摘要
A simple and rapid method was established to study vascular permeability by in vitroperfused endothelial cell monolayers cultured on micropore filter membrane.It can be used todetermine filtration coefficient （K<sub>f</sub>） to small molecules and osmotic reflection coefficient （σ） toproteins of the endothelial monolayer.Hanks’ balanced salt solution （HBSS） or 5g/L albuminin HBSS was used to perfuse the confluent endothelial monolayer at the hydrostatic pressure of2.45kPa （25cm H<sub>2</sub>O）.Control K<sub>f</sub> values were 10.1±0.75 and 3.6±0.75μl·min<sup>-1</sup>·cm<sup>-2</sup>·kPa（-1）（±,n=3） respectively for the perfusion of HBSS and albumin HBSS,suggesting that al-bumin may decrease endothelial monolayer permeability to water and small molecules.After ex-posure of endothelial monolayer to 10<sup>-8</sup>mol/L platelet-activating factor （PAF） for 30min,K<sub>f</sub>values increased to 193.1% and 133.3% respectively.Protein clearance rate (μl.min<sup>-1</sup>·cm<sup>-2</sup>)and osmotic reflection coefficient of the control endothelial monolayer were 8.0±3.22 and 0.37±0.09 respectively and those of the PAF treated endothelial monolayer 12.2±2.95μl·min<sup>-1</sup>·cm<sup>-2</sup> and 0.18±0.06,revealing increased permeability to albumin.Computer-assisted imageprocessing demonstrated that PAF treatment decreased cell area while increased cell form factorand intercellular space,suggesting that endothelial cells retracted and rounded,which may bean important mechanism of PAF-induced increase of vascular permeability.
A simple and rapid method was established to study vascular permeability by in vitro perfused endothelial cell monolayers cultured on micropore filter membrane.It can be used to determine filtration coefficient (K_f) to small molecules and osmotic reflection coefficient (σ) to proteins of the endothelial monolayer.Hanks' balanced salt solution (HBSS) or 5g/L albumin in HBSS was used to perfuse the confluent endothelial monolayer at the hydrostatic pressure of 2.45kPa (25cm H_2O).Control K_f values were 10.1±0.75 and 3.6±0.75μl·min^(-1)·cm^(-2)·kPa(-1) ((?)±(?),n=3) respectively for the perfusion of HBSS and albumin HBSS,suggesting that al- bumin may decrease endothelial monolayer permeability to water and small molecules.After ex- posure of endothelial monolayer to 10^(-8)mol/L platelet-activating factor (PAF) for 30min,K_f values increased to 193.1% and 133.3% respectively.Protein clearance rate (μl.min^(-1)·cm^(-2)) and osmotic reflection coefficient of the control endothelial monolayer were 8.0±3.22 and 0.37 ±0.09 respectively and those of the PAF treated endothelial monolayer 12.2±2.95μl·min^(-1)· cm^(-2) and 0.18±0.06,revealing increased permeability to albumin.Computer-assisted image processing demonstrated that PAF treatment decreased cell area while increased cell form factor and intercellular space,suggesting that endothelial cells retracted and rounded,which may be an important mechanism of PAF-induced increase of vascular permeability.
