单次竭尽全力运动后α-肾上腺素能受体反应性改变的证据。
Evidence for altered alpha-adrenoreceptor responsiveness after a single bout of maximal exercise.
作者信息
Convertino Victor A
机构信息
US Army Institute of Surgical Research, Fort Sam Houston, TX 78234-6315, USA.
出版信息
J Appl Physiol (1985). 2003 Jul;95(1):192-8. doi: 10.1152/japplphysiol.00123.2003. Epub 2003 Apr 4.
We studied hemodynamic responses to alpha- and beta-receptor agonists in eight men to test the hypothesis that adrenoreceptor responsiveness is altered within 24 h of the performance of maximal exercise. Adrenoreceptor responsiveness was tested under two experimental conditions (with and without maximal exercise). Adrenoreceptor tests were performed 24 h after each subject performed graded upright cycle ergometry to volitional exhaustion. The 2 test days (experimental conditions) were separated by at least 1 wk, and the order of exercise and no-exercise conditions was counterbalanced. Steady-state graded infusions of phenylephrine (PE) and isoproterenol (Iso) were used to assess alpha- and beta-adrenoreceptor responsiveness, respectively. Slopes calculated from linear regressions between Iso and PE doses and changes in heart rate, blood pressure, and leg vascular resistance for each subject were used as an index of alpha- and beta-adrenoreceptor responsiveness. The slope of the relationship between heart rate and Iso with maximal exercise was 1773 +/- 164 beats x microm-1x kg-1x min-1 compared with 1987 +/- 142 beats x microg-1x kg-1x min-1 without exercise (P = 0.158), whereas the slopes of the relationship between vascular resistance to Iso were -438 +/- 123 peripheral resistance units (PRU) x microg-1x kg-1x min-1 with maximal exercise and -429 +/- 105 x microg-1x kg-1 x min-1 without exercise (P = 0.904). Maximal exercise was associated with greater (P < 0.05) vascular resistance (15.1 +/- 2.8 PRU x microg-1 kg-1x min-1) and mean arterial blood pressure (15.8 +/- 2.1 mmHg. microg-1x kg-1x min-1) responses to PE infusion compared with no exercise (9.0 +/- 2.0 PRU x microg-1 kg-1 x min-1 and 10.9 +/- 2.0 mmHg. microg-1x kg-1x min-1, respectively). These results provide evidence that a single bout of maximal exercise increases alpha1-adrenoreceptor responsiveness within 24 h without affecting beta-cardiac and vascular adrenoreceptor responses.
我们研究了8名男性对α和β受体激动剂的血流动力学反应，以检验最大运动后24小时内肾上腺素能受体反应性会发生改变这一假设。在两种实验条件下（有或无最大运动）测试肾上腺素能受体反应性。在每位受试者进行分级直立自行车运动至自愿疲劳后24小时进行肾上腺素能受体测试。两个测试日（实验条件）间隔至少1周，运动和非运动条件的顺序相互平衡。分别使用去氧肾上腺素（PE）和异丙肾上腺素（Iso）的稳态分级输注来评估α和β肾上腺素能受体反应性。根据每位受试者Iso和PE剂量与心率、血压和腿部血管阻力变化之间的线性回归计算出的斜率，用作α和β肾上腺素能受体反应性的指标。最大运动时心率与Iso之间关系的斜率为1773±164次/微摩尔·千克⁻¹·分钟⁻¹，而无运动时为1987±142次/微克·千克⁻¹·分钟⁻¹（P = 0.158），而最大运动时血管阻力与Iso之间关系的斜率为-438±°123外周阻力单位（PRU）/微克·千克⁻¹·分钟⁻¹，无运动时为-429±105/微克·千克⁻¹·分钟⁻¹（P = 0.904）。与无运动相比（分别为9.0±2.0 PRU/微克·千克⁻¹·分钟⁻¹和10.9±2.0 mmHg/微克·千克⁻¹·分钟⁻¹），最大运动时对PE输注的血管阻力（15.1±2.8 PRU/微克·千克⁻¹·分钟⁻¹）和平均动脉血压（15.8±2.1 mmHg/微克·千克⁻¹·分钟⁻¹）反应更大（P < 0.05）。这些结果提供了证据，表明单次最大运动可在24小时内增加α1肾上腺素能受体反应性而不影响β心脏和血管肾上腺素能受体反应。
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