Fig. 4

Renal cortical sections stained with Hematoxylin-eosin (a, b), immunostained for caspase 9 (c, d) and stained with Masson’s trichrome (e, f). The sections were obtained from vehicle-treated (control—1 h) rats (a, c, e) and 15 min (b) and 7 days (d, f) after intravenous injection of rGO. Note that there is no change between the aspect of control and rGO-treated sections in each of the staining assessments. The widening of the tubular lumen and capsular space was observed in control and rGO samples due to perfusion fixation. Insets depict that collagen density (just in large blood veins of renal stroma) was the same for control and rats treated with rGO. 1 Renal glomeruli; 2 proximal tubule; 3 distal tubule; 4 collecting tubule; * Bowman’s space of the renal corpuscle. Arrows point to the immuno-positive apoptotic cells (brown). Bars 100 µm for all panels