Table 1 Classification of non-sinusoidal non-fenestrated blood capillary microvasculature
NON-SINUSOIDAL CAPILLARY TYPE | Primary anatomic sites of transvascular flow | Determinants of physiologic pore size | Physiologic upper limit of pore size | Representative tissue microvascular beds |
|---|---|---|---|---|
NON-FENESTRATED | •Non-fenestrated endothelial cells •Continuous anionic basement membrane rich in sulphated proteoglycans[64, 86] •Anionic glycocalyx matrix layer on endothelial cell surfaces & interendothelial cell clefts rich in sialyated glycoproteins[69, 142, 152–154] | |||
Non-fenestrated blood capillary with tight junctions | Zona occludens interendothelial junctions •Tight opposition of adjacent endothelial cell membranes at junctions [70, 92, 93, 155] | •Zona Occludens interendothelial cell junctions in series constitute an absolute barrier to the transvascular flow of macromolecules | < 1 nm | •Brain-Spinal Cord [85, 93, 95, 96, 158, 159] •Nerve Endoneurium [160] •Enteric Nervous System [91] |
Non-fenestrated blood capillary with loose junctions | Macula occludens interendothelial junctions •Loose opposition of adjacent endothelial cell membranes at junctions [79, 80] | •Macula Occludens interendothelial cell junctions in series constitute a relative barrier to the transvascular flow of macromolecules | ~5 nm | •Cortical Bone [88] •Adipose tissue [87] •Lung [81] •Intestinal Mesentary [15, 71] •Develop. Ovarian Follicle [94] |