Levels of oxidized and reduced diphosphopyridine nucleotide and triphosphopyridine nucleotide in tumours

Abstract

The oxidized and reduced forms of di-and tri- phosphopyridine nucleotide were determined in a number of transplantable solid tumors and also in p-dimethylaminoazobenzene-induced liver tumors. Although liver from tumor-bearing rats has a normal diphosphopyridine nucleotide (DPN) content, the total triphosphopyridine nucleotide (TPN) content is less than 0.5 that of normal liver. In liver tumors, however, the concentration of both pyridine nucleotides is considerably reduced, total TPN being affected much more than total DPN. The total DPN contents of the solid transplantable tumors investigated are, in general, lower than those of most normal tissues. The total TPN contents are in all cases very low or negligible. The relative proportions of the oxidized and reduced forms of both pyridine nucleotides are not significantly different in normal and neoplastic tissues.