Aminoguanidine Supplementation Delays the Onset of Senescence In Vitro in Dermal Fibroblast-Like Cells From Senescence-Accelerated Mice

The effects of aminoguanidine supplementation on senescence acceleration in vitro were examined in fibroblasts from the dorsal dermis of newborn SAMP II (accelerated senescence-prone mice), and were compared to the effects in cell lines from SAMRI (accelerated senescence-resistant) mice. Four millimow aminoguanidine supplementation signijicantly de­ layed the senescencelcrisis in eel/lines from SAMP 11 mice, but did not affect the senescencelcrisis in cell lines from SAMRI mice. Flow cytometric analysis of the DNA content of confluent cells revealed that aminoguanidine supplementa­ tion signijicandy decelerated the increase in the number of tetraploid cells until senescencelcrisis. Although mean concen­ trations of lipid peroxides in the primary cultures did not differ signijicantly, considerably higher lipid peroxidatWn was ob­ served in some SAMPll cultures, and aminoguanidine supplementation reduced them to the levels in SAMRI cultures. These results strongly suggest that oxidative stress derivedfrom polyamine catabolism may contribute to the senescence ac­ celeration in vitro in eel/lines from SAMPII mice.