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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 (Group 1A).Notes: Please note that in the third segment (S3) of the proximal tubule a few open lateral spaces between the cells can be seen (see arrows). H indicates the ascending branch of the loop of Henle. The scale bar represents 25 μm.
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f7-ijnrd-4-073: A PAS-stained, freeze-substituted normal kidney (Group 1A).Notes: Please note that in the third segment (S3) of the proximal tubule a few open lateral spaces between the cells can be seen (see arrows). H indicates the ascending branch of the loop of Henle. The scale bar represents 25 μm.

Mentions: In the S3 segments from normal, freeze-substituted kidneys, a slight extracellular space could be seen between the lateral cell membranes of some of the S3 cells (see Figure 7). After exposure to an acute heavy salt loading (Group 2C), a systematic and significant dilatation of the lateral intercellular space was noted (see Figure 8). In the later controls (Groups 2D–F) made 2 days, 2 weeks, and 4 weeks following the acute heavy salt loading, this change in cellular structure was found to normalize (see Figure 9).


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 (Group 1A).Notes: Please note that in the third segment (S3) of the proximal tubule a few open lateral spaces between the cells can be seen (see arrows). H indicates the ascending branch of the loop of Henle. The scale bar represents 25 μm.
© Copyright Policy
Related In: Results  -  Collection

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

f7-ijnrd-4-073: A PAS-stained, freeze-substituted normal kidney (Group 1A).Notes: Please note that in the third segment (S3) of the proximal tubule a few open lateral spaces between the cells can be seen (see arrows). H indicates the ascending branch of the loop of Henle. The scale bar represents 25 μm.
Mentions: In the S3 segments from normal, freeze-substituted kidneys, a slight extracellular space could be seen between the lateral cell membranes of some of the S3 cells (see Figure 7). After exposure to an acute heavy salt loading (Group 2C), a systematic and significant dilatation of the lateral intercellular space was noted (see Figure 8). In the later controls (Groups 2D–F) made 2 days, 2 weeks, and 4 weeks following the acute heavy salt loading, this change in cellular structure was found to normalize (see Figure 9).

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.