Elasmobranch rectal gland cell: autoradiographic localization of [3H]ouabain-sensitive Na, K-ATPase in rectal gland of dogfish, Squalus acanthias.
Specific binding of radiolabeled inhibitor was employed to localize the Na-pump sites (Na,K-ATPase) in rectal gland epithelium, a NaCl-secreting osmoregulatory tissue which is particularly rich in pump sites. Slices of gland tissue from spiny dogfish were incubated in suitable [3H]ouabain-containing...
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Rockefeller University Press
1979
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Online Access: | http://dx.doi.org/10.1083/jcb.83.1.16 https://rupress.org/jcb/article-pdf/83/1/16/1636367/16.pdf |
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crrockefelleruni:10.1083/jcb.83.1.16 2024-06-02T08:16:04+00:00 Elasmobranch rectal gland cell: autoradiographic localization of [3H]ouabain-sensitive Na, K-ATPase in rectal gland of dogfish, Squalus acanthias. Eveloff, J Karnaky, K J Silva, P Epstein, F H Kinter, W B 1979 http://dx.doi.org/10.1083/jcb.83.1.16 https://rupress.org/jcb/article-pdf/83/1/16/1636367/16.pdf en eng Rockefeller University Press The Journal of cell biology volume 83, issue 1, page 16-32 ISSN 0021-9525 1540-8140 journal-article 1979 crrockefelleruni https://doi.org/10.1083/jcb.83.1.16 2024-05-07T14:15:26Z Specific binding of radiolabeled inhibitor was employed to localize the Na-pump sites (Na,K-ATPase) in rectal gland epithelium, a NaCl-secreting osmoregulatory tissue which is particularly rich in pump sites. Slices of gland tissue from spiny dogfish were incubated in suitable [3H]ouabain-containing media and then prepared for Na,K-ATPase assay, measurement of radiolabel binding, or quantitative freeze-dry autoradiography at the light microscope level. Gross freezing or drying artifacts were excluded by comparison with additional aldehyde-fixed slices. Characterization experiments demonstrated high-affinity binding which correlated with Na,K-ATPase inhibition and half-saturated at approximately 5 microM [3H]ouabain. At this concentration, the normal half-loading time was approximately 1 h and low-affinity binding to nonspecific sites was negligible. Autoradiographs from both 1- and 4-h incubated slices showed approximately 85% of the bound [3H]ouabain to be localized within a 1-micrometer wide boundary region where the highly infolded basal-lateral cell membrane are closest to the mitochondria. These results establish that most of the enormous Na,K-ATPase activity associated with rectal gland epithelium is in the basal-lateral cell membrane facing interstitial fluid and not in the luminal membrane facing secreted fluid. Moreover, distribution along the basal-lateral membrane appears to be nonuniform with a higher density of enzyme sites close to mitochondria. Article in Journal/Newspaper spiny dogfish Squalus acanthias Rockefeller University Press Journal of Cell Biology 83 1 16 32 |
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Rockefeller University Press |
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crrockefelleruni |
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English |
description |
Specific binding of radiolabeled inhibitor was employed to localize the Na-pump sites (Na,K-ATPase) in rectal gland epithelium, a NaCl-secreting osmoregulatory tissue which is particularly rich in pump sites. Slices of gland tissue from spiny dogfish were incubated in suitable [3H]ouabain-containing media and then prepared for Na,K-ATPase assay, measurement of radiolabel binding, or quantitative freeze-dry autoradiography at the light microscope level. Gross freezing or drying artifacts were excluded by comparison with additional aldehyde-fixed slices. Characterization experiments demonstrated high-affinity binding which correlated with Na,K-ATPase inhibition and half-saturated at approximately 5 microM [3H]ouabain. At this concentration, the normal half-loading time was approximately 1 h and low-affinity binding to nonspecific sites was negligible. Autoradiographs from both 1- and 4-h incubated slices showed approximately 85% of the bound [3H]ouabain to be localized within a 1-micrometer wide boundary region where the highly infolded basal-lateral cell membrane are closest to the mitochondria. These results establish that most of the enormous Na,K-ATPase activity associated with rectal gland epithelium is in the basal-lateral cell membrane facing interstitial fluid and not in the luminal membrane facing secreted fluid. Moreover, distribution along the basal-lateral membrane appears to be nonuniform with a higher density of enzyme sites close to mitochondria. |
format |
Article in Journal/Newspaper |
author |
Eveloff, J Karnaky, K J Silva, P Epstein, F H Kinter, W B |
spellingShingle |
Eveloff, J Karnaky, K J Silva, P Epstein, F H Kinter, W B Elasmobranch rectal gland cell: autoradiographic localization of [3H]ouabain-sensitive Na, K-ATPase in rectal gland of dogfish, Squalus acanthias. |
author_facet |
Eveloff, J Karnaky, K J Silva, P Epstein, F H Kinter, W B |
author_sort |
Eveloff, J |
title |
Elasmobranch rectal gland cell: autoradiographic localization of [3H]ouabain-sensitive Na, K-ATPase in rectal gland of dogfish, Squalus acanthias. |
title_short |
Elasmobranch rectal gland cell: autoradiographic localization of [3H]ouabain-sensitive Na, K-ATPase in rectal gland of dogfish, Squalus acanthias. |
title_full |
Elasmobranch rectal gland cell: autoradiographic localization of [3H]ouabain-sensitive Na, K-ATPase in rectal gland of dogfish, Squalus acanthias. |
title_fullStr |
Elasmobranch rectal gland cell: autoradiographic localization of [3H]ouabain-sensitive Na, K-ATPase in rectal gland of dogfish, Squalus acanthias. |
title_full_unstemmed |
Elasmobranch rectal gland cell: autoradiographic localization of [3H]ouabain-sensitive Na, K-ATPase in rectal gland of dogfish, Squalus acanthias. |
title_sort |
elasmobranch rectal gland cell: autoradiographic localization of [3h]ouabain-sensitive na, k-atpase in rectal gland of dogfish, squalus acanthias. |
publisher |
Rockefeller University Press |
publishDate |
1979 |
url |
http://dx.doi.org/10.1083/jcb.83.1.16 https://rupress.org/jcb/article-pdf/83/1/16/1636367/16.pdf |
genre |
spiny dogfish Squalus acanthias |
genre_facet |
spiny dogfish Squalus acanthias |
op_source |
The Journal of cell biology volume 83, issue 1, page 16-32 ISSN 0021-9525 1540-8140 |
op_doi |
https://doi.org/10.1083/jcb.83.1.16 |
container_title |
Journal of Cell Biology |
container_volume |
83 |
container_issue |
1 |
container_start_page |
16 |
op_container_end_page |
32 |
_version_ |
1800740410095566848 |