性升高，但白色长头未升高（增加25%，P = 0.06）。与C组大鼠相比，R组大鼠的毛细血管滤过系数高27%（分别为0.040±0.003和0.031±0.002 ml·min-1·100 g-1·mmHg-1，P < 0.001），这表明可用于液体交换的微血管表面积增加。在所有检测的灌注压力下，R组大鼠后肢总血流量均增加（P < 0.05），表明血流量增加。局部血流量显示，R组大鼠皮肤血流量未改变，总血流量增加是由于骨骼肌血流量增加。这些结果表明，自愿性跑轮运动可引起骨骼肌血管运输能力和氧化能力的适应性增加，与跑步机训练的大鼠相当，并支持在使用大鼠的运动研究中，将自愿性跑轮运动作为一种压力较小的训练方式。
