Postnatal development of ornithine decarboxylase and polyamines in the mouse kidney: influence of testosterone.

The role of ornithine decarboxylase (ODC) and polyamines in kidney growth during the postnatal development of mice and the influence of testosterone were investigated. A marked sexual dimorphism in renal size was evident after the 3rd week of life, corresponding with the rise in circulating testosterone and the increase in renal ODC and urinary excretion of putrescine in male mice. Renal putrescine and spermidine gradually decreased during the first 3 weeks of life and did not correlate with ODC activity. Treatments with alpha-difluoromethylornithine, and ODC-specific inhibitor, and the antiandrogen flutamide during weeks 4 and 5 showed that both compounds decreased renal ODC activity but only flutamide impaired kidney growth, suggesting that renal growth in mice is regulated by androgens but is independent of the induction of ODC activity.