title: Morphological studies of the goldfish hindgut mucosa in organ culture.
abstract: The morphology of the absorptive cells of the goldfish hindgut mucosa, and their capability for horseradish peroxidase (HRP) uptake, were investigated by electron microscopy after a 24-h organ culture. The columnar appearance and the fine structure of the absorptive cells were well preserved for 24 h at room temperature and 37 degrees C with 5% CO2 in air, in all the media used in this study. Mitoses were frequently observed in the epithelium at the bottom of cultured mucosal folds, and re-epitheliazation was also observed in many explants. Some structural changes were, however, noted in the cultured absorptive cells, as compared with the non-cultured absorptive cells; the deep invaginations of the surface membrane between the microvilli decreased in number; supranuclear giant vacuoles were reduced in size or almost disappeared; the distributional pattern of mitochondria in the absorptive cells was altered. The HRP uptake experiments showed that the absorptive cells cultured for 24 h could still take up HRP by endocytosis and transport it, indicating that the absorptive cells maintained their capability of macromolecule uptake and transport after 24 h of culture. In addition, HRP experiments, in which reaction product was detected within numerous cytoplasmic tubules (CT), various vacuoles and CT-vacuole complexes, suggested a close relationship between CT and vacuolar system in the apical cytoplasm during endocytotic events in the absorptive cells.
mesh_terms: D000818:Animals; D004848:Epithelium / Q000648:ultrastructure; D006054:Goldfish; D006735:Horseradish Peroxidase; D007413:Intestinal Mucosa / Q000166:cytology / Q000648:ultrastructure*; D007700:Kinetics; D008854:Microscopy, Electron; D009924:Organ Culture Techniques
chemical_list: D006735:Horseradish Peroxidase