Zonulae occludentes in the epidermis of the snakeNatrix natrix L.

1980 ◽  
Vol 36 (1) ◽  
pp. 110-112 ◽  
Author(s):  
L. Landmann
Keyword(s):  
Zonulae Occludentes

Zonulae occludentes im Pansenepithel der Ziege

1972 ◽  
Vol 124 (2) ◽  
pp. 39-43 ◽  
Author(s):  
B. Schnorr ◽  
K. -H. Wille
Keyword(s):  
Zonulae Occludentes

Gap junctions and zonulae occludentes of hepatocytes during biliary atresia in the lamprey

1987 ◽  
Vol 19 (4) ◽  
pp. 531-548 ◽  
Author(s):  
J.H. Youson ◽  
L.C. Ellis ◽  
D. Ogilvie ◽  
R.R. Shivers
Keyword(s):  
Gap Junctions ◽  
Biliary Atresia ◽  
Zonulae Occludentes

scholarly journals THE ULTRASTRUCTURAL BASIS OF ALVEOLAR-CAPILLARY MEMBRANE PERMEABILITY TO PEROXIDASE USED AS A TRACER

1968 ◽  
Vol 37 (3) ◽  
pp. 781-793 ◽  
Author(s):  
Eveline E. Schneeberger-Keeley ◽  
Morris J. Karnovsky
Keyword(s):  
Epithelial Cells ◽  
Protein Transport ◽  
Uranyl Acetate ◽  
Basement Membranes ◽  
Small Molecular Weight ◽  
Zonulae Occludentes ◽  
Capillary Membrane ◽  
Pinocytotic Vesicles ◽  
Intercellular Clefts ◽  
Alveolar Capillary

The permeability of the alveolar-capillary membrane to a small molecular weight protein, horseradish peroxidase (HRP), was investigated by means of ultrastructural cytochemistry. Mice were injected intravenously with HRP and sacrificed at varying intervals. Experiments with intranasally instilled HRP were also carried out. The tissue was fixed in formal-dehyde-glutaraldehyde fixative. Frozen sections were cut, incubated in Graham and Karnovsky's medium for demonstrating HRP activity, postfixed in OsO4, and processed for electron microscopy. 90 sec after injection, HRP had passed through endothelial junctions into underlying basement membranes, but was stopped from entering the alveolar space by zonulae occludentes between epithelial cells. HRP was demonstrated in pinocytotic vesicles of both endothelial and epithelial cells, but the role of these vesicles in net protein transport appeared to be minimal. Intranasally instilled HRP was similarly prevented from permeating the underlying basement membrane by epithelial zonulae occludentes. Pulmonary endothelial intercellular clefts stained with uranyl acetate appeared to contain maculae occludentes rather than zonulae occludentes. HRP did not alter the ultrastructure of these junctions.

scholarly journals Lens metabolic cooperation: a study of mouse lens transport and permeability visualized with freeze-substitution autoradiography and electron microscopy.

1980 ◽  
Vol 86 (2) ◽  
pp. 576-589 ◽  
Author(s):  
D A Goodenough ◽  
J S Dick ◽  
J E Lyons
Keyword(s):  
Electron Microscopy ◽  
Epithelial Cells ◽  
Freeze Fracture ◽  
Freeze Substitution ◽  
Species Variation ◽  
Metabolic Cooperation ◽  
Zonulae Occludentes ◽  
Lens Fibers ◽  
Mouse Lens

Transport of metabolites is demonstrated between compartments of the adult mouse lens by freeze-substitution autoradiography. In vivo patterns of lysine incorporation are compared with in vitro patterns of lysine, glucose, uridine, and deoxyglucose incorporation. Intracellular and extracellular distributions of tritiated metabolites are determined by comparison of transported substrates with the nontransported molecules of similar molecular size: mannitol and sucrose. The permeability of the lens intercellular spaces is probed with Procion Yellow at the level of fluorescence microscopy, and with horseradish peroxidase at the electron microscope level. Freeze-fracture electron microscopy reveals gap junctions between epithelial cells, between lens fibers, and between epithelial cells and lens fibers. Zonulae occludentes (tight junctions) are not routinely observed between epithelial cells in the mouse. This latter result is subject to species variation, however, since zonulae occludentes are abundant between chicken epithelial cells. The permeability results suggest that the lens cells are capable of metabolic cooperation, mediated by an extensive gap junction network.

scholarly journals Loss and reappearance of gap junctions in regenerating liver.

1978 ◽  
Vol 78 (2) ◽  
pp. 554-564 ◽  
Author(s):  
A G Yee ◽  
J P Revel
Keyword(s):  
Gap Junctions ◽  
Liver Regeneration ◽  
Partial Hepatectomy ◽  
Rat Liver ◽  
Close Association ◽  
Freeze Fracture ◽  
Regenerating Liver ◽  
Bile Canaliculi ◽  
Zonulae Occludentes ◽  
Fracture Study

Changes in intercellular junctional morphology associated with rat liver regeneration were examined in a freeze-fracture study. After a two-thirds partial hepatectomy, both gap junctions and zonulae occludentes were drastically altered. Between 0 and 20 h after partial hepatectomy, the junctions appeared virtually unchanged. 28 h after partial hepatectomy, however, the large gap junctions usually located close to the bile canaliculi and the small gap junctions enmeshed within the strands of the zonulae occudentes completely disappeared. Although the zonulae occludentes bordering the bile canaliculi apparently remained intact, numerous strands could now be found oriented perpendicular to the canaliculi. In some instances, the membrane outside the canaliculi was extensively filled with isolated junctional strands, often forming very complex configurations. About 40 h after partial hepatectomy, very many small gap junctions reappeared in close association with the zonulae occludentes. Subsequently, gap junctions increased in size and decreased in number until about 48 h after partial hepatectomy when gap junctions were indistinguishable in size and number from those of control animals. The zonulae occludentes were again predominantly located around the canalicular margins. These studies provide further evidence for the growth of gap junctions by the accretion of particles and of small gap junctions to form large maculae.

Intercellular Junctions and Cell Contacts in Inverterbrates

1978 ◽  
Vol 36 (3) ◽  
pp. 673-691
Author(s):  
N.J. Lane
Keyword(s):  
Gap Junctions ◽  
Tight Junctions ◽  
Intercellular Junctions ◽  
Cell Contacts ◽  
Zonulae Occludentes

Invertebrates possess many of the same kind of intercellular junctions as vertebrates although there are frequently structural distinctions between them. Gap junctions, desmosomes and tight junctions are present in invertebrate tissues but their cells may also possess other junctions including the septate, continuous and scalariform types which do not conventionally occur between vertebrate cells. Junctions of the gap, desmosomal and septate variety have been observed in a range of invertebrates including coelenterates such as Hydra (Hand & Gobel, 1972; Filshie & Flower, 1977), molluscs (Flower, 1971; Gilula f. Satir, 1971), "worms' from several phyla (Quick & Johnson, 1977; Flower, 1977) and arthropods including crustaceans (Hudspeth & Revel, 1971; Peracchia, 1973a,b; Lane & Abbott, 1975; Shivers & Chauvin, 1977), chelicerates (Johnson, Herman & Preus, 1973; Lane, 1978a) and insects (Satir & Gilula, 1973; Lane, Skaer & Swales, 1977). However, the intercellular associations known as tight junctions (zonulae occludentes), continuous junctions (zonula continua) and scalariform junctions seem not to occur in invertebrate groups other than the arthropods, at least they have not thus far been reported.

A new occludens-like junction linking endothelial cells of small capillaries (probably venules) of rat jejunum

1975 ◽  
Vol 18 (3) ◽  
pp. 545-551
Author(s):  
L.A. Staehelin
Keyword(s):  
Endothelial Cells ◽  
Tight Junctions ◽  
Plasma Membranes ◽  
Rat Jejunum ◽  
Focal Points ◽  
Zonulae Occludentes ◽  
Low Profile ◽  
New Type ◽  
Endothelial Junction ◽  
Small Venule

Freeze-cleave replicas of small capillaries of rat jejunum have revealed the presence of a new type of junction linking endothelial cells. This new junction reveals tight junctions (zonulae occludentes) in that the adjacent plasma membranes are held closely together along lines of attachment organized in the form of a loose, but frequently discontinuous network. In contrast to tight junctions, the A-face ridges possess a very low profile, and only at low shadowing angles can a repeating, particulate substructure occasionally be resolved. The shallow B-face furrows lack any particulate components. Images of cross-fractured focal points of attachment suggest that the external leaflets of adjacent membranes are closely apposed but not actually fused, as is the case with zonulae occludentes. It appears that this new type of endothelial junction is characteristic of small venules. Thus we propose that it be termed small venule endothelial junction.

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