BACKGROUND:Recent studies have identified T cells and natural killer T (NKT) cells as important mediators in renal ischemia-reperfusion (I/R) injury. The recruitment of these cells is induced by chemotaxis factors. We investigated the effects of blocking CXCR3 and CCR5 by an antagonist (TAK) using a rat renal I/R injury model. METHODS:The Sprague-Dawley rats were either subjected to sham operation or left renal occlusion for 45 min followed by reperfusion and contralateral nephrectomy. The control or TAK groups were, respectively, injected phosphate-buffered saline or TAK at 30 min prior to clamp. Serum creatinine, tubular injury, chemokines expression and infiltrating cells were assessed. RESULTS:TAK treatment significantly suppressed the elevation in serum creatinine (sham 0.40 ± 0.05 mg/dL, control 2.86 ± 0.67 mg/dL, TAK 1.60 ± 0.73 mg/dL) and resulted in a lower tubular injury score compared with the control group (sham 0, control 4.8 ± 0.3, TAK 3.3 ± 1). The mRNA expression of chemokines that bind to CXCR3 and CCR5 in the post-ischemic kidneys was elevated at 1 h after reperfusion in each group. Moreover, the infiltration of CD4+ T cells and CD8+ NKT cells in the control group increased compared with the sham group and TAK injection significantly suppressed the number of CD4+ T cells (sham 13.5 ± 3.5 × 10(4) cells, control 28.9 ± 15.4 × 10(4) cells, TAK 11.8 ± 3.5 × 10(4) cells) and the number of CD8+ NKT cells (sham 11.7 ± 5.4 × 10(4) cells, control 30.1 ± 8.6 × 10(4) cells, TAK 11.8 ± 2.9 × 10(4) cells). CONCLUSIONS:These findings suggest that the blocking of CXCR3 and CCR5 suppress the infiltration of T cells and NKT cells and have a protective effect on kidneys that are injured by I/R.