Androgen and estrogen stimulation of ornithine decarboxylase activity in mouse kidney

In the present work. the activity of mouse renal ornithine decarboxilase (O DC) from CBA female mice was used as a biological marker to detect (anti)an drogenic activity of different groups of endocrine disrupters and steroids. Daily injections of testosterone or dihydrotestosterone (DHT) into 60 day old Female mice for 1 days increased renal ODC activity in a dose-dependent manner that reached up to 100-fold (testosterone) or 250-fold (DHT) above the baseline when the highest dose, 200 mug/mouse, was used. Administration of flutamide concurrently with testosterone (75 mug/mouse) caused a potent decrease of ODC induction in a dose-dependent manner, suppressing the enzy me activity at the doses of 0.1 and 0.5 mg/mouse by about 88 and 95%, respe ctively. In contrast, estradiol at the doses of 0.5 and 1 mg/mouse induced a significant stimulation of renal ODC activity in a dose-dependent manner when it was given alone or in combination with testosterone. Using a sensit ive increase in ODC activity in response to androgens as an end point, we d id not detect an antiandrogenic effect of several antiandrogens, such as cy proterone acetate, spironolactone. p,p'DDE and vinclozolin. Also, none of t hese antiandrogens were able to change the basal level of renal ODC activit y, with the exception of cyproterone acetate that at a dose of 0.1 mg/mouse stimulated ODC activity. The data obtained suggest that mouse renal ODC fr om CBA females is not strictly androgen-specific and cannot be used for est imation of antiandrogenic effects of compounds having an affinity to differ ent types of receptors. (C) 2001 Elsevier Science Ltd. All rights reserved.