Ornithine decarboxylase activity as a marker of androgen and antiandrogen action in the rat epididymis
After castration, there was a marked decrease in serum androgen concentration at 6 h, and a dramatic inhibition of ornithine decarboxylase (ODC) at 12 h. Administration of testosterone propionate to castrated rats at a dose of 0.05 mg/animal restored ODC activity to the normal value. However, no cha...
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1988
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00224251_v83_n1_p177_DeLasHeras http://hdl.handle.net/20.500.12110/paper_00224251_v83_n1_p177_DeLasHeras |
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paper:paper_00224251_v83_n1_p177_DeLasHeras2023-06-08T14:50:53Z Ornithine decarboxylase activity as a marker of androgen and antiandrogen action in the rat epididymis androgen flutamide ornithine decarboxylase testosterone propionate animal experiment castration epididymis male nonhuman rat Animalia After castration, there was a marked decrease in serum androgen concentration at 6 h, and a dramatic inhibition of ornithine decarboxylase (ODC) at 12 h. Administration of testosterone propionate to castrated rats at a dose of 0.05 mg/animal restored ODC activity to the normal value. However, no change was observed when intact rats were treated with testosterone even at a 40-fold higher dose, indicating that endogenous androgens present in intact rats are far in excess for maintenance of maximal levels of activity. Administration of the antiandrogen flutamide to intact rats caused a moderate decrease in epididymal weight, whereas this effect was more pronounced in castrated, androgen-treated rats. In the latter, the effect of flutamide was significant at the lowest dose used (0.5 mg/day). ODC activity was significantly decreased by flutamide treatment of intact rats, but even at the highest dose used (10 mg/day) only a 39% inhibition was observed. In flutamide-treated rats, LH concentrations were markedly increased, as were serum and epididymal androgens. In androgen-treated castrated rats, flutamide caused epididymal ODC to fall to undetectable values. These results show that: (1) androgens are essential for the maintenance of ODC activity in the epididymis; (2) epididymal ODC activity is maximally stimulated by endogenous androgens, at least in the pubertal rat; (3) the apparent potency of flutamide is substantially lowered by an increase in epididymal androgens. We suggest that ODC is a sensitive marker of the action of androgens and antiandrogens in the epididymis. 1988 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00224251_v83_n1_p177_DeLasHeras http://hdl.handle.net/20.500.12110/paper_00224251_v83_n1_p177_DeLasHeras |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
androgen flutamide ornithine decarboxylase testosterone propionate animal experiment castration epididymis male nonhuman rat Animalia |
| spellingShingle |
androgen flutamide ornithine decarboxylase testosterone propionate animal experiment castration epididymis male nonhuman rat Animalia Ornithine decarboxylase activity as a marker of androgen and antiandrogen action in the rat epididymis |
| topic_facet |
androgen flutamide ornithine decarboxylase testosterone propionate animal experiment castration epididymis male nonhuman rat Animalia |
| description |
After castration, there was a marked decrease in serum androgen concentration at 6 h, and a dramatic inhibition of ornithine decarboxylase (ODC) at 12 h. Administration of testosterone propionate to castrated rats at a dose of 0.05 mg/animal restored ODC activity to the normal value. However, no change was observed when intact rats were treated with testosterone even at a 40-fold higher dose, indicating that endogenous androgens present in intact rats are far in excess for maintenance of maximal levels of activity. Administration of the antiandrogen flutamide to intact rats caused a moderate decrease in epididymal weight, whereas this effect was more pronounced in castrated, androgen-treated rats. In the latter, the effect of flutamide was significant at the lowest dose used (0.5 mg/day). ODC activity was significantly decreased by flutamide treatment of intact rats, but even at the highest dose used (10 mg/day) only a 39% inhibition was observed. In flutamide-treated rats, LH concentrations were markedly increased, as were serum and epididymal androgens. In androgen-treated castrated rats, flutamide caused epididymal ODC to fall to undetectable values. These results show that: (1) androgens are essential for the maintenance of ODC activity in the epididymis; (2) epididymal ODC activity is maximally stimulated by endogenous androgens, at least in the pubertal rat; (3) the apparent potency of flutamide is substantially lowered by an increase in epididymal androgens. We suggest that ODC is a sensitive marker of the action of androgens and antiandrogens in the epididymis. |
| title |
Ornithine decarboxylase activity as a marker of androgen and antiandrogen action in the rat epididymis |
| title_short |
Ornithine decarboxylase activity as a marker of androgen and antiandrogen action in the rat epididymis |
| title_full |
Ornithine decarboxylase activity as a marker of androgen and antiandrogen action in the rat epididymis |
| title_fullStr |
Ornithine decarboxylase activity as a marker of androgen and antiandrogen action in the rat epididymis |
| title_full_unstemmed |
Ornithine decarboxylase activity as a marker of androgen and antiandrogen action in the rat epididymis |
| title_sort |
ornithine decarboxylase activity as a marker of androgen and antiandrogen action in the rat epididymis |
| publishDate |
1988 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00224251_v83_n1_p177_DeLasHeras http://hdl.handle.net/20.500.12110/paper_00224251_v83_n1_p177_DeLasHeras |
| _version_ |
1768543979269259264 |