Temporal Dynamics of the Rat Thoracic Duct Contractility in the Presence of Imposed Flow
Temporal Dynamics of the Rat Thoracic Duct Contractility in the Presence of Imposed Flow
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DOI：
10.1089/lrb.2017.0049
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发表时间：
2017-12-01
影响因子：
1.4
通讯作者：
Zawieja, David C.
中科院分区：
文献类型：
--
作者：
Gasheva, Olga Yu;Trzeciakowski, Jerome P.;Zawieja, David C.
背景：淋巴管内血流增加的最初阶段表现为淋巴管收缩能力的自我调节的特定的暂时性模式，这种模式在区域淋巴管网络中是不同的。目前的文献主要涉及淋巴管对基础血流量增加的即刻和快速反应。到目前为止，还没有关于淋巴管对相对较长时间的强制流动做出反应的数据。方法和结果：在本研究中，我们测量和分析了分离、插管并在3cmH2O中加压的大鼠胸导管节段在无外加流量条件下和在外加流量(恒定的轴向压力梯度为2cmH2O)4h内的收缩性能。我们发现，在4小时的外加血流中，淋巴紧张性松弛和淋巴收缩频率受到抑制。在短暂的初始下降后，淋巴相收缩幅度在施加流量的第一小时内显著增加，并在施加流量后3小时有恢复到对照水平的趋势。结果，在施加流量的第三个小时结束时，隔离胸导管的泵流量分数(每分钟主动淋巴泵流量)达到并保持了统计学上显著的下降(与对照的无血流状态相比)。结论：我们的新发现为更好地理解淋巴管收缩能力在长时间稳定淋巴流的发展过程中的变化提供了更好的理解。后者可能发生在炎症性组织水肿发展的初始阶段。
Background: The initial periods of increased flow inside lymphatic vessels demonstrate specific temporary patterns of self-tuning of lymphatic vessel contractility that are heterogeneous across regional lymphatic networks. The current literature primarily refers to the immediate and fast reactions of the lymphangions to increases in basal flow. Until now, there were no available data on how the lymphatic vessels react to comparatively longer periods of imposed flow. Methods and Results: In this study, we measured and analyzed the contractility of the rat thoracic duct segments, isolated, cannulated, and pressurized at 3cm H2O at no imposed flow conditions and during 4 hours of imposed flow (constant transaxial pressure gradient of 2cm H2O). We found the development of a progressing lymphatic tonic relaxation and inhibition of the lymphatic contraction frequency over 4 hours of imposed flow. After a short initial decrease, lymphatic phasic contraction amplitude rose significantly during the first hour of imposed flow, and it demonstrated a trend to return toward control levels after 3 hours of imposed flow. As a result, the fractional pump flow (active lymph pumping per minute) of isolated thoracic duct segments reached and maintained a statistically significant decrease (from control no-flow conditions) at the end of the third hour of imposed flow. Conclusions: Our new findings provide a better understanding of how lymphatic contractility changes during the development of prolonged periods of steady lymph flow. The latter may occur during the initial phases of development of an inflammatory-related tissue edema.