CHARACTERIZATION OF INTACT MESENTERIC LYMPHATIC PUMP AND ITS RESPONSIVENESS TO ACUTE EDEMAGENIC STRESS
CHARACTERIZATION OF INTACT MESENTERIC LYMPHATIC PUMP AND ITS RESPONSIVENESS TO ACUTE EDEMAGENIC STRESS
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DOI：
10.1152/ajpheart.1989.257.6.h2059
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发表时间：
1989-12-01
影响因子：
--
通讯作者：
GRANGER, HJ
中科院分区：
文献类型：
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作者：
BENOIT, JN;ZAWIEJA, DC;GRANGER, HJ
在对照条件下和使用体内显微镜技术在增强淋巴形成期间分析大鼠肠系膜收集血管的收缩特性。在显微集合淋巴管中同时监测压力和直径，并根据心脏力学的基本原理分析淋巴泵功能。淋巴管收缩周期可分为收缩期2个时相和收缩期4个时相。在对照条件下，舒张期收缩的频率为6.4 +/- 0.61次/min，并排出约67%的舒张末期容积。血浆稀释后10分钟淋巴形成率升高，舒张末期内径、收缩频率、射血分数和每搏输出量增加。在高淋巴流量状态下，淋巴网络中的压力变得不那么脉动。收缩力是淋巴泵变力性变化的指标，当血浆稀释增加淋巴流量时，收缩力不变。此外，淋巴管平滑肌的最大缩短速度在淋巴流量增加期间没有变化。因此，似乎淋巴形成速率的被动增加对淋巴泵几乎没有（如果有的话）正性肌力作用。增加的每搏输出量和收缩频率似乎主要是由于内在的拉伸依赖性机制设置在运动中的升高的前负荷。这些数据代表了第一个完整的收集淋巴管的流量生成和肌肉特性的全面表征，并为今后的研究淋巴收缩的生理调节提供了基础。
The contractile properties of the mesenteric collecting lymphatics of the rat were analyzed under control conditions and during periods of enhanced lymph formation using in vivo microscopic techniques. Pressure and diameter were simultaneously monitored in microscopic collecting lymphatics, and lymphatic pump function was analyzed in accordance with basic principles of cardiac mechanics. The lymphatic contractile cycle was divided into two phases of systole and four phases of diastole. Under control conditions, lymphatics contracted with a frequency of 6.4 +/- 0.61 beats/min and ejected approximately 67% of their end-diastolic volume. Ten minutes after the rate of lymph formation was elevated by plasma dilution, end-diastolic diameter, contraction frequency, ejection fraction, and stroke volume increased. Pressure in the lymphatic network became less pulsatile in high lymph flow states. Contractility, an index of inotropic changes in lymphatic pump, was unaltered when lymph flow was increased by plasma dilution. Furthermore, the maximal shortening velocity of lymphatic smooth muscle did not change during periods of enhanced lymph flow. Thus it appears that passive increases in the rate of lymph formation exert few, if any, inotropic effects on the lymphatic pump. The augmented stroke volume and contraction frequency appear to result mainly from intrinsic stretch-dependent mechanisms set in motion by elevated preload. These data represent the first comprehensive characterization of both the flow-generating and muscle characteristics of intact collecting lymphatics and provide a basis for future studies on the physiological regulation of lymphatic contraction.