Department of Human Physiology, University of Oregon, Eugene, OR.
School of Physical Education and Sport, University of São Paulo, São Paulo, BRAZIL.
Med Sci Sports Exerc. 2019 Jul;51(7):1487-1497. doi: 10.1249/MSS.0000000000001911.
Histamine is released within skeletal muscle during exercise. In humans, antihistamines have no effect on speed, power output, or time-to-completion of short-duration high-intensity exercise. In mice, blocking histamine's actions decreases speed and duration of endurance tasks. It is unknown if these opposing outcomes are the result of differences in histamine's actions between species or are related to duration and/or intensity of exercise, as blocking histamine during endurance exercise has not been examined in humans.
Determine the effects of histamine-receptor antagonism on cycling time trial performance in humans, with and without a preceding bout of sustained steady-state exercise.
Eleven (3F) competitive cyclists performed six 10-km time trials on separate days. The first two time trials served as familiarization. The next four time trials were performed in randomized-block order, where two were preceded by 120 min of seated rest (rest) and two by 120 min of cycling exercise (Exercise) at 50% V˙O2peak. Within each block, subjects consumed either combined histamine H1 and H2 receptor antagonists (Blockade) or Placebo, before the start of the 120-min Rest/Exercise.
Blockade had no discernible effects on hemodynamic or metabolic variables during Rest or Exercise. However, Blockade increased time-to-completion of the 10-km time trial compared with Placebo (+10.5 ± 3.7 s, P < 0.05). Slowing from placebo to blockade was not different between rest (+8.7 ± 5.2 s) and Exercise (+12.3 ± 5.8 s, P = 0.716).
Exercise-related histaminergic signaling appears inherent to endurance exercise and may play a role in facilitating optimal function during high-intensity endurance exercise.
确定组胺受体拮抗作用对人类在有或无先前持续稳态运动的情况下进行自行车计时赛表现的影响。
11 名（3 名女性）竞技自行车手在不同的日子里进行了六次 10 公里计时赛。前两次计时赛作为熟悉阶段。接下来的四次计时赛以随机分组的方式进行，其中两次在 50%最大摄氧量峰值的坐姿休息（休息）前进行 120 分钟，两次在自行车运动（运动）前进行 120 分钟。在每个分组中，受试者在开始 120 分钟的休息/运动之前，分别服用联合组胺 H1 和 H2 受体拮抗剂（阻断）或安慰剂。
阻断对休息或运动期间的血液动力学或代谢变量没有明显影响。然而，与安慰剂相比，阻断使 10 公里计时赛的完成时间增加了（+10.5±3.7s，P<0.05）。从安慰剂到阻断的减慢在休息（+8.7±5.2s）和运动（+12.3±5.8s，P=0.716）之间没有差异。
运动相关的组胺能信号似乎是耐力运动所固有的，并且可能在高强度耐力运动中促进最佳功能发挥中发挥作用。
