1,721,076 research outputs found
Relationship between cellular shape and receptor-mediated endocytosis: an ultrastructural and morphometric study in rat Kupffer cells.
No full textReceptor mediated endocytosis of N-acetylglucosamine and mannose exposing molecules by cultured chick embryo hepatocytes.
No full textReceptor mediated endocytosis of N-acetylglucosamine and mannose exposing molecules by cultured chick embryo hepatocytes
No full textLocalization and interaction of bovine pancreatic trypsin inhibitor and tryptase in the granules of bovine mast cells
No full textThe interaction of bovine pancreatic trypsin inhibitor and bovine tryptase, isolated from liver capsule mast cells, was investigated. They form a complex in vitro with a K(i) of 5.6 nM at pH 8.0 and are localized within the mast cell granules, as shown by immunogold staining at the electron microscope level. In addition, double immunogold electron microscopy revealed that the inhibitor and the enzyme are present in the same granules, where they occur in clusters; this may be taken as an indication of their interaction in vivo and suggests a physiological role for bovine pancreatic trypsin inhibitor in the regulation of tryptase proteolytic activity
Chick hepatic lectins: an electron microscopic study on isolated hepatocytes during development.
No full textGrowth inhibition and induction of specific hepatic phenotype epression by retinoic acid in HepG2 cells
No full textRetinoic acid, the active metabolite of vitamin A, plays a role in the growth and differentiation of a variety of normal and malignant cells. In response to 5 microM retinoic acid the human hepatoma-derived cell line HepG2 underwent significant growth inhibition (not associated with cell death), which reached a level of 80% in comparison with controls, after 12 days of continuous treatment. Retinoic acid also induced morphological changes in these cells, in particular the development of canalicular-like structures, indicating progression to a more differentiated phenotype. In addition, a reduced expression of alpha-fetoprotein was found. We suggest that our results may be important for the design of novel therapeutic approaches using RA for the treatment of liver tumors
The effect of retinoic acid on the re-estabishment of differentiated phenotype in primary culture
No full textThe usefulness of cultured hepatocytes is limited by the gradual loss of their typical physiological functions that occurs in vitro, mainly due to the absence of microenviromental conditions found in vivo. In this study we describe the effect of retinoic acid on the re-establishment of morphological characteristics and on the reorganization of the cytoskeletal network in cultured rat hepatocytes. Results obtained demonstrate that retinoic acid can influence hepatocyte differentiation, as regards the recovery of cell polarity, polyhedric shape and reformation of bile canaliculi and junctional complexes. The main target of this action appears to be the cytoarchitecture of cytoskeletal components, particularly cytokeratin filaments, which regain the configuration present in intact liver. The reorganization of the intermediate filaments does not seem to be dependent on the induction of higher levels of cytokeratin proteins, but rather appears to be due to post-translational regulation. The effect of retinoic acid on the cytoskeletal organization could determine the stabilization of intercellular contacts by means of junctions, leading to the appearance of morpho-functional characteristics typical of well-differentiated hepatocytes
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