Figure 5.

Mesangial and histological assessment of the kidneys showing severe mesangial expansion in ob/ob mice, and the effect of Vitamin D₃ in glomerular damage and in acute tubular necrosis. (A) PAS staining of glomeruli from C57BL/6 and from ob/ob mice after Vitamin D₃ stimulation (+) or after saline injection (−). Bars = 20 µm. (B) VitD₃ promoted increased matrix deposition in mesangial compartment of C57BL/6 mice that was able to reach ob/ob levels (no statistical difference among VitD₃-treated C57BL/6 and VitD₃-treated ob/ob mice). (C) Increased glomerular area in ob/ob mice. There was no additive effect of Vitamin D₃ in ob/ob mice, but VitD₃ was able to equalize glomerular area in C57BL/6 and in ob/ob mice. α, β, γ, δ = P < 0.05, in comparison to saline-treated C57BL/6 (n = 9), VitD₃-treated C57BL/6 (n = 7), saline-treated ob/ob (n = 7), and VitD₃-treated ob/ob mice (n = 8), respectively. (D) Vitamin D₃ induced acute tubular necrosis (ATN) both in C57BL/6 and in ob/ob mice, as shown by flattening of the renal tubular cells due to tubular dilation (asterisks), loss of brush border (arrows), and degenerative changes characterized by diffuse denudation of the renal cells, presence of necrotic cells, and cellular debris. Insert depicts degenerative changes in a distal tubule. Bars = 20 µm. For saline-injected mice n = 4–6, and for Vitamin D₃–treated mice, n = 5–8.