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Updated: Aug 20, 2026

Isolation of Human Lymphatic Endothelial Cells by Multi-parameter Fluorescence-activated Cell Sorting
Published on: May 1, 2015
The second valve system in lymphatics
1Department of Bioengineering, The Whitaker Institute for Biomedical Engineering, University of California, San Diego, La Jolla, California 92093-0412, USA. gwss@bioeng.ucsd.edu
Abstract:
The mechanism for interstitial fluid uptake into the lymphatics of the microcirculation remains speculative and uncertain. There exists a system of intralymphatic valves that prevent reflow along the length of the lymphatic channels, but these valves are insufficient to provide unidirectional flow at the level of the initial lymphatics. We propose that initial lymphatics have a two-valve system: a (primary) valve system at the level of the endothelium in addition to the classical (secondary) intralymphatic valves. The primary valves, in conjunction with the secondary valves, provide a mechanism that facilitates the unidirectional flow during periodic compression and expansion of initial lymphatics.
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