Correlation of polyamines, acrolein-conjugated lysine and polyamine metabolic enzyme levels with age in human liver

The polyamines spermidine, spermine and putrescine are essential for normal cellular functions. The contents of polyamines in tissue decreased in aged mice compared to young mice. In this study, the polyamine contents and their metabolic byproduct acrolein-conjugated lysine (N-epsilon-(3-formyl-3,4-dehydropiperidino)-lysine, FDP-Lys) in human liver tissue were measured and analyzed the correlation with age of the subjects. The putrescine and FDP-Lys levels were significantly increased with age. On the other hand, spermine level was decreased with age. Spermidine did not significantly correlate with age. The relative amount of spermine oxidase (SMOX) significantly correlated with the age of subjects whereas ornithine decarboxylase (ODC) and adenosylmethionine decarboxylase (AMD1) significantly reduced by the age. Our results suggested that an increase in oxidation and reduction in polyamine synthesis may cause the change of polyamine profile in the elderly.