Figure 6
From: In vivo imaging of kidney glomeruli transplanted into the anterior chamber of the mouse eye
10 kDa dextran is filtered by transplanted glomeruli and suggests the presence of a subpodocyte space.
(a–c) Injection of 2000 kDa dextran served to delineate the intravascular space. Simultaneous visualization of podocytes expressing CFP (blue fluorescence in b and c) reveals a small gap between the intravascular space and podocyte cell bodies (arrow in c). The faint red fluorescence within the outer aspect of podocytes (arrowheads in a) was present before injection of the 2000 kDa dextran and most likely results from endocytosis of labeled dextran from previous injections in the same mouse. (d–f) Injection of 10 kDa dextran in the same mouse ~10 minutes after injection of the 2000 kDa dextran reveals filtration of 10 kDa dextran into the subpodocyte space resulting in a double contour of glomerular capillaries (d; note that intravascular fluorescence in (d–f) represents the sum of the previously injected 2000 kDa dextran and the 10 kDa dextran). Filtered 10 kDa dextran fills the gap between the intravascular space and podocyte cell bodies (arrow in f). Only minimal fluorescence is visible outside the subpodocyte space directly after injection of the 10 kDa dextran (arrowhead in f vs. arrowhead in c) suggesting rapid dilution of the dextran once it leaves the subpodocyte space. (g) Quantification of the red (dextran) and blue (podocyte CFP) fluorescence intensities along a cross section of the capillary (dashed lines in panels c and f). Scale bars = 10 μm (a), (b), (d) and (e) or 5 μm (c) and (f).
