Évaluation du contenu surrénalien en androstènedione et effets de la castration chez le lapin domestique (Oryctolagus cuniculus)

DHEA, DHEA sulphate and androstenedione are C19 steroïds secreted by the adrenal cortex. These hormones with a weak androgen activity are precursors of estrogens and androgens. In human and other primates these hormones are produced in important quantities, even though, in domestic and laboratory animals, a few secretion is measured. In this survey, the androstenedione is quantified both in plasma and adrenal gland of young, prepubertal and adult rabbits and the castration effects on adrenal cortex histology are noted too. The absolute weight (AW) of the left adrenal gland is slightly higher than the right (p > 0.05) for all animals and the gland absolute weight (AW) for the adult rabbit is superior to the young and prepubertal rabitts (p < 0.05). The castration effect in adult increases the adrenal weight (p < 0.001). A zonation of adrenal cortex for young rabbits is observed. The zona fasciculata is important for young and prepubertal rabbits whereas, the zona reticularis is thicker for the adults. Thickness of glomerulosa, fasciculata and reticularis zonas increased with 6.55% (p > 0.05), 15.9% (p < 0.01) and 79.21% (p < 0.001) for the castred adult rabbits and histological modifications were observed in the zona reticularis. The plasma androstenedione is negligible for the young (0.060 ± 0.01 ng/mL), weak for the prepubertal (0.152 ± 0.03 ng/mL) and reaches (0.263 ± 0.03 ng/mL) for the adult. The androstenedione relative content (ng/100 mg of adrenal weight) is 2.90 ± 0.30; 4.54 ± 0.82 and 1.34 ± 0.36 for the young, prepubertal and adult rabbits. In this work, an increase of the androstenedione adrenal content is observed for the prepubertal rabbits, which could intervene in the process of puberty.