TY - JOUR
T1 - Mechanism of macromolecule concentration in collecting lymphatics in RAT mesentery
AU - Takahashi, Tatsuhisa
AU - Shibata, Masahiro
AU - Kamiya, Akira
N1 - Funding Information:
This research was supported in part by a Grant-in-Aid for Scienti®c Research (0778076 to T.T.) from the Ministry of Education, Science, and Culture of Japan and a Research Grant (to T.T.) from the Ministry of Health and Welfare of Japan.
PY - 1997/11
Y1 - 1997/11
N2 - The mechanism by which macromolecular contents are concentrated during lymph transport was investigated in the collecting lymphatics of the mesentery of the rat. To examine changes in the concentration of lymph macromolecular tracer (fluorescein isothiocyanate-tagged dextran, MW 148,900) in the rhythmically contractile lymphatics, we quantified the fluorescence intensity of the lymph tracer using an intravital microscopy system with single slit-laser (20 μm in thickness) epi-illumination, regardless of the vasomotion of the lymph vessel. The results for the fluorescence intensity measurement at different sites at distances of about 300-1000 μm along unbranched collecting lymphatics revealed that the concentration of the lymph macromolecular contents was significantly increased during their passage from upstream to downstream (P < 0.05). The fluorescence intensity of lymph tracer in the occluded segment of collecting lymphatics around 1000 μm in length was enhanced during the contraction phase and reduced during the relaxation phase. These results suggest that the filtration of macromolecule-free fluid from the lymph across the lymphatic wall during its contraction plays an important role in the lymph concentration mechanism in the collecting lymphatics, probably due to the Starling forces acting across the lymphatic wall.
AB - The mechanism by which macromolecular contents are concentrated during lymph transport was investigated in the collecting lymphatics of the mesentery of the rat. To examine changes in the concentration of lymph macromolecular tracer (fluorescein isothiocyanate-tagged dextran, MW 148,900) in the rhythmically contractile lymphatics, we quantified the fluorescence intensity of the lymph tracer using an intravital microscopy system with single slit-laser (20 μm in thickness) epi-illumination, regardless of the vasomotion of the lymph vessel. The results for the fluorescence intensity measurement at different sites at distances of about 300-1000 μm along unbranched collecting lymphatics revealed that the concentration of the lymph macromolecular contents was significantly increased during their passage from upstream to downstream (P < 0.05). The fluorescence intensity of lymph tracer in the occluded segment of collecting lymphatics around 1000 μm in length was enhanced during the contraction phase and reduced during the relaxation phase. These results suggest that the filtration of macromolecule-free fluid from the lymph across the lymphatic wall during its contraction plays an important role in the lymph concentration mechanism in the collecting lymphatics, probably due to the Starling forces acting across the lymphatic wall.
KW - Fluorescent intravital microscopy
KW - Lymph to plasma protein ratio
KW - Lymph transport
KW - Lymphatic permeability
KW - Starling forces
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U2 - 10.1006/mvre.1997.2043
DO - 10.1006/mvre.1997.2043
M3 - Article
C2 - 9441890
AN - SCOPUS:0031951590
VL - 54
SP - 193
EP - 205
JO - Microvascular Research
JF - Microvascular Research
SN - 0026-2862
IS - 3
ER -