• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>American Journal of Physiology >Effects of ATP-induced leg vasodilation on VO2 peak and leg O2 extraction during maximal exercise in humans.
【24h】

Effects of ATP-induced leg vasodilation on VO2 peak and leg O2 extraction during maximal exercise in humans.

机译：ATP诱导的腿部血管舒张对人体最大运动过程中VO2峰值和腿部O2提取的影响。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

During maximal whole body exercise VO2 peak is limited by O2 delivery. In turn, it is though that blood flow at near-maximal exercise must be restrained by the sympathetic nervous system to maintain mean arterial pressure. To determine whether enhancing vasodilation across the leg results in higher O2 delivery and leg VO2 during near-maximal and maximal exercise in humans, seven men performed two maximal incremental exercise tests on the cycle ergometer. In random order, one test was performed with and one without (control exercise) infusion of ATP (8 mg in 1 ml of isotonic saline solution) into the right femoral artery at a rate of 80 microg.kg body mass-1.min-1. During near-maximal exercise (92% of VO2 peak), the infusion of ATP increased leg vascular conductance (+43%, P<0.05), leg blood flow (+20%, 1.7 l/min, P<0.05), and leg O2 delivery (+20%, 0.3 l/min, P<0.05). No effects were observed on leg or systemic VO2. Leg O2 fractional extraction was decreased from 85+/-3 (control) to 78+/-4% (ATP) in the infused leg (P<0.05), while it remained unchanged in the left leg (84+/-2 and 83+/-2%; control and ATP; n=3). ATP infusion at maximal exercise increased leg vascular conductance by 17% (P<0.05), while leg blood flow tended to be elevated by 0.8 l/min (P=0.08). However, neither systemic nor leg peak VO2 values where enhanced due to a reduction of O2 extraction from 84+/-4 to 76+/-4%, in the control and ATP conditions, respectively (P<0.05). In summary, the VO2 of the skeletal muscles of the lower extremities is not enhanced by limb vasodilation at near-maximal or maximal exercise in humans. The fact that ATP infusion resulted in a reduction of O2 extraction across the exercising leg suggests a vasodilating effect of ATP on less-active muscle fibers and other noncontracting tissues and that under normal conditions these regions are under high vasoconstrictor influence to ensure the most efficient flow distribution of the available cardiac output to the most active muscle fibers of the exercising limb.
机译：在最大程度的全身运动过程中，VO2的峰值受O2输送的限制。反过来，尽管必须通过交感神经系统限制接近最大运动量的血流，才能维持平均动脉压。为了确定在近乎最大和最大运动量的情况下，增强腿部血管舒张程度是否会导致较高的O2输送和腿部VO2，七名男性在自行车测功计上进行了两次最大增量运动测试。以随机顺序进行一项试验，一项试验不进行（对照运动）以80微克·千克体重-1.min-的速率向右股动脉中输注ATP（1毫升等渗盐溶液中8毫克）。 1。在接近最大运动量（VO2峰值的92％）期间，输注ATP可增加腿部血管电导率（+ 43％，P <0.05），腿部血流量（+ 20％，1.7 l / min，P <0.05），以及腿部O2输送（+ 20％，0.3 l / min，P <0.05）。没有观察到对腿或全身VO2的影响。输注腿中的腿部O2分数提取率从85 +/- 3（对照）降至78 +/- 4％（ATP）（P <0.05），而在左腿中则保持不变（84 +/- 2和83 +/- 2％;对照和ATP; n ＝ 3）。进行最大运动量的ATP输注可使腿部血管电导增加17％（P <0.05），而腿部血流则倾向于增加0.8 l / min（P = 0.08）。但是，在对照和ATP条件下，由于O2的提取量从84 +/- 4降低到76 +/- 4％，全身和腿部VO2峰值均未升高（P <0.05）。总之，在人类进行接近最大运动或最大运动时，下肢骨骼肌血管扩张并不能增强下肢骨骼肌的VO2。 ATP输注导致运动腿的O2提取减少的事实表明ATP对不太活跃的肌纤维和其他非收缩组织的血管舒张作用，并且在正常情况下，这些区域受到高血管收缩剂的影响，以确保最有效的血流有效心输出量到运动肢体最活跃的肌肉纤维的分布。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号