Viability estimation of preserved dog kidneys based on the LDH activity in the preservation perfusate

The lactate dehydrogenase (LDH) activity and LDH isozyme ratio in the perfusate were investigated in perfused dog kidneys, preserved from dogs subjected to warm ischemia of varying duration prior to kidney removal. The length of this warm ischemic time exerted a marked effect on the variations in both the LDH activity and isozyme ratio. Moreover, the variations in LDH activity and isozyme ratio during the preservation were found to correlate well. On this basis, the M-component activity of the LDH isozymes and the activity of the LDH4 and LDH5 isoenzymes are proposed to represent more sensitive parameters for evaluating the tissue hypoxic damage. Our data were also analyzed retrospectively, in relation to the ability of the perfused kidney to function on autotransplantation. It was found that the amount of LDH4 and LDH5 isoenzyme activity was of great value in determining the viability of the kidney. Thus, an analysis of the LDH activity in the wash solution can provide considerable and precise information about the kidney viability as a graft.