Dixon J Brandon, Greiner Steven T, Gashev Anatoliy A, Cote Gerard L, Moore James E, Zawieja David C
Department of Biomedical Engineering, Texas A&M University, College Station, 77843-1114, USA.
Microcirculation. 2006 Oct-Nov;13(7):597-610. doi: 10.1080/10739680600893909.
To measure lymphocyte velocity, lymphatic contraction, and shear stress in phasically contracting lymphatics in situ.
A high-speed video system was used to capture multiple contraction cycles in rat mesenteric lymphatic preparations. The images were analyzed to determine fluid velocity, volume flow rate, wall shear stress, and retrograde flow.
Lymphocyte density and flux varied from 326 to 35,500 cells/microL and 206 to 2,030 cells/min, respectively. Lymphatics contracted phasically, with a mean diameter 91 +/- 9.0 microm and amplitudes of 39%. Lymph velocity varied with the phasic contractions in both direction and magnitude with an average of 0.87 +/- 0.18 and peaks of 2.2-9.0 mm/s. The velocity was approximately 180 degrees out of phase with the contraction cycle. The average lymph flow was 13.95 +/- 5.27 microL/h with transient periods of flow reversal. This resulted in an average shear of 0.64 +/- 0.14 with peaks of 4-12 dynes/cm(2).
High-speed lymphocyte tracking provided the spatial and temporal resolution to measure lymphocyte flux throughout the phasic contraction. Poiseuille flow was a reasonable model for estimating wall shear stress through most of the phasic contraction cycle of the intervalvular lymphatic segments. Shear rate was low but had large variations in magnitude compared to that seen in blood vessels.
测量原位阶段性收缩淋巴管中的淋巴细胞速度、淋巴管收缩及剪切应力。
使用高速视频系统捕捉大鼠肠系膜淋巴管标本中的多个收缩周期。对图像进行分析以确定流体速度、体积流量、壁面剪切应力和逆流情况。
淋巴细胞密度和通量分别在326至35500个细胞/微升和206至2030个细胞/分钟之间变化。淋巴管呈阶段性收缩，平均直径为91±9.0微米，振幅为39%。淋巴速度随阶段性收缩在方向和大小上变化，平均为0.87±0.18毫米/秒，峰值为2.2 - 9.0毫米/秒。速度与收缩周期大约相差180度。平均淋巴流量为13.95±5.27微升/小时，有短暂的逆流期。这导致平均剪切力为0.64±0.14，峰值为4 - 12达因/平方厘米。
高速淋巴细胞追踪提供了空间和时间分辨率，以测量整个阶段性收缩过程中的淋巴细胞通量。泊肃叶流是估计瓣膜间淋巴段大部分阶段性收缩周期壁面剪切应力的合理模型。剪切速率较低，但与血管相比大小变化较大。
