Energy restriction and testosterone implants alter ornithine decarboxylase gene expression in kidney of female rats.

Effects of testosterone and energy restriction (30%) on enzyme activity and mRNA level of ornithine decarboxylase (ODC) were studied in 19-wk-old female Sprague-Dawley rats. Testosterone implantation for 1 wk elicited a sixfold increase in ODC activity and a fourfold increase in ODC mRNA transcripts in the kidney. Energy restriction also increased renal ODC activity. Further, the 56% increase in ODC enzyme activity observed in the testosterone-implanted, energy-restricted group was greater than the 24% increase in the placebo-implanted, energy-restricted group. No changes in renal ODC mRNA levels were observed in the energy-restricted groups. These observations suggest that translational or post-translational mechanism(s) are involved in the greater renal ODC activity in energy-restricted rats.