The route of passive chloride movement across amphibian skin: localization and regulatory mechanisms
Transepithelial Cl − conductance ( G Cl) in amphibian skin can be activated in several species by serosa positive potentials. Mitochondria-rich cells (MRC) or tight junctions (TJ) between the epithelial cells are possible sites for this pathway. The properties and the techniques used to investigate...
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Published in | BBA - Biomembranes Vol. 1566; no. 1; pp. 44 - 54 |
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Main Authors | , , |
Format | Book Review Journal Article |
Language | English |
Published |
Netherlands
Elsevier B.V
13.11.2002
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Subjects | |
Online Access | Get full text |
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Summary: | Transepithelial Cl
− conductance (
G
Cl) in amphibian skin can be activated in several species by serosa positive potentials. Mitochondria-rich cells (MRC) or tight junctions (TJ) between the epithelial cells are possible sites for this pathway. The properties and the techniques used to investigate this pathway are reviewed in the present paper. In situ techniques are preferable, since specific properties of the MRC are apparently not maintained in isolated cells. Volume measurements and electronprobe microanalysis of intracellular ions suggest the localization of voltage-activated
G
Cl to MRC.
G
Cl correlates poorly with the density of MRC. The vibrating voltage probe allows quantitative correlation of the local Cl
− current through morphologically identified structures and the transepithelial Cl
− current. Our analysis shows that 80% of the voltage-activated Cl
− current is accounted for by current through MRC or their immediate vicinity. The activation patterns of this current and the inhibition by the α
1-adrenergic agonist, epinephrine, conform to those of the transepithelial current. However, less than 20% of the MRC are active at a certain moment and the activity is spontaneously variable with time. The molecular nature of this pathway, physiological control mechanisms and their relation to the temporal activity of MRC remain to be studied. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-3 content type line 23 ObjectType-Review-1 |
ISSN: | 0005-2736 0006-3002 1879-2642 |
DOI: | 10.1016/S0005-2736(02)00593-X |