Adenine nucleotide metabolism by isolated kidney tubules during oxygen deprivation

Suspensions enriched in isolated rabbit proximal tubules were subjected to varying degrees of oxygen deprivation-induced injury by incubating them under hypoxic conditions at pH 7.4 or pH 6.6 or under high density pelleted conditions and adenine nucleotide degradation was characterized. The major metabolite was hypoxanthine. Its levels increased with the extent of irreversible injury. It was not further degraded or salvaged. Recovery of cell ATP during reoxygenation was predominantly from the remaining cell nucleotides. Allopurinol did not alter the pattern of purine metabolism or the extent of cell injury. These observations provide information on the intrinsic purine metabolic capacity of renal tubule cells during oxygen deprivation which is relevant to understanding both the salvage mechanisms available in these cells as well as the contribution of purine metabolism to the pathogenesis of oxygen deprivation-induced tubule cell injury.