Exercise Physiology and Biochemistry Laboratory, Department of Physical Education and Sport Sciences at Serres, Aristotle University of Thessaloniki, Agios Ioannis, 62110 Serres, Greece.
Eur J Appl Physiol. 2013 Apr;113(4):827-38. doi: 10.1007/s00421-012-2493-7. Epub 2012 Sep 15.
This study aimed to assess the arterial pressure (AP) determinants during the muscle metaboreflex in boys and men and to investigate the contribution of baroreflex and sympathovagal function to the metaboreflex-induced responses. Fourteen pre-adolescent boys and 13 men performed a protocol involving: baseline, isometric handgrip exercise, circulatory occlusion, and recovery. The same protocol was repeated without occlusion. During baseline, boys had lower beat-to-beat AP, higher heart rate (HR), and lower low/high frequency HR variability. During exercise, a parasympathetic withdrawal was evident in both groups. In adults, HR was the key contributor to the pressure response, with no changes in stroke volume, whereas in boys, the lower HR increase was counterbalanced by an increase in stroke volume, resulting in similar relative increases in AP in both groups. In recovery, boys exhibited a faster rate of HR-decay, rapid vagal reactivation, and greater decrease in TPR than men. An overshoot in baroreceptor sensitivity was observed in men. The isolated metaboreflex resulted in a similar AP elevation in both age groups (by ~15 mmHg), and attenuated spontaneous baroreceptor sensitivity. However, during the metaboreflex, pre-adolescent males exhibited a lower increase in peripheral resistance and a greater bradycardic response than adults, and a fast restoration of vagal activity to non-occlusion levels. During metaboreflex, boys were capable of eliciting a pressure response similar to the one elicited by men; however, the interplay of the mechanisms underlying the rise in AP differed between the two groups with the vagal contribution being greater in the younger participants.
本研究旨在评估男孩和男性肌肉代谢反射时动脉压（AP）的决定因素，并探讨压力反射和交感神经迷走神经功能对代谢反射引起的反应的贡献。14 名青春期前男孩和 13 名男性完成了一项涉及基线、等长握力运动、循环闭塞和恢复的方案。没有闭塞的情况下重复了相同的方案。在基线时，男孩的心率变异性（HRV）更低，AP 更低，HR 更高。在运动期间，两组均出现迷走神经传出抑制。在成人中，HR 是压力反应的关键贡献者，心输出量没有变化，而在男孩中，HR 增加较低被心输出量增加所抵消，导致两组的 AP 相对增加相似。在恢复期间，男孩的 HR 衰减更快，迷走神经快速再激活，总外周阻力（TPR）下降幅度大于男性。在男性中观察到压力感受器敏感性的超射。孤立的代谢反射在两个年龄组中均导致相似的 AP 升高（约 15mmHg），并减弱了自发性压力感受器敏感性。然而，在代谢反射期间，青春期前男性的外周阻力增加较低，心动过缓反应大于成年人，并且迷走神经活动迅速恢复到非闭塞水平。在代谢反射期间，男孩能够引起与男性引起的压力反应相似的反应；然而，两组之间引起 AP 升高的机制相互作用不同，年轻参与者的迷走神经贡献更大。
