Diabetic SD rats were untreated or treated with PTHrP (1–34) by s.c. injection at 40, 80, or 160 μg/kg body weight for 3 months. (A) Representative microphotographs of fibronectin immunostaining (400 magnification) were shown. Computer-aided analysis of renal cortical fibronectin expressed as percent area (*P<0.05 vs control, #P<0.05 vs STZ group, n=5). (B) The protein level of fibronectin in renal cortex was detected by western blot, with GAPDH used as loading control (*P<0.05 vs control, #P<0.05 vs STZ group, n=8). (C) The protein levels of p47phox, phosphor-EGFR Y845, and phosphor-Akt S473 in renal cortex were detected by western blot, with GAPDH used as loading control (*P<0.05 vs control, #P<0.05 vs STZ group, n=8).