Figure 5.

Structure of the EC contacts and junctions in rats and mice. (A) ECs of blood capillary in derma. Platinum replicas obtained after tangential freeze-fracture of the EC near the inter-endothelial contact. Green arrow indicates the fracture of tight junction. Red arrow demonstrates the fracture of caveolae. (B) The freeze-fracture of the typical TJ between ECs of blood brain capillary. Green arrows indicate the locking fibril of TJ. (C,D) Serial virtual tomography electron microscopic slices. White arrows show the locking fibrils of TJ which appears as a white dot connecting two membranes of opposite ECs. (E) Scheme of TJ. On the freeze-fracture, of the contact zone of ECs, locking fibrils consisting of intramembrane particles appear as widely anastomosing and fence-like elevations (ridges; black arrow)) or depressions (grooves; magenta arrow). (F) The tile-like contact between ECs. It is supplemented with TJ (white arrow). The green arrow indicates the near-contact cytoplasmic protrusions between ECs of blood capillary in brain. Red arrow shows clathrin-coated pit on APM of EC. On the surface of APM the glycocalyx is visible. (G) Interdigitating contact between ECs of lymphatic thoracic duct. (H) Gap junctions (arrow) between ECs of rat thoracis lymphatic duct on the routine transmission EM section. (I) Freeze fracture of gap junction (white arrow) between two ECs of rat aorta. Gap junctions appear as an aggregate of intramembrane particles. (J) Open contacts (arrows) between ECs of rat aorta within the zone of the turbulent blood flow. Images (A,B,E) are taken from Figure 25 presented by Komissarchik and Mironov [19]. Images (C,D) are taken from Figure 5F by Kakogiannos et al. [80]. The image in agreement with the CC By license. The mage (J) is taken from Figure 3G by Mironov et al. [6] in agreement with the CC By license. Scale bars: 165 nm (A); 70 nm (B); 65 nm (C,D); 80 nm (F); 110 nm; 80 nm (H); 100 nm (I); 5.1 µm (J).