Effect of thermoregulatory function on relationship between cardiopulmonary baroreceptors and body fluid hemeostasis

本研究的主要目的是建立一个连续血容量和血浆电解质的测量系统。在下一步中，我们设计研究在以下条件下，在人类突然扰动血浆容量期间，血容量和电解质变化的机制。结合机械振荡器技术和离子电极法建立的测量系统，使我们能够在人体血流动力学紊乱过程中对血容量和血浆电解质进行精确、连续的测量.在3种不同的水温下研究了血管收缩活动对浸泡过程中血浆体积变化的影响; 32 ℃时血管收缩最大，34.5 ℃时热中性，36 ℃时血管收缩最小。在浸泡的前20-25分钟内血液和血浆密度迅速降低，随后在浸泡的休息期间逐渐降低。这些变化独立于 ...更多信息 e水温，表明经毛细血管液体转移的体积不受血管活性的影响。在饮水后不久观察到一致的血液浓缩，随后进行血液稀释（血容量的双相变化）。这种现象的发生机制是由于血压升高引起的毛细血管壁液体向外移动，吸收后又向内移动.在下体负压（LBNP，-15和-30 mmHg，持续10分钟）后，血液密度立即出现一过性降低，随后血浆容量急剧增加，但未减少，表明血流重新分布。LBNP后8 min发生经毛细血管液体移位，20 min后恢复至原来的位置。本研究证明，本研究的在线系统是一个有用的工具，用于阐明人类短暂和快速的液体穿过毛细血管壁的机制。少

The primary purpose of this study was to establish a system for measuring continuos blood volume and plasma electrolytes. In the next step, we designed to study the mechanisms responsible for the change in blood volume and electrolytes during an abrupt perturbation plasma volume in the following conditions in humans.1. An establishment of the measuring systems in combination of teh mechanical osicillator technique and ion-electrode method enabled us to measure a precise and continuous measurement of blood volume and plasma electrolytes during a course of hemodynamic perturbation in humans.2. Effect of vasomotor activity on plasma volume change during immersion was studied in 3 different water temperatures ; 32ﾟC at maximum vasoconstriction, 34.5ﾟC,thermoneutral, and 36ﾟC at minimmum vasoconstriction. A rapid reduction of blood and plasma densities in the first 20-25 min of imersion followed by a gradual reduction during the rest period of immersion. These changes were independent of th … More e water temperatures, sugesting that the volume of the transcapillary fluid shift is not modified by the vasomotor activity.3. A consistent hemoconcentration has been observed shortly after water drinking followed by a hemodilution (a biphasic change in blood volume). The mechanisms for this phenomenon was attributed to the outward shift of the fluid across the capillary walls because of the initial rise of blood presure and a later inward shift due to the postabsorptive mechanisms.4. A transient lowering of blood density immediately after lower body negative pressure (LBNP,-15 and -30 mmHg, for 10min) followed by a steep increase without reduction in plasma volume, indicating a redistribution of blood flow. The transcapillary fluid shift occurred -8 min after LBNP and returned to the original space in 20 during recovery.In conslusion, the present study proves that the on-line system of the present study is a useful tool for elucidate the mechanisms underlyting the transient and rapid fluid movement across the capilary walls in humans. Less