Enhanced urinary excretion of N1-acetylspermidine and the presence of tumors.

We have studied the urinary excretion of free and acetylated polyamines in hepatoma-bearing Buffalo rats during the period of linear growth of the tumor mass. The excretion of nonconjugated polyamines was unchanged. N1-Acetylspermidine excretion did not parallel the linear increase in tumor mass but increased exponentially. Enhancement of N8-acetylspermidine excretion above control levels was observed only at a time when the average tumor mass was 35 +/- 9 (S.D.) g. shortly before the period when necrosis is usually observed. These data taken together with the analysis of urinary acetylpolyamines in rats bearing mammary tumors and in two melanoma patients show that the determination of the N1-acetylspermidine/N8-acetylspermidine ratio in urine may be of only limited value as an indicator for the presence of tumors.