In situ detection of lipid peroxidation by-products as markers of renal ischemia injuries in rat kidneys

Purpose: Lipid peroxidation is an autocatalytic mechanism leading to oxidat ive destruction of cellular membranes. In renal transplantation, this mecha nism is triggered by ischemia/reperfusion and may be of relevance in graft failure. Materials and Methods: Using specific antibodies directed against malondial dehyde (MDA) and 4-hydroxynonenal (HNE) adducts, major aldehydic metabolite s of lipid peroxidation, we investigated, in situ, by means of an immunohis tochemical procedure, the occurrence of lipid peroxidation during different warm ischemic periods of 0, 15, 30, 45 and 60 minutes in rat kidneys prior to reperfusion, The same experiments included followup of the rats after n ephrectomy and reperfusion for 10 days. Results: We observed superficial and deep cortex immunostaining with both a ntibodies against MDA and HNE after 30 minutes of warm ischemia, This immun ostaining was observed in the absence of any histological lesions, as asses sed by routine staining. After 45 and 60 minutes of warm ischemia, lipid pe roxidation byproducts were detected both in the cortex and in the medulla, which is associated with 33% and 66% of rat deaths respectively. Conclusions: This study confirms the involvement of the lipid peroxidation process in kidney damage during anoxia before reperfusion, and its extensio n to the whole organ. Lipid peroxidation byproducts were detectable in warm ischemic kidney, and the presence of medulla immunostaining was associated with the animals' death. Lipid peroxidation immunostaining might thus be u seful as a sensitive tool to detect ischemic damage after warm ischemia pri or to reperfusion, as well as in the decision to carry out kidney transplan tation in humans.