AC administration prior to moderate and mild renal IRI impaired renal function. Renal IRI was induced in 8-week old male Balb/c mice by a right nephrectomy and ischaemia induced by occlusion of the left renal pedicle. Sham mice underwent a laparotomy only. Either PBS or 20×106 early or late ACs were administered 24 hr prior to mild (20 mins ischaemia), moderate (24 mins) or severe (25 mins) ischaemic injury. Mice were sacrificed 24 hr following IRI. (A) Administration of early ACs did not preserve renal function from severe IRI. (B) In contrast, administration of late ACs significantly worsened renal function in mice with moderate IRI. (C) Similarly, early ACs administered prior to mild ischaemia significantly worsened renal function. Analysed by one-way ANOVA or students t-test * = P ≤ 0.05, ns = non-significant. Sham (n = 4), PBS (n = 7–8), AC (n = 8).