The aim of the present experiments was to analyze whether the inhibitory effect exerted by testosterone on FSH release might be mediated by the intracerebral transformation of the hormone into oestrogenic metabolites. Advantage has been taken of the availability of the potent antioestrogen tamoxifen. Two series of experiments have been performed. In the first one, adult male rats have been castrated and submitted, beginning immediately after surgery, to a 6-day treatment with testosterone propionate (2 mg/rat/day), tamoxifen (50 or 200 micrograms/rat/day) or testosterone propionate (2 mg/rat/day) plus tamoxifen (either 50 or 200 micrograms/rat/day). In the second experiment, adult male rats have been castrated and submitted to the same 6-day treatments, beginning 4 weeks following orchidectomy. In both experiments, the animals were killed 24 h after the last injection, and serum levels of FSH and LH have been measured by radioimmunoassays. The results have clearly shown that, in both experiments, the administration of testosterone results in a significant decrease of serum FSH and in a total suppression of LH release. The administration of tamoxifen, in either dose, does not modify the elevated serum FSH and LH levels present in the orchidectomized animals, and does not antagonize the inhibitory effect on FSH and LH secretion exerted by the concomitant treatment with testosterone propionate. It is concluded that testosterone inhibits FSH secretion in orchidectomized rats acting as such, and not following aromatization to oestrogens.

Tamoxifen does not block the inhibitory effect of testosterone on FSH release in rats / P. Negri-Cesi, F. Celotti, R. C. Melcangi, M. Zanisi, M. Motta. - In: ACTA ENDOCRINOLOGICA. - ISSN 0001-5598. - 114:1(1987 Jan), pp. 84-89.

Tamoxifen does not block the inhibitory effect of testosterone on FSH release in rats

P. Negri-Cesi
Primo
;
F. Celotti
Secondo
;
R.C. Melcangi;M. Zanisi
Penultimo
;
M. Motta
Ultimo
1987

Abstract

The aim of the present experiments was to analyze whether the inhibitory effect exerted by testosterone on FSH release might be mediated by the intracerebral transformation of the hormone into oestrogenic metabolites. Advantage has been taken of the availability of the potent antioestrogen tamoxifen. Two series of experiments have been performed. In the first one, adult male rats have been castrated and submitted, beginning immediately after surgery, to a 6-day treatment with testosterone propionate (2 mg/rat/day), tamoxifen (50 or 200 micrograms/rat/day) or testosterone propionate (2 mg/rat/day) plus tamoxifen (either 50 or 200 micrograms/rat/day). In the second experiment, adult male rats have been castrated and submitted to the same 6-day treatments, beginning 4 weeks following orchidectomy. In both experiments, the animals were killed 24 h after the last injection, and serum levels of FSH and LH have been measured by radioimmunoassays. The results have clearly shown that, in both experiments, the administration of testosterone results in a significant decrease of serum FSH and in a total suppression of LH release. The administration of tamoxifen, in either dose, does not modify the elevated serum FSH and LH levels present in the orchidectomized animals, and does not antagonize the inhibitory effect on FSH and LH secretion exerted by the concomitant treatment with testosterone propionate. It is concluded that testosterone inhibits FSH secretion in orchidectomized rats acting as such, and not following aromatization to oestrogens.
Rats, Inbred Strains; Rats; Animals; Testosterone; Luteinizing Hormone; Brain; Tamoxifen; Male; Orchiectomy; Follicle Stimulating Hormone
Settore BIO/09 - Fisiologia
Settore BIO/13 - Biologia Applicata
Settore MED/04 - Patologia Generale
Settore MED/13 - Endocrinologia
gen-1987
Article (author)
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/182791
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