Fig. 1

Biochemical and histological assessment of renal function and structure in the different studied groups. A, B Serum creatinine (A) and serum urea (B) levels. C–H H&E staining for the sham group (C) and FA group (D) showing the renal corpuscle, closely packed renal proximal tubules, and distal convoluted tubule. The glomerulus appeared normal and was surrounded by the thin-walled parietal layer of the Bowman capsule with no retraction of the tuft. The brush border of the tubules is seen intact (blue arrow) with a thin basement membrane. IR group (E, F) showing the glomerulus surrounded by the thickened parietal layer of Bowman’s capsule and retraction of the glomerular tuft. Most of the tubules are disrupted, showing a thickened basement membrane with loss of brush border (blue arrow) in more than 25% of the tubules with shedding of tubular cells (red arrow) and hyaline cast formation. Vacuolations are also seen in many tubules (blue star) with small dark pyknotic nuclei (yellow arrow). The interstitium is widened by necrotic cells and congested capillaries in up to 60% of the tissues. The endothelial cells are swollen (thick black arrow). FA-IR group (G, H) showing the glomerulus with a thin parietal layer of Bowman’s capsule and no retraction in the glomerular tuft. The proximal and distal tubules are closely packed in most of the fields, showing preserved brush borders (blue arrow) and thin basement membranes. There is loss of brush border in less than 25% of the tubules. The interstitial space appears with hemorrhage in less than 25% of the tissues. Some tubules appeared with cytoplasmic vacuolations (blue star) and small dark pyknotic nuclei (yellow arrow). The endothelium is intact with flat nuclei (thick black arrow). I–K Graphical summary for some features of kidney injury, mean of area percentage filled with collagen (I), thickness of basement membrane (J), width of Bowman’s space (K). Values are expressed as the mean ± SEM. ns: nonsignificant, **p < 0.01, ****p < 0.0001, [P] proximal tubules, [D] distal convoluted tubule, [G] glomerulus, [*] Bowman’s capsule, [↑] capillary tuft, [▲] basement membrane, [C] capillaries, [I] renal interstitium. Scale bar is 50 µm