Fig 1.
Glomerular maturity stages found in the neonatal rabbit kidney.
Stages are based on criteria previously defined [13–15]. Glomeruli were divided in either immature stages (A-C) or mature stages (D-F). (A) Vesicle (V): a cluster of mesenchymal cells, exclusively found in the nephrogenic zone, bordering a ureteric bud (UB). (B) Comma- or S-shaped body: formed by the elongation and twisting of the vesicle. (C) Capillary loop: The lower limb of the S-shaped body formed an immature glomerulus, characterized by a crescent shape and few capillaries. (D) Stage I: no lobulation and at least half of the circumference is lined with dark-staining podocytes. (E) Stage II: little lobulation and less than half of the circumference is covered with dark-staining podocytes. Some open capillaries may be seen. (F) Stage III: fully matured glomerulus showing full lobulation and open capillaries. No podocytes lining the glomerular tuft. (Bar = 50 μm).
Fig 2.
(A): Visual illustration of the animal model. Time points highlighted in blue are harvesting time points. (B): A graphic overview of the total immature and mature stage glomeruli across G28, G28 + 7 and G31 + 4, in absolute [mean] and relative counts [mean / %].
Fig 3.
(A) Glomerular cross-sections counted. (** = p < 0.001. Error bars: mean ± SD) (B-F) Correlations plotted using Spearman’s Rank-Order correlation on glomerular cross-sections and the following variables: bodyweight, kidney volume, kidney weight, and renal corpuscle surface area for the inner and outer cortex. Best-fit slope (solid line) is accompanied by a 95%-CI (dotted line).
Table 1.
Distribution of maturity stages.
Stages presented by the absolute mean, 95% confidence intervals and as the percentage of the total glomerular cross-sections counted.
Fig 4.
Visual representation of the functional parameters measured: urinary creatinine, protein and the protein/creatinine ratio. Comparison between G28 + 7 and G31 + 4 reveals significant differences in proteinuria and in the protein/creatinine ratio. (* = p < 0.05. Error bars: mean ± SD).