抄録
One of the major functions of the lymphatic system is to return plasma proteins from the interstitial space to the blood stream. Previously, we have demonstrated that small molecular FITC-dextran are permeable from the intraluminal to extraluminal space of isolated lymph vessels and that the endothelial cell surface structure plays a barrier role in effective permeability of medium size of FITC-dexran through the wall of the lymph vessels (Am. J. Physiol. 289: H1676-H1682, 2005). In the present study, we further investigated the effects of trypsin, which is useful enzyme for removal of lymphatic endothelial cells in vitro, on effective permeability of large size of FITC-dextran (77 KDa) in isolated lymph vessels. Afferent lymph vessels were isolated from iliac lymph nodes of Wistar rats. The isolated lymph vessels were cannulated with glass-micropipettes and perfused with Krebs-bicarbonate solution with or without 77 KDa FITC-dextran. Changes in the intensity of 77 KDa FITC-dextran in an intraluminal space of the lymph vessels were measured by a video-microscope system and the concentration of 77 KDa FITC-dextran were calculated before and after treatment with trypsin. 77 KDa FITC-dextran did not permeate the wall of lymph vessels before and after the treatment with trypsin. These results suggest that the non-endothelial wall structure of lymph vessels may be a barrier for effective permeability of a large size of FITC-dextran in vitro. [J Physiol Sci. 2006;56 Suppl:S132]
