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Functionally induced changes in water transport in the proximal tubule segment of rat kidneys.

Faarup P, Holstein-Rathlou NH, Nørgaard T, Harrison AP, Bastholm L, Thatt L, Johansen FF, Hegedüs V - Int J Nephrol Renovasc Dis (2011)

Bottom Line: However, in the second segment, a special cellular phenomenon was constantly present, comprising a significant intercellular space that was easily identified using a light microscope.In the third segment, in which the presence of basolateral interdigitations is minimal, the small lateral space, which was found to be present in cryopreparations between neighboring cells from the normal kidney, was found to be enlarged by heavy salt loading of short duration.It is concluded that these cryotechniques demonstrate quantitative structural variations between superficial and deep nephrons, as well as the presence of extracellular areas between the cells of the second and the third segment, representing a structural background for the essential transport of water from the proximal tubules to the peritubular capillaries.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Sciences, Panum Institute University of Copenhagen.

ABSTRACT
To eliminate freezing artifacts in the proximal tubule cells, two cryotechniques were applied to normal rat kidneys, ie, freeze substitution and special freeze drying. In addition, salt depletion and salt loading were applied to groups of rats to evaluate whether the segmental structure of the proximal tubule could be altered. In the superficial part of the renal cortex of normal kidneys, the typical first segment structure in the proximal tubule was generally present in the early postglomerular fraction of the tubule. However, in the second segment, a special cellular phenomenon was constantly present, comprising a significant intercellular space that was easily identified using a light microscope. In the third segment, in which the presence of basolateral interdigitations is minimal, the small lateral space, which was found to be present in cryopreparations between neighboring cells from the normal kidney, was found to be enlarged by heavy salt loading of short duration. It is concluded that these cryotechniques demonstrate quantitative structural variations between superficial and deep nephrons, as well as the presence of extracellular areas between the cells of the second and the third segment, representing a structural background for the essential transport of water from the proximal tubules to the peritubular capillaries.

No MeSH data available.


A PAS-stained freeze-substituted normal kidney showing a juxtamedullary nephron.Notes: The cells in the proximal tubular loop (X), descending from the glomerulus, have a typical S2-like structure. The scale bar represents 25 μm.
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f5-ijnrd-4-073: A PAS-stained freeze-substituted normal kidney showing a juxtamedullary nephron.Notes: The cells in the proximal tubular loop (X), descending from the glomerulus, have a typical S2-like structure. The scale bar represents 25 μm.

Mentions: The present study, which is based on two different cryotechniques, makes possible an entirely new evaluation of the structural background underpinning the considerable water transport that occurs between proximal tubular cells and capillaries (Figures 1–5, 7, and 8). The validity of these newly observed structural details is supported by the fact that the two different cryotechniques used, ie, freeze substitution and special freeze drying, demonstrate identical morphology between similar cell types.


Functionally induced changes in water transport in the proximal tubule segment of rat kidneys.

Faarup P, Holstein-Rathlou NH, Nørgaard T, Harrison AP, Bastholm L, Thatt L, Johansen FF, Hegedüs V - Int J Nephrol Renovasc Dis (2011)

A PAS-stained freeze-substituted normal kidney showing a juxtamedullary nephron.Notes: The cells in the proximal tubular loop (X), descending from the glomerulus, have a typical S2-like structure. The scale bar represents 25 μm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3108790&req=5

f5-ijnrd-4-073: A PAS-stained freeze-substituted normal kidney showing a juxtamedullary nephron.Notes: The cells in the proximal tubular loop (X), descending from the glomerulus, have a typical S2-like structure. The scale bar represents 25 μm.
Mentions: The present study, which is based on two different cryotechniques, makes possible an entirely new evaluation of the structural background underpinning the considerable water transport that occurs between proximal tubular cells and capillaries (Figures 1–5, 7, and 8). The validity of these newly observed structural details is supported by the fact that the two different cryotechniques used, ie, freeze substitution and special freeze drying, demonstrate identical morphology between similar cell types.

Bottom Line: However, in the second segment, a special cellular phenomenon was constantly present, comprising a significant intercellular space that was easily identified using a light microscope.In the third segment, in which the presence of basolateral interdigitations is minimal, the small lateral space, which was found to be present in cryopreparations between neighboring cells from the normal kidney, was found to be enlarged by heavy salt loading of short duration.It is concluded that these cryotechniques demonstrate quantitative structural variations between superficial and deep nephrons, as well as the presence of extracellular areas between the cells of the second and the third segment, representing a structural background for the essential transport of water from the proximal tubules to the peritubular capillaries.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Sciences, Panum Institute University of Copenhagen.

ABSTRACT
To eliminate freezing artifacts in the proximal tubule cells, two cryotechniques were applied to normal rat kidneys, ie, freeze substitution and special freeze drying. In addition, salt depletion and salt loading were applied to groups of rats to evaluate whether the segmental structure of the proximal tubule could be altered. In the superficial part of the renal cortex of normal kidneys, the typical first segment structure in the proximal tubule was generally present in the early postglomerular fraction of the tubule. However, in the second segment, a special cellular phenomenon was constantly present, comprising a significant intercellular space that was easily identified using a light microscope. In the third segment, in which the presence of basolateral interdigitations is minimal, the small lateral space, which was found to be present in cryopreparations between neighboring cells from the normal kidney, was found to be enlarged by heavy salt loading of short duration. It is concluded that these cryotechniques demonstrate quantitative structural variations between superficial and deep nephrons, as well as the presence of extracellular areas between the cells of the second and the third segment, representing a structural background for the essential transport of water from the proximal tubules to the peritubular capillaries.

No MeSH data available.