Abstract
We investigated the mechanisms of hamster low-density lipoprotein (LDL) transport across the endothelial barrier in individually perfused venular microvessels in hamster mesentery. These experiments are the first to use microperfusion techniques and quantitative fluorescence microscopy to investigate LDL transport across mammalian microvessel endothelium. The apparent permeability coefficient for hamster LDL, P(sLDL), rose from 2.7 x 10-7 cm/s at control to 23.2 x 10-7 cm/s at the peak of the biphasic increase in microvessel permeability after exposure of the vessels to 100 μM histamine. Close to the peak, P(sLDL) rose 1.85 x 10-7 cm/s for every centimeter of H2O increase in hydrostatic pressure. Thus, at a mean pressure of 11.3 cmH2O, 90% of the LDL flux was coupled to transendothelial water flow by a solvent drag mechanism. The corresponding solvent drag reflection coefficient for hamster LDL was estimated to be ~0.8. These results are consistent with sieving hamster LDL (effective radius 14.9 nm) through equivalent pores of ~22 nm radius. Similar results were found with human LDL (effective radius 13.2 nm) in hamster microvessels. The results provide a bridge between studies of LDL transport across cultured endothelial barriers, where high diffusive permeability coefficients to LDL may obscure the contributions of solvent drag, and studies in whole animals, where the consequences of sieving of LDL at the vessel wall, even in the high permeability state, have not received much attention.
| Original language | English (US) |
|---|---|
| Journal | American Journal of Physiology - Heart and Circulatory Physiology |
| Volume | 268 |
| Issue number | 5 37-5 |
| State | Published - 1995 |
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Keywords
- atherosclerosis
- capillary permeability
- endothelial lipoprotein permeability
- inflammation
- low-density lipoprotein
- macromolecular permeability
- pore theory
- reflection coefficients
ASJC Scopus subject areas
- Physiology
Cite this
Solvent drag of LDL across mammalian endothelial barriers with increased permeability. / Rutledge, John C; Curry, F. E.; Blanche, P.; Krauss, R. M.
In: American Journal of Physiology - Heart and Circulatory Physiology, Vol. 268, No. 5 37-5, 1995.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Solvent drag of LDL across mammalian endothelial barriers with increased permeability
AU - Rutledge, John C
AU - Curry, F. E.
AU - Blanche, P.
AU - Krauss, R. M.
PY - 1995
Y1 - 1995
N2 - We investigated the mechanisms of hamster low-density lipoprotein (LDL) transport across the endothelial barrier in individually perfused venular microvessels in hamster mesentery. These experiments are the first to use microperfusion techniques and quantitative fluorescence microscopy to investigate LDL transport across mammalian microvessel endothelium. The apparent permeability coefficient for hamster LDL, P(sLDL), rose from 2.7 x 10-7 cm/s at control to 23.2 x 10-7 cm/s at the peak of the biphasic increase in microvessel permeability after exposure of the vessels to 100 μM histamine. Close to the peak, P(sLDL) rose 1.85 x 10-7 cm/s for every centimeter of H2O increase in hydrostatic pressure. Thus, at a mean pressure of 11.3 cmH2O, 90% of the LDL flux was coupled to transendothelial water flow by a solvent drag mechanism. The corresponding solvent drag reflection coefficient for hamster LDL was estimated to be ~0.8. These results are consistent with sieving hamster LDL (effective radius 14.9 nm) through equivalent pores of ~22 nm radius. Similar results were found with human LDL (effective radius 13.2 nm) in hamster microvessels. The results provide a bridge between studies of LDL transport across cultured endothelial barriers, where high diffusive permeability coefficients to LDL may obscure the contributions of solvent drag, and studies in whole animals, where the consequences of sieving of LDL at the vessel wall, even in the high permeability state, have not received much attention.
AB - We investigated the mechanisms of hamster low-density lipoprotein (LDL) transport across the endothelial barrier in individually perfused venular microvessels in hamster mesentery. These experiments are the first to use microperfusion techniques and quantitative fluorescence microscopy to investigate LDL transport across mammalian microvessel endothelium. The apparent permeability coefficient for hamster LDL, P(sLDL), rose from 2.7 x 10-7 cm/s at control to 23.2 x 10-7 cm/s at the peak of the biphasic increase in microvessel permeability after exposure of the vessels to 100 μM histamine. Close to the peak, P(sLDL) rose 1.85 x 10-7 cm/s for every centimeter of H2O increase in hydrostatic pressure. Thus, at a mean pressure of 11.3 cmH2O, 90% of the LDL flux was coupled to transendothelial water flow by a solvent drag mechanism. The corresponding solvent drag reflection coefficient for hamster LDL was estimated to be ~0.8. These results are consistent with sieving hamster LDL (effective radius 14.9 nm) through equivalent pores of ~22 nm radius. Similar results were found with human LDL (effective radius 13.2 nm) in hamster microvessels. The results provide a bridge between studies of LDL transport across cultured endothelial barriers, where high diffusive permeability coefficients to LDL may obscure the contributions of solvent drag, and studies in whole animals, where the consequences of sieving of LDL at the vessel wall, even in the high permeability state, have not received much attention.
KW - atherosclerosis
KW - capillary permeability
KW - endothelial lipoprotein permeability
KW - inflammation
KW - low-density lipoprotein
KW - macromolecular permeability
KW - pore theory
KW - reflection coefficients
UR - http://www.scopus.com/inward/record.url?scp=0029016062&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029016062&partnerID=8YFLogxK
M3 - Article
C2 - 7771548
AN - SCOPUS:0029016062
VL - 268
JO - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
JF - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
SN - 1931-857X
IS - 5 37-5
ER -