Effects of treatments on protein expressions of TGF-β1 and fibronectin in renal tissues of rats. (A) Immunohistochemical staining for TGF-β1 and fibronectin in renal tissues of STZ-diabetic rats treated for eight weeks with ruscogenin (RUS) or rosiglitazone (Rosi). STZ-diabetic rats were dosed by oral gavage once daily for eight weeks with 3 mg/kg RUS (STZ + RUS) or 5 mg/kg RGZ (STZ + Rosi). Normal (normal + Veh) or STZ-diabetic rats receiving vehicle treatment (STZ + Veh) were administered the same volume of vehicle (Veh) used to prepare test medications. Arrows indicate positive areas. Magnification bars = 50 μm. (B) Semi-quantitative assessments of the immunostaining were scored using 4 levels, and an average value was obtained from analyses of more than 30 glomeruli per rat. Values (mean ± SD) were obtained for each group of 5 animals. bP < 0.01 compared to vehicle-treated normal rats (normal + Veh). cP < 0.05 and dP < 0.01 compared to vehicle-treated STZ-diabetic rats (STZ + Veh), respectively.