McAllister R M
Department of Veterinary Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia 65211, USA.
Med Sci Sports Exerc. 1998 Mar;30(3):375-81. doi: 10.1097/00005768-199803000-00006.
Acute exercise is associated with large increases in cardiac and active skeletal muscle blood flows and reduced blood flows to inactive muscle, skin, kidneys, and organs served by the splanchnic circulation. Splanchnic and renal blood flows are reduced in proportion to relative exercise intensity. Increased sympathetic nervous system outflow to splanchnic and renal vasculature appears to be the primary mediator of reduced blood flows in these circulations, but the vasoconstrictors angiotensin II and vasopressin also make important contributions. Human and animal studies have shown that splanchnic and renal blood flows are reduced less from resting levels during acute exercise after a period of endurance exercise training. Investigations of mechanisms involved in these adaptations suggest that reductions in sympathetic nervous system outflow, and plasma angiotensin II and vasopressin concentrations, are involved in lesser splanchnic and renal vasoconstriction exhibited by trained individuals. In addition, a reduced response to the sympathetic neurotransmitter norepinephrine in renal vasculature may contribute to greater blood flow to the kidney during acute exercise after training. Greater splanchnic and renal blood flows during acute exercise following training are potentially beneficial in that disturbance from homeostasis would be less in the trained state. Additionally, increased splanchnic blood flow in the trained state may confer benefits for glucose metabolism during prolonged exercise.
急性运动与心脏和活跃骨骼肌血流量大幅增加以及非活跃肌肉、皮肤、肾脏和内脏循环供血器官的血流量减少有关。内脏和肾脏血流量会随着相对运动强度成比例减少。交感神经系统向内脏和肾血管系统输出增加似乎是这些循环中血流量减少的主要介导因素，但血管收缩剂血管紧张素II和血管加压素也起到重要作用。人体和动物研究表明，经过一段时间的耐力运动训练后，急性运动期间内脏和肾脏血流量相对于静息水平的减少幅度较小。对这些适应性变化机制的研究表明，交感神经系统输出减少以及血浆血管紧张素II和血管加压素浓度降低，与训练有素的个体表现出的较轻的内脏和肾血管收缩有关。此外，训练后急性运动期间，肾血管系统对交感神经递质去甲肾上腺素的反应减弱，可能有助于增加肾脏血流量。训练后急性运动期间内脏和肾脏血流量增加可能具有潜在益处，因为在训练状态下内环境稳态受到的干扰会更小。此外，训练状态下内脏血流量增加可能对长时间运动期间的葡萄糖代谢有益。
