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Ultrastructure of myocardial widened Z bands and endocardial cells in two teleostean species

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Widened myocardial Z bands and endocardial cells are described in two teleostean species Cichlasoma meeki and Corydoras aeneus. Widened Z bands containing mainly amorphous and electron-dense material were seen in a number of myocardial cells. Further, similar material may occur in large amounts beneath the sarcolemma and at intercellular junctions. Occasionally, we observed continuity between the latter material and that in expanded Z bands.

In C. meeki the ventricular endocardial layer consists of two structurally different cell types, whereas in C. aeneus only one cell type was seen. The functional aspects of widened Z bands are discussed.

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Correspondence to Dr. Ingvar Leiv Leknes.

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Leknes, I.L. Ultrastructure of myocardial widened Z bands and endocardial cells in two teleostean species. Cell Tissue Res. 218, 23–28 (1981).

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Key words

  • Cardiac muscle (teleosts)
  • Z band
  • Endocardial cells