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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.


An enlarged region of Figure 2a. Please note the net-like structure in the nuclear content connecting the nucleolus to the nuclear membrane of the S1 cell (see arrows). The scale bar represents 25 μm.
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f2b-ijnrd-4-073: An enlarged region of Figure 2a. Please note the net-like structure in the nuclear content connecting the nucleolus to the nuclear membrane of the S1 cell (see arrows). The scale bar represents 25 μm.

Mentions: The most important structural difference found in both types of cryopreparations was the consistent presence of an essential extracellular space between the basolateral membranes of typical S2-like cells of the proximal convoluted tubule. Although the cell nuclei of the S1 and S3 cells were always oval or circular in shape, the S2 cell nuclei were frequently angular in appearance, presumably as a consequence of the dilated intercellular space found between the S2 cells (Figures 1, 2, and 4). In the nuclei of the proximal tubule, a special structural phenomenon could be observed, most easily seen in S1-like cells. Here, the nuclear content demonstrated a ramified network, typically connecting the nucleolus to the nuclear membrane (Figure 2B). A similar nuclear network was sometimes found in the nuclei of the endothelial cells of the peritubular capillaries.


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)

An enlarged region of Figure 2a. Please note the net-like structure in the nuclear content connecting the nucleolus to the nuclear membrane of the S1 cell (see arrows). The scale bar represents 25 μm.
© Copyright Policy
Related In: Results  -  Collection

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

f2b-ijnrd-4-073: An enlarged region of Figure 2a. Please note the net-like structure in the nuclear content connecting the nucleolus to the nuclear membrane of the S1 cell (see arrows). The scale bar represents 25 μm.
Mentions: The most important structural difference found in both types of cryopreparations was the consistent presence of an essential extracellular space between the basolateral membranes of typical S2-like cells of the proximal convoluted tubule. Although the cell nuclei of the S1 and S3 cells were always oval or circular in shape, the S2 cell nuclei were frequently angular in appearance, presumably as a consequence of the dilated intercellular space found between the S2 cells (Figures 1, 2, and 4). In the nuclei of the proximal tubule, a special structural phenomenon could be observed, most easily seen in S1-like cells. Here, the nuclear content demonstrated a ramified network, typically connecting the nucleolus to the nuclear membrane (Figure 2B). A similar nuclear network was sometimes found in the nuclei of the endothelial cells of the peritubular capillaries.

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.