Postischemic diagnostic localization of tubular lesions

Several functional parameters were applied in an experimental model of ischemia to test the ability to localize the distribution of tubular lesions. Canine kidneys were perfused with protective solutions and rendered ischemic for definite periods. Renal function was determined during a subsequent 3-h reperfusion. The pattern and the extent of renal injury were influenced by varying the duration of ischemia and by modifying the protective solution used. The results suggest that by employing an appropriate selection of parameters it is possible to allocate renal injury to definite sections of the tubules. According to such an evaluation, under protection with HTK-solution, the proximal tubule limits the tolerance of renal ischemia. The thick ascending limb shows some vulnerability that is aggravated by disadvantageous modifications of the protective solution and that may become more pronounced in the course of reperfusion. In contrast, more distal parts of the nephron retain a remarkable reserve transport capacity after a tolerable level of ischemia.