Ações da epitestosterona através de um mecanismo de membrana em células de Sertoli : implicações no desenvolvimento sexual

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

2012

RESUMO

Introduction: Epitestosterone is the 17¿-epimer of testosterone. It seems to possess an antiandrogenic activity, as well as a neuroprotective effect. The mechanism of action of epitestosterone has not been elucidated. Objective: The aim of this work is to investigate the non-classical effect of epitestosterone on the membrane of Sertoli cells from testis of 12-, 15-, 21- and 35-day-old rats. Materials and Methods: The membrane potential and the membrane input resistance of Sertoli cells was recorded using a standard single microelectrode technique. Application of epitestosterone (0.5, 1 and 2¿M) or testosterone (1¿M) alone and after infusion with flutamide (1¿M), verapamil (100¿M) or U73122 (2¿M) was made. The testes from 12-day-old rats were pre-incubated with 45Ca2+ with or without flutamide (1¿M) and incubated with epitestosterone (1¿M) or testosterone (1¿M). Student s t-test or ANOVA for repeated measures with Bonferroni post-test was used. Results: Epitestosterone produced a depolarization in the membrane potential and increased the input membrane resistance on Sertoli cells from 15-, 21- and 35-day-old rats. This steroid showed a similar response to testosterone. The effect of epitestosterone was not changed after perfusion with flutamide, an intracellular androgen receptor inhibitor. Epitestosterone increased 45Ca2+ uptake within 5 minutes and this effect was also not inhibited by flutamide. The depolarizing effect was slightly inhibited by verapamil, a voltage-dependent calcium channel blocker, and by U73122, a PLC inhibitor. Conclusion: These results indicate that epitestosterone acts on the Sertoli cells via a non-classical signaling pathway; the effects are similar to that of testosterone in Sertoli cells in whole seminiferous tubules from rat testes.

ASSUNTO(S)

epitestosterona células de sertoli desenvolvimento sexual

ACESSO AO ARTIGO

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