Summary
The ultrastructure of the plasma membrane and the core of microvilli of proximal tubule cells has been investigated by electron microscopy using sectioned and negatively stained material. By the technique of negative staining, a particulated coat is disclosed on the outside of the plasma membrane of microvilli of brush borders isolated from rat, rabbit and ox. This coat is composed of 30 to 60 Å particles and is 150 to 300 Å thick and appears to be a distinguishing feature for the luminal plasma membrane (brush border) of proximal tubule cells. The plasma membrane of the basal part of tubule cells is found to be smooth. By thin sectioning, an axial bundle of 50 to 70 Å diameter filaments regularly arranged in an “1+6 configuration”, one axially located filament being surrounded by a ring of six, is disclosed. The distance from the ring of filaments to the inner surface of the plasma membrane is 250–300 Å, the diameter of the ring 300 Å and the center-to-center distance between filaments 120 Å. Negative staining also discloses 60 Å filaments in microvilli of isolated brush borders. Broken off, single microvilli (fingerstalls) are observed with thin filaments projecting from their broken ends. Filaments up to 1 μ in length are seen. At high magnification, the filaments appear beaded and show strong resemblance with actin filaments isolated from skeletal muscle. Based on present evidence, it is postulated that microvilli constituting renal brush borders possess contractile properties, which may play a role in the absorption process operating at the luminal part of the cells.
Similar content being viewed by others
References
Behnke, O., Rostgaard, J.: A device for mounting glass knives in the ordinary rotary microtome for sectioning plastic-embedded material. Stain Technol. 38, 299–300 (1963).
Behnke, O., Zelander, T.: Preservation of intercellular substances by the cationic dye alcian blue in preparative procedures for electron microscopy. J. Ultrastruct. Res. 31, 424–438 (1970).
Berger, S. J., Sacktor, B.: Isolation and biochemical characterization of brush borders from rabbit kidney. J. Cell Biol. 47, 637–645 (1970).
Björkman, N.: Low magnification electron microscopy in histological work. Acta morph. neerl.-scand. 4, 344–348 (1962).
Bloom, W., Fawcett, D. W.: A textbook of histology, 9. ed. Philadelphia: W. B. Saunders Co. 1968.
Brenner, S., Horne, R. W.: A negative staining method for high resolution electron microscopy of viruses. Biochim. biophys. Acta (Amst.) 34, 103–110 (1959).
Bruchhausen, F. v., Merker, H. J.: Gewinnung und morphologische Charakterisierung einer Basalmembranfraktion aus der Nierenrinde der Ratte. Naunyn-Schmiedebergs Arch. exp. Path. Pharmak. 251, 1–12 (1965).
Bulger, R. E.: The shape of rat kidney tubular cells. Amer. J. Anat. 116, 237–256 (1965).
Durand, A., Durand, M., Berjal, G., Hatt, P.-Y.: Etude du tubule rénal du rat au microscope électronique. Path. et Biol. 15–16/17–18, 781–795 (1967).
Ericsson, J. L. E., Trump, B. F.: Electron microscopy of the uriniferous tubules. In: The kidney, morphology, biochemistry, physiology, ed. by C. Rouiller and A. F. Muller, p. 351. New York: Academic Press 1969.
Estable-Puig, J. F., Bauer, W. C., Blumberg, J. M.: Technical Note: Paraphenylenediamine staining of osmium-fixed, plastic-embedded tissue for light and phase microscopy. J. Neurophat. exp. Neurol. 24, 531–535 (1965).
Fernandez-Moran, H.: Subunit organization of mitochondrial membranes. Science 140, 381 (1963).
Frederiksen, O., Leyssac, P. P.: Transcellular transport of isosmotic volumes by the rabbit gall-bladder. J. Physiol. (Lond.) 201, 201–224 (1969).
Groniowski, J., Biczyskowa, W., Walski, M.: Electron microscope studies on the surface coat of the nephron. J. Cell Biol. 40, 585–601 (1969).
Ham, A. W.: Histology, 6th ed. Philadelphia: J. R. Lippincott Co. 1969.
Hanssen, O. E., Herman, L.: The presence of an axial structure in the microvillus of the mouse convoluted proximal tubular cell. Lab. Invest. 11, 610–616 (1962).
Huxley, H. E.: The double array of filaments in cross-striated muscle. J. biophys. biochem. Cytol. 3, 631–647 (1957).
Johnson, C. F.: Intestinal invertase activity and a macromolecular repeating unit of hamster brush border plasma membrane. In: Sixth Internat. Congr. for Electron Microscopy, Kyoto, Japan, ed. by R. Uyeda, p. 389. Tokyo: Maruzen Co. 1966.
Johnson, C. F.: Disaccharidase: Localization in hamster intestine brush borders. Science 155, 1670–1672 (1967).
Johnson, C. F.: Hamster intestinal brush-border surface particles and their function. Fed. Proc. 28, 26–29 (1969).
Kristensen, B. I., Nielsen, L. E., Rostgaard, J.: A two-filament system and interaction of heavy meromyosin (HMM) with thin filaments in smooth muscle. Z. Zellforsch. 122, 350–356 (1971).
Leyssac, P. P.: Some characteristics of the proximal tubular wall related to reabsorption during luminal occlusion following interruption of glomerular filtration. Acta physiol. scand. 63, 36–45 (1965).
Leyssac, P. P.: The regulation of proximal tubular reabsorption in mammalian kidney. Thesis. Acta physiol. scand. 70, Suppl. 291 (1966).
Lowy, J., Small, J. V.: The organization of myosin and actin in vertebrate smooth muscle. Nature (Lond.) 227, 46–51 (1970).
Markham, R., Frey, S., Hills, G. J.: Methods for the enhancement of image detail and accentuation of structure in electron microscopy. Virology 20, 88–102 (1963).
Maunsbach, A. B.: The influence of different fixatives and fixation methods on the ultrastructure of rat kidney proximal tubule cells. I. Comparison of different perfusion fixation methods and of glutaraldehyde, formaldehyde and osmium tetroxide fixatives. J. Ultrastruct. Res. 15, 242–282 (1966a).
Maunsbach, A. B.: Observations on the segmentation of the proximal tubule in the rat kidney. Comparison of results from phase contrast, fluorescence and electron microscopy. J. Ultrastruct. Res. 16, 239–258 (1966b).
O'Brien, E. J., Bennett, P. M., Hanson, J.: Optical diffraction studies of myofibrillar structure. Phil. Trans. B 261, 201–208 (1971).
Oda, T., Seki, S.: Molecular structure and biochemical function of the microvilli membrane of intestinal epithelial cells with special emphasis on the elementary particles. J. Electron Micr. (Japan) 14, 210–217 (1965).
Parsons, D. F.: Negative staining of thinly spread cells and associated virus. J. Cell Biol. 16, 620–626 (1963).
Rambourg, A., Leblond, C. P.: Electron microscope observations on the carbohydrate-rich cell coat present at the surface of cells in the rat. J. Cell Biol. 32, 27–53 (1967).
Reynolds, E. S.: The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J. Cell Biol. 17, 208–212 (1963).
Rhodin, J.: Correlation of ultrastructural organization and function in normal and experimentally changed proximal convoluted tubule cells of the mouse kidney. Thesis, Karolinska Institutet, Stockholm (1954).
Rhodin, J.: Electron microscopy of the kidney. Amer. J. Med. 24, 661–675 (1958).
Rostgaard, J., Behnke, O.: Perfusion fixation and its application in electron microscopic morphological and histochemical studies. J. Ultrastruct. Res. 14, 416 (1966).
Rostgaard, J., Kristensen, B. I., Nielsen, L. E.: Characterization of 60 Å filaments in endothelial, epithelial, and smooth muscle cells of rat by reaction with heavy meromyosin. J. Ultrastruct. Res. 38, 207 (1972).
Rostgaard, J., Møller, O. J.: Electron microscopy of a microsomal fraction rich in (Na+-K+)-ATPase from kidney cortex. Identification of main components as microvilli by comparison with isolated brush border. Morphological changes accompanying freezing and DOC-activation. In: Sixth Meeting Federation of European Biochemical Societies, Madrid p. 356, abstract No. 1162. Published by the Spanish Biochemical Society (1969).
Rostgaard, J., Møller, O. J.: Electron microscopy of a microsomal fraction rich in (Na+-K+), ATPase and isolated from kidney cortex. Structural changes accompanying freeze- and DOC-activation and identification of main components. Exp. Cell Res. 68, 356–371 (1971).
Rostgaard, J., Thuneberg, L.: Surface structure and internal filaments of microvilli isolated from kidney cortex and small intestine of rat. J. Ultrastruct. Res. 25, 169 (1968).
Sampaio, M. M., Brunner, A., Jr., Filho, B. O.: Aspects of the ultrastructure of the brush border of the kidney of normal mouse. J. biophys. biochem. Cytol. 4, 335–336 (1958).
Sandborn, E. B., Szeberenyi, A., Messier, P.-E.: Filaments, microtubules and membranes. In: Sixth International Congress for Electron Microscopy, Kyoto, Japan, ed. by R. Uyeda, p. 409–410. Tokyo: Maruzen Co., 1966.
Sandborn, E. B.: Cells and Tissues by light and electron microscopy, vol. 2, p. 150. New York: Academic Press 1970.
Steinhausen, M., Iravani, I., Schubert, G. E., Taugner, R.: Auflichtmikroskopie and Histologie der Tubulusdimensionen bei verschiedenen Diuresezuständen. Virchows Arch. path. Anat. 336, 503–527 (1963).
Takesue, Y., Sato, R.: Biochemical and morphological characterization of microvilli isolated from intestinal mucosal cells. J. Biochem. (Tokyo) 64, 885–893 (1968).
Thuneberg, L., Møller, O. J., Rostgaard, J.: Unpublished observations.
Thuneberg, L., Rostgaard, J.: Isolation of brush border fragments from homogenates of rat and rabbit kidney cortex. Exp. Cell Res. 51, 123–140 (1968).
Thuneberg, L., Rostgaard, J.: Motility of microvilli (a film recording). In: Sixth Meeting Federation of European Biochemical Societies, Madrid, p. 270. abstract No 864. Published by the Spanish Biochemical Society (1969).
Thuneberg, L., Rostgaard, J.: Motility of microvilli. A film demonstration. J. Ultrastruct. Res. 29, 578 (1969).
Trump, B. F., Ericsson, J. L. E.: The effect of the fixative solution on the ultrastructure of cells and tissues. A comparative analysis with particular attention to the proximal convoluted tubules of rat kidney. Lab. Invest. 14, 1245–1323 (1965).
Warren, L., Glick, M. C., Nass, M. K.: The isolation of animal cell membranes. In: The specificity of cell surfaces, ed. by B. D. Davis and L. Warren, p. 109. New Jersey: Prentice-Hall, Inc., Englewood Cliffs 1967.
Zwillenberg, L. O.: Filament-carrying tubules demonstrated by negative staining in various mammalian cell types. Z. Zellforsch. 66, 415–426 (1965).
Author information
Authors and Affiliations
Additional information
The authors are indebted to Miss Kirsten Sjöberg for skilled technical assistance, and to the Danish State Research Foundation and the Tuborg Foundation for financial support.
Rights and permissions
About this article
Cite this article
Rostgaard, J., Thuneberg, L. Electron microscopical observations on the brush border of proximal tubule cells of mammalian kidney. Z.Zellforsch 132, 473–496 (1972). https://doi.org/10.1007/BF00306637
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00306637