Hirai T, Visneski M D, Kearns K J, Zelis R, Musch T I
Department of Kinesiology, Kansas State University, Manhattan 66506.
J Appl Physiol (1985). 1994 Sep;77(3):1288-93. doi: 10.1152/jappl.1994.77.3.1288.
The functional role of nitric oxide (NO) release in regulating blood flow (BF) to exercising skeletal muscle was studied in conscious male Sprague-Dawley rats (603 +/- 28 g; n = 6). In this study, BF was measured using radiolabeled microspheres during treadmill exercise (10% grade, 20 m/min) before and after NO synthase (NOS) inhibition with NG-nitro-L-arginine methyl ester (30 mg/kg ia). After NOS inhibition, mean arterial blood pressure increased from resting baseline values and the duration of vasodilator responses to acetylcholine (ACh) injections (3.0 and 10.0 micrograms/kg ia) was diminished (P < 0.05), demonstrating reduced NOS function. During exercise, BF to the kidneys and organs of the gut was reduced after NOS inhibition. In addition, BF was reduced in 16 of the 28 individual hindquarter muscles or muscle parts. Moreover these reductions in BF were linearly correlated with the estimated sum of the percentage of fast-twitch oxidative glycolytic (FOG) and slow-twitch oxidative (SO) types of fibers found in each muscle [delta BF = -1.1 (%SO + %FOG) + 16.4; r = 0.88, P < 0.001]. These results suggest that NO-mediated vasodilation contributes to the BF responses within and among the muscles of the rat's hindquarters during exercise.
在清醒的雄性Sprague-Dawley大鼠（603±28克；n = 6）中研究了一氧化氮（NO）释放对调节运动骨骼肌血流量（BF）的功能作用。在本研究中，在使用NG-硝基-L-精氨酸甲酯（30毫克/千克腹腔注射）抑制一氧化氮合酶（NOS）之前和之后，通过放射性微球在跑步机运动（坡度10%，速度20米/分钟）期间测量BF。抑制NOS后，平均动脉血压从静息基线值升高，对乙酰胆碱（ACh）注射（3.0和10.0微克/千克腹腔注射）的血管舒张反应持续时间缩短（P<0.05），表明NOS功能降低。运动期间，抑制NOS后肾脏和肠道器官的BF降低。此外，28个单独的后肢肌肉或肌肉部分中有16个的BF降低。而且，这些BF的降低与每个肌肉中快肌氧化糖酵解（FOG）和慢肌氧化（SO）纤维类型百分比的估计总和呈线性相关[δBF = -1.1（%SO + %FOG）+ 16.4；r = 0.88，P<0.001]。这些结果表明，NO介导的血管舒张有助于运动期间大鼠后肢肌肉内部和之间的BF反应。
