Abstract
One of the important functions of lymph vessels and lymph nodes is to return plasma proteins from the interstitial space in tissues. There exists few or no report, except for one (Ono, et al: AJP H1676-H1682, 2005), regarding for evaluation of hydrophilic permeability through the walls of lymph vessels. No experiment in vitro model using cultured lymphatic endothelial cells has been reported to elucidate macromolecular permeability through the cell layer. Therefore, we have attempted to develop firstly in vitro assay system to study hydrophilic permeability and then investigated the effects of TNF-α.Rat lymphatic endothelial cells cultured from the thoracic ducts or afferent lymphatic vessels were seeded onto the collagen-coated inserts of double chambers in-vitro vascular permeability assay kit (CHENICON). The cell monolayers were treated with or without TNF-α (10ng/ml) over night, and then fluorescent-labeled dextrans (4, 12, and 77KD) were added on the top of the cells coated on upper chamber to evaluate the hydrophilic permeability. The extent of permeability was determined by measuring fluorescent activity of the solution dropped down the lower chamber. The pretreatment with TNF-α caused a significant increase of the permeability of all FITC-dextran through the cultured endothelial cell layer.These findings suggest that the in vitro assay system may be suitable for hydrophilic permeability through cultured lymphatic endothelial cell layer. Inflammatory cytokine, TNF-α, caused a significant increase of permeability with FITC-dextran. [J Physiol Sci. 2006;56 Suppl:S133]
