Western blot of GRP78 (A), total and phosphorylated-PERK (B), ATF4 (C) and TRAF2 (D) protein levels. The upper panels show one representative blot of six independent experiments and the lower panels show densitometric analysis. Sham group: rats underwent only dissection; I/R group: renal pedicles underwent 60 min of warm ischemia (I) followed by 120 min of reperfusion (R). IPC group: renal pedicles underwent 2 cyles of 5 min of I and 5 min of R, just before sustained I. L-NAME+IPC group: 5 min before IPC, 5 mg/kg of NG-nitro-L-arginine methylester (L-NAME) was intravenously administered. Results are presented as mean ± SEM (n = 6 in each group). *P < 0.05 vs. Sham group, #P < 0.05 vs. I/R group, +P < 0.05 vs. IPC group.