Nom du corpus

Corpus Systématique Animale

Titre du document

Freeze-fracture and morphometric analysis of occluding junctions in rectal glands of elasmobranch fish

Lien vers le document
Éditeur
Springer (journals)
Langue(s) du document
Anglais
Type de document
Research-article
Nom du fichier dans la ressource
Poissons_v2b_003803
Auteur(s)
  • Stephen A. Ernst 1
  • Seth R. Hootman 1
  • James H. Schreiber 1
  • Clara V. Riddle 1
Affiliation(s)
  • 1) Department of Anatomy, University of Michigan, Medical Sciences II, 48109, Ann Arbor, Michigan
Résumé

The structure of occluding junctions in secretory and ductal epithelium of salt-secreting rectal glands from two species of elasmobranch fish, the spiny dogfishSqualus acanthias and the stingrayDasyatis sabina, was examined by thin-section and freeze-fracture electron microscopy. In both species, occluding junctions between secretory cells are shallow in their apical to basal extent and are characterized by closely juxtaposed parallel strands. Average strand number in the dogfish was 3.5±0.2 with a mean depth of 56±5 nm; in the stingray a mean of 2.0±0.2 strands encompassed an average depth of 18±3 nm. In contrast, the linear extent of these junctions was remarkably large due to the intermeshing of the narrow apices of the secretory cells to form the tubular lumen. Morphometric analysis gave values of 66.8±2.5 and 74.9±4.6 m/cm2 for the length of junction per unit of luminal surface area in the dogfish and stingray, respectively. This junctional morphology is similar to that generally described for “leaky” epithelia. In comparison, the stratified ductal epithelium which carries the NaCl-rich secretion to the intestine is characterized by extensive occluding junctions which extend 0.6–0.8 ?m in depth and consist of a mean of 12 strands arranged in an anastomosing network, an architectural pattern typical of “tight” epithelia. The length density of these junctions in the dogfish rectal gland was 7.6±0.1 m/cm2. The junctional architecture of the rectal gland secretory epithelium (few strands, large junctional length densities) is similar to that described for several other hypertonic secretory epithelia [20, 34] and is compatible with the recent model for salt secretion in rectal glands [39] and in other Cl? secretory epithelia which posits a conductive paracellular pathway for transepithelial Na+ secretion from intercellular space to the lumen to form the NaCl-rich secretory product.

Catégories Science-Metrix
  • 1 - health sciences
  • 2 - biomedical research
  • 3 - physiology
Catégories INIST
  • 1 - sciences appliquees, technologies et medecines
  • 2 - sciences biologiques et medicales
  • 3 - sciences biologiques fondamentales et appliquees. psychologie
Catégories Scopus
  • 1 - Life Sciences ; 2 - Biochemistry, Genetics and Molecular Biology ; 3 - Cell Biology
  • 1 - Life Sciences ; 2 - Biochemistry, Genetics and Molecular Biology ; 3 - Physiology
  • 1 - Life Sciences ; 2 - Biochemistry, Genetics and Molecular Biology ; 3 - Biophysics
Catégories WoS
  • 1 - science ; 2 - physiology
  • 1 - science ; 2 - cell biology
  • 1 - science ; 2 - biochemistry & molecular biology
Identifiant ISTEX
D7A917E38C28A9D5E5946E2C5221ECF0A2A80D04
Revue

The Journal of Membrane Biology

Année de publication
1981
Présence de XML structuré
Non
Version PDF
1.3
Score qualité du texte
10
Sous-corpus
  • Poissons
Type de publication
Journal
ark:/67375/1BB-156S6SD0-H
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