title: Freeze-fracture study of the epidermal cells of a teleost with particular reference to intercellular junctions and permeability to tracer.
abstract: The plasmatic membranes, the intercellular junctions and the intercellular spaces of the epidermis of the fish Pimelodus maculatus were studied by freeze-fracture and by lanthanum methods. The observations has confirmed the presence of desmosomes. Gap junctions were not found and the tight junctions can be seen very rarely, arranged to form small discrete maculae. The finger-print pattern due to the microridges of the apical plasma membrane of the superficial cells was studied by direct replicas. The tracer penetrates all the intercellular epidermal spaces but failed to penetrate the dermis, suggesting the presence of a barrier at the dermo-epidermal level.
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000648:ultrastructure; D002463:Cell Membrane Permeability / Q000187:drug effects*; D003599:Cytoskeleton / Q000648:ultrastructure; D003896:Desmosomes / Q000648:ultrastructure; D004817:Epidermis / Q000648:ultrastructure*; D005260:Female; D005399:Fishes / Q000033:anatomy & histology*; D005614:Freeze Fracturing / Q000379:methods; D007365:Intercellular Junctions / Q000648:ultrastructure*; D007811:Lanthanum; D008297:Male; D008854:Microscopy, Electron / Q000379:methods
chemical_list: D007811:Lanthanum