Age- and Cell-Specific Regulation of Testicular Polyamine Metabolism Promotes Increased Catabolism During Maturation and Aging in Syrian Hamsters.

No previous studies have characterized testicular polyamine metabolism across specific cell populations, including Sertoli cells, testicular peritubular cells, Leydig cells, germ cells, and testicular macrophages, during testicular maturation and aging. Here, we used immature, young adult, and aged adult Syrian hamsters as an animal model to quantify the main polyamines (PA) and their monoacetylated derivatives at the tissue and cellular levels by thin-layer chromatography and to assess the expression profiles of key genes involved in polyamine metabolism by RT-qPCR. At the tissue level, total PA concentration increased with age. During testicular maturation, putrescine increased and spermine decreased, whereas aged testes showed spermidine predominance. Testicular cell populations contributed unequally to PA production and release, and these contributions changed markedly with age. At the cellular level, aging was associated with a shift toward spermine- and N1-spermine-rich profiles, suggesting enhanced PA catabolism, likely supported by Sat1/Paox up-regulation. Thus, PA catabolic enzymes represent potential therapeutic targets for aging-associated or even idiopathic infertility-related testicular alterations.