title: Isoflavones and their effects on the onset of puberty in male Wistar rats.
abstract: This study was performed to determine how two of the most important isoflavones, genistein and daidzein, affect the gonadal axis in male prepuberal rats. One hundred and seventy-five prepuberal male Wistar rats were allocated into seven groups: one control group and six experimental groups that were orally administered a high or low dose of genistein, daidzein or a mixture of both. Testosterone determination was assayed by EIA. The testes and body weights were measured, and the histology of the epididymis with the sperm content and epididymal sperm count were evaluated. In the control group, we observed an increase in the serum testosterone levels (>2.5 ng ml(-1) ) at the third week (52 days), which corresponded to the onset of puberty in these rats. The same increase in serum testosterone levels was observed at the fourth week in rats that received low doses of isoflavones; therefore, we concluded that the onset of puberty was delayed. At high doses, there was no significant increase in testosterone levels, which could be related to the fact that these male rats did not reach puberty. These findings were supported by the results obtained from the analysis of the epididymal content as well as the testes/body weight ratio.
authors.affiliation: Dpto. Fisiología Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Caceres
authors.affiliation: Dpto. Medicina y Cirugía Animal, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Peña
authors.affiliation: Dpto. Fisiología Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Moyano
authors.affiliation: Dpto. Fisiología Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Martinez-Fernandez
authors.affiliation: Dpto. Fisiología Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Monsalve
authors.affiliation: Dpto. Fisiología Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: M J
authors.initials: MJ
authors.lastname: Illera
authors.affiliation: Dpto. Fisiología Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Millan
authors.affiliation: Dpto. Fisiología Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: J C
authors.initials: JC
authors.lastname: Illera
authors.affiliation: Dpto. Fisiología Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Silvan
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004822:Epididymis / Q000187:drug effects; D019833:Genistein / Q000008:administration & dosage / Q000494:pharmacology*; D007529:Isoflavones / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D012741:Sexual Maturation / Q000187:drug effects*; D013737:Testis / Q000187:drug effects; D013739:Testosterone / Q000097:blood
chemical_list: D007529:Isoflavones; D013739:Testosterone; C004742:daidzein; D019833:Genistein
keywords: Daidzein; genistein; phytoestrogens; puberty; testis; testosterone