Ultrastructural changes during development of gap junctions in rabbit left ventricular myocardial cells

Shibata, Yosaburo; Nakata, Kazuyasu; Page, Ernest W.

doi:10.1016/s0022-5320(80)90078-7

Cited by 49 publications

(26 citation statements)

References 18 publications

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“…Such a junctional configuration has also been considered characteristic of embryonic tissue (4,39). Our results would however indicate that this junction form is in fact normal in functional adult myocardium, as has also been suggested from some recent in vitro studies (22).…”

Section: Discussionsupporting

confidence: 83%

“…Others have shown, however, that the relationship between morphology and functional state may be more complex, and have therefore tried either to define their experimental conditions more rigorously (22) and/or to use ultrarapid freezing techniques (13,22,33,39) in an attempt to get closer to the true functional (or nonfunctional) configuration of the junction. Recently there have even been indications that coupling in some cell types may be associated with the presence of THE JOURNAL of CELL BioLocr " VOLUME 99 AUGUST 1984 [453][454][455][456][457][458][459][460][461][462][463] © The Rockefeller University Press -0021-952-5/84/08/0453/11 $1 .00 ordered arrays of connexons (22,39), a complete reversal of the conclusions in the works noted above.…”

mentioning

confidence: 99%

“…Recently there have even been indications that coupling in some cell types may be associated with the presence of THE JOURNAL of CELL BioLocr " VOLUME 99 AUGUST 1984 [453][454][455][456][457][458][459][460][461][462][463] © The Rockefeller University Press -0021-952-5/84/08/0453/11 $1 .00 ordered arrays of connexons (22,39), a complete reversal of the conclusions in the works noted above.…”

mentioning

confidence: 99%

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Gap junction connexon configuration in rapidly frozen myocardium and isolated intercalated disks.

Green¹,

Severs²

1984

The Journal of Cell Biology

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By using two ultrarapid freezing techniques, we have captured the structure of rat and rabbit cardiac gap junctions in a condition closer to that existing in vivo than to that previously achieved . Our results, which include those from fully functional hearts frozen in situ in the living animal, show that the junctions characteristically consist of multiple small hexagonal arrays of connexons . In tissue frozen 10 min after animal death, however, unordered arrays are common. Examination of junction structure at intervals up to 40 min after death reveals a variety of configurations including dispersed and close-packed unordered arrays, and hexagonal arrays . By use of an isolated intercalated disk preparation, we show that the configuration of cardiac gap junctions in vitro cannot be altered by factors normally considered to induce functional uncoupling .These experiments demonstrate that, contrary to the conclusions of some earlier studies

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Section: Discussionsupporting

confidence: 83%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Gap junction connexon configuration in rapidly frozen myocardium and isolated intercalated disks.

Green¹,

Severs²

1984

The Journal of Cell Biology

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“…This appearance is common in developing hearts and appears to be related to growth spurts of the junctions (Shibata et al, 1980). Junctions from control myoblasts and monensin-treated cells (25 laM for 15 min) were similar (see Fig.…”

Section: Gap Junction Ultrastructurementioning

confidence: 75%

“…Values for center-to-center spacing of 9.4 + 2 nm in sheep Purkinje fibers (Dahl & Isenberg, 1980) and 10.9+0.1 nm in one day old rabbit ventricle (Shibata et al, 1980) are typical. Particle size has been best quantified by Dahl and Isenberg (1980) who found an average of 8.3 _+ 0.5 nm for sheep Purkinje fibers.…”

Section: Discussionmentioning

confidence: 91%

Permeability and structural studies of heart cell gap junctions under normal and altered ionic conditions

1982

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Summary.The permeability and ultrastructure of communicating junctions of cultured neonatal rat ventricular cells are examined under control conditions and during treatments which raise intracellular Ca 2+. Lucifer Yellow (487mol wt) is used to examine junctional permeability. Under normal ionic conditions dye transfer from an injected muscle cell to neighboring muscle cells occurs rapidly (in less than 6 sec) while transfer to neighboring fibroblasts occurs more slowly. Application of monensin, which results in a partial contracture with superimposed asynchrony, or A23187, which results in a partial contracture, do not inhibit the transfer of dye between the muscIe cells. A23187 did result in junctional blockade between muscle cells and fibroblasts. Freezefractured gap junctions from control and monensin-treated cells exhibit no distinguishable differences. Center-to-center spacing was not significantly different, 9.0 nm_+ 1.4 SD versus 9.2 rim+ 1.3 SD, respectively; and particle diameters were virtually unchanged, 8.69 nm+0.9 sD versus 8.61 nm• 1.07 SD, respectively. These results suggest that concentrations of intracellular Ca 2 + sufficient to support a partial contracture and asynchronous contractile activity do not result in a block of intercellular junctions in cultured myocardial cells. These results are discussed in terms of intracelhilar Ca; +-buffering and junctional sensitivity to Ca 2 +.

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Ultrastructure and cell-cell coupling of cardiac myocytes differentiating in embryonic stem cell cultures

Westfall

Pasyk

Yule

et al. 1997

Cell Motil. Cytoskeleton

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Differentiation cultures of embryonic stem (ES) cells can be a useful in vitro system for understanding cardiac myocyte development. However, cell morphometry, sarcomere development, and functional cell‐cell junction formation have not been examined in detail to determine whether ES cell‐derived cardiac myocytes exhibit structural and functional characteristics similar to cardiac myocytes within the developing heart. Therefore, we examined cellular dimensions, sarcomere formation, and cell‐cell contacts in differentiating cardiac myocytes derived from mouse D3‐ES cell cultures. Cells exhibited rod‐shaped morphology and had single centrally located nuclei, typical of maturing cardiac myocytes. The cellular dimensions of 59 individual cardiac myocytes within contracting foci of ES cell cultures were analyzed (length = 42.2 ± 2.1 μm, area = 197 ± 19 μm2, and diameter = 5.5 ± 0.3 μm) and found to be similar to myocytes in vivo. Transmission electron micrographs of ES cell‐derived cardiac myocytes indicated myofibrillar architecture ranged from sparse and disorganized to densely packed, parallel arrays of myofibrils organized into mature sarcomeres. This pattern of myofibrillar assembly in maturing sarcomeres was similar to that observed during in vivo myocyte differentiation. Another hallmark of cardiac development is the formation of intercalated discs, which functionally couple adjacent cardiac myocytes. Electron micrographs indicated nascent intercalated discs were forming in foci of ES cell‐derived cardiac myocytes. In addition, indirect immunostaining with anti‐connexin 43 antibody (Ab), a monoclonal Ab to the gap junction component of the intercalated disc, indicated that gap junctions were present in contracting ES cell foci. Furthermore, microinjection of single cardiac myocytes with Lucifer yellow (2.5 μM) resulted in the spread of fluorescence to adjacent cells within a contracting focus, an indication of functional cell‐cell coupling across these gap junctions. Together, these results indicate ES cell‐derived cardiac myocytes exhibit cell morphology, sarcomere formation, and cell‐cell junctions similar to those observed in cardiac myocytes developing in vivo. Cell Motil. Cytoskeleton 36:43–54, 1997. © 1997 Wiley‐Liss, Inc.

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Ultrastructural changes during development of gap junctions in rabbit left ventricular myocardial cells

Cited by 49 publications

References 18 publications

Gap junction connexon configuration in rapidly frozen myocardium and isolated intercalated disks.

Gap junction connexon configuration in rapidly frozen myocardium and isolated intercalated disks.

Permeability and structural studies of heart cell gap junctions under normal and altered ionic conditions

Ultrastructure and cell-cell coupling of cardiac myocytes differentiating in embryonic stem cell cultures

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