Figure 6

Vitamin D₃-treated Npt2a^−/− mice show signs of impaired kidney function and greater renal Ca²⁺-P_i deposits. (a) Plasma creatinine levels were the highest in vitamin D₃-treated Npt2a^−/− mice. (b) Similarly, urinary albumin/creatinine ratios showed the biggest increase compared to baseline in vitamin D₃-treated Npt2a^−/− mice. (c) Histological classification of mineral deposits in genotypes with vehicle or vitamin D₃ treatment. The majority of vehicle-treated WT mice show no mineral deposits, vehicle-treated Npt2a^−/− mice showed mild deposits (< 10%), vitamin D₃-treated WT showed greater severity (moderate 10–50%) and only some vitamin D₃-treated Npt2a^−/− mice showed the greatest number of deposits (> 50%). Representative examples of H&E and von Kossa staining are shown for each condition from mice with no mineral deposits (d), mild deposits (e), moderate deposits (f) and severe deposits (g). Von Kossa staining shows that Ca²⁺-P_i crystal deposits (black stains) localize within the tubular lumen. The tubules show evidence of damage with attenuation of the epithelial lining. Magnification × 200. Scale bar of 100 µm is shown in each image. Male and female mice were used in these studies. In addition to single data summary data are shown and are expressed as mean ± SEM and were analyzed by two-way ANOVA followed by the two-stage linear step-up procedure of Benjamini, Krieger, and Yekutieli. *P < 0.05 vs WT same treatment, ^§P < 0.05 vs vehicle same genotype.