FUR in ischemic and non-ischemic kidneys before and following unilateral warm ischemia of 40 min. It is presented with corresponding histological sections. (A) Compared with the baseline, FUR calculation detected a significant decrease in kidney function both 8 and 14 days following severe ischemia. (B) Contralateral non-ischemic kidneys showed no significant changes in FUR after injury. (C) Ischemic kidneys exhibited structural changes as signs of hypoxia without any evidence for necrosis and inflammatory infiltration, respectively. (D) In the contralateral non-ischemic kidneys, no structural damage was found.