He extended the modal describing the low molecular weight electron dense tracer wake in the interendothelial cleft and surrounding tissue (Fu et al., 199S) to describe the time dependent transport of large molecular weight tracers of size 1.0-3,5 mn radius by convection and diffusion in an interendothelial cleft containing a fiber matrix. Thia model provides a quantitative baais to reinterpret electron microscopic studies of the distribution of tracers such as horse radish peroxidase (HRP, MW-40,000, Stokes radius-3.0 nm) along the interendothelial cell cleft from the lumen to the tissue. He show that, in contrast to our results with low molecular weight tracers, the wake of large molecular weight tracers on the abluminal side of the junctional strand ia not likely to be detected because the concentration of the tracer ia predicted to be very low in most experiments. Thus the lack of tracer such as HRP on the abluminal aide of the junctional strand and in the tissue is not aa strong evidence against the presence of a cleft pathway as suggested previously. The model does provide the basis for the design of experiments to locate both the principal molecular sieve and breaks in the junctional strand from the tracer standing gradient on the luminal side of the junctional strand. The approach will also enable testing of models for transcapillary pathways for large molecules by measuring the distribution of fluorescent tracers across microvessel wall and in the tissue surrounding the microvessel using confocal microscopy (Adamson et al., 1995).
|Original language||English (US)|
|State||Published - 1996|
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)
- Biochemistry, Genetics and Molecular Biology(all)
- Cell Biology