Plasma IL-6, plasma NGAL, and urine NGAL were determined in normal (unmanipulated) mice, and after sham, ischemic AKI or BNx at 4 and 24 hours in wild type (WT) and IL-6−/− mice. Plasma IL-6 was increased in WT 4 and 24 hours after (A) sham, (B) AKI, and (C) BNx. Plasma NGAL was significantly reduced in IL-6−/− at 4 and 24 hours after (D) sham, (E) AKI and (F) BNx. Urine NGAL was reduced after sham and ischemic AKI in IL-6−/− (G-J). N=3 to 12 mice per group from 3 experiments. Results are expressed as mean ±SEM and analyzed by t test: WT versus IL-6−/− at the same time point (indicated above the bar) and versus normal WT (indicated below the bar: *P<0.05; **P<0.01, ***P < 0.0001).