Summary
The distribution of horseradish peroxidase and lanthanum chloride within the full term chorioallantoic placenta of the rat was examined after administration of these tracers into the umbilical artery. Both tracers rapidly traverse the capillary endothelium. Transendothelial channels, fenestrations and micropinocytotic vesicles provide the main pathways. Intercellular clefts which are either patent or interrupted by leaky intercellular junctions, also contribute to a rapid passage of low and high molecular weight substances. Deep channel-like invaginations, effecting an increase of the exchange area of layer III, are freely accessible to the tracers from the interspace between the capillary endothelium and trophoblastic layer III. The invaginations, however, are not in continuity with the interspace between layers II and III, verifying the syncytial character of layer III. Neither an uptake of the tracers nor a passage across layer III is observed. The main permeability barrier to feto-maternal transfer within the chorioallantoic placenta is localized in the syncytiotrophoblastic layer III. This layer controls the passage of low molecular weight substances and restricts the penetration of high molecular weight substances.
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Becker, V., Seifert, K.: Die Ultrastruktur der Kapillarwand in der menschlichen Placenta zur Zeit der Schwangerschaftsmitte. Z. Zellforsch. 65, 380–396 (1965)
Claude, P., Goodenough, D.: Fracture faces of zonulae occludentes from “tight” and “leaky” epithelia. J. Cell Biol. 58, 390–400 (1973)
Fels, R., Themann, H.: Die Permeabilität der Mäuseplacenta für Meerrettichperoxidase. Eine elektronenmikroskopische Untersuchung. Cytobiologie 3, 162–171 (1971)
Forssmann, W.G., Metz, J., Heinrich, D.: Gap junctions in the hemotrichorial placenta of the rat. J. Ultrastruct. Res. 53, 374–381 (1975)
Heinrich, D., Metz, J., Raviola, E., Forssmann, W.G.: Ultrastructure of perfusion-fixed fetal capillaries in the human placenta. Cell Tiss. Res. 172, 152–169 (1976)
Herms, V., Heinrich, D., Kubli, F., Metz, J.: Über die Verteilung von Aminosäuren in der trächtigen Ratte: intravenöse, intraamniale und intrafetale Applikation von 14C-L-Tyrosin. Z. Geburtsh. Perinat. 178, 337–341 (1974)
Humbert, F., Grandchamp, A., Pricam, C., Perrelet, A., Orci, L.: Morphological changes in tight junctions of Necturus maculosus proximal tubules undergoing saline diuresis. J. Cell Biol. 69, 90–96 (1976)
Jollie, W.P.: Fine structural changes in placental labyrinth of the rat with increasing gestational age. J. Ultrastruct. Res. 10, 27–47 (1964)
Metz, J., Aoki, A., Forssmann, W.G.: Studies on ultrastructure and permeability of the hemotrichorial placenta. I. Intercellular junctions of layer I and tracer administration into the maternal compartment. Cell Tiss. Res. 192, 391–407 (1978)
Metz, J., Aoki, A., Merlo, M., Forssmann, W.G.: Morphological alterations and functional changes of interhepatocellular junctions induced by bile duct ligation. Cell Tiss. Res. 182, 299–310 (1977)
Metz, J., Heinrich, D., Forssmann, W.G.: Ultrastructure of the labyrinth in the rat full term placenta. Anat. Embryol. 149, 123–148 (1976a)
Metz, J., Heinrich, D., Forssmann, W.G.: Gap junctions in hemodichorial and hemotrichorial placentae. Cell Tiss. Res. 171, 305–315 (1976b)
Pappenheimer, J.R.: Passage of molecules through capillary walls. Physiol. Rev. 33, 387–423 (1953)
Robertson, T.A., Archer, J.M., Papadimitriou, J.M., Walters, M.N.J.: Transport of horseradish peroxidase in the murine placenta. J. Path. 103, 141–147 (1971)
Ryan, R.B., Leventhal, M., Karnovsky, M.J.: A freeze-fracture study of the junctions between glomerular epithelial cells in aminonucleoside nephrosis. Lab. Invest. 32, 397–403 (1975)
Simionescu, N., Simionescu, M., Palade, G.E.: Permeability of intestinal capillaries. Pathway followed by dextrans and glycogens. J. Cell Biol. 53, 365–392 (1972)
Tillack, T.W.: The transport of ferritin across the placenta of the rat. Lab. Invest. 15, 896–909 (1966)
Wade, J.D., Karnovsky, M.J.: Fracture faces of osmotically disrupted zonulae occludentes. J. Cell Biol. 62, 344–350 (1974)
Weihe, E., Heinrich, D., Metz, J., Forssmann, W.G.: Ultrastructure and permeability of fetal capillaries in the human placenta. (In preparation)
Yee, A.G., Revel, J.P.: Endothelial cell junctions. J. Cell Biol. 66, 200–204 (1975)
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Supported by the German Research Foundation
We are indebted to Ms. D. Labeille and Mrs. Ch. Walenta for technical assistance and stud. med. St. Meairs and Mrs. R. Botz for preparing the manuscript
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Aoki, A., Metz, J. & Forssmann, W.G. Studies on the ultrastructure and permeability of the hemotrichorial placenta. Cell Tissue Res. 192, 409–422 (1978). https://doi.org/10.1007/BF00212322
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DOI: https://doi.org/10.1007/BF00212322