Androgen modulation of ornithine decarboxylase and compensatory renal growth.

This report presents a comparative study of the activity of ornithine decarboxylase (ODC) (L-ornithine carboxylase EC 4.1.1.17) in male and female mice and rats and the correlations between ODC, androgens and compensatory renal growth (CRG). We have found that existing levels of renal ODC activity at the onset of renal regeneration following a uninephrectomy play a determining role in the extent of CRG. Basal ODC activity varies according to species and sex, being three times higher in male than in female mice but equal in all rats; an analogous sexual dimorphism also exists in the degree of CRG. The injection of 5 alpha-dihydrotestosterone, which can stimulate ODC activity in mice and rats, is also able to induce a higher degree of CRG. Our results seem to indicate that androgens can influence CRG by modulating renal ODC and that this response to androgen may also vary with species.