Resumo

SALAME-MENDEZ, Arturo et al. Evaluación estacional de la producción de esteroides sexuales en testículos del ratón de orejas oscuras (Peromyscus melanotis, Allen & Chapman, 1897) de diferentes clases de edad. Acta Zool. Mex [online]. 2004, vol.20, n.2, pp.103-114. ISSN 2448-8445.

Ontological and seasonal production of sexual steroids (SS) were evaluated in testicles of dark-eared mice (Peromyscus melanotis), assigned to five age groups, according to wear of molar crowns. Testicular production of testosterone and Δ4 intermediates (progesterone and androstendione) increases with the onset of adulthood and decreases with senescence, though it does not stops completely. From an endocrine point of view, the five age categories become three age stages: juveniles (juveniles and subadults), adults (young and mature), and old individuals. Analysis of seasonal production of SS in this species, suggests a one-modal pattern with its peak in Summer. These are the first evidences on production of SS documented from free-living individuals of both the genus Peromyscus and P. melanotis.

Palavras-chave : Rodents; Peromyscus melanotis; testes; sexual steroids; wild mice; Mexico.

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