title: Effects of castration and androgen treatment on aromatase activity in the brain of mature male Atlantic salmon (Salmo salar L.) parr.
abstract: Brain homogenates from male Atlantic salmon parr aromatized tritiated androstenedione to estrogens. The aromatase activity in homogenates of whole brains from castrated male parr was lower than that in homogenates from sham-operated male parr in autumn. This was also found in homogenates of the telencephalon and diencephalon, but not in homogenates of the tectum opticum. Treatment of castrated males with testosterone (T) and 11-ketoandrostenedione (OA) increased the aromatase activity in whole brains. T, but not OA, also significantly increased aromatase activity in all brain parts. In spring, half a year after the peak breeding period, mature parr males had a lower aromatase activity in telencephalon, diencephalon and tectum than that found in castrated males in autumn, whereas immature males displayed an even lower level of activity.
authors.affiliation: Department of Zoology, University of Stockholm, Sweden.
authors.forename: I
authors.initials: I
authors.lastname: Mayer
authors.forename: B
authors.initials: B
authors.lastname: Borg
authors.forename: I
authors.initials: I
authors.lastname: Berglund
authors.forename: J G
authors.initials: JG
authors.lastname: Lambert
mesh_terms: D000728:Androgens / Q000494:pharmacology*; D000736:Androstenes / Q000494:pharmacology; D000818:Animals; D001141:Aromatase / Q000378:metabolism*; D001921:Brain / Q000187:drug effects / Q000201:enzymology*; D004027:Diencephalon / Q000187:drug effects / Q000201:enzymology; D008297:Male; D009919:Orchiectomy; D012474:Salmon / Q000378:metabolism*; D012621:Seasons; D013477:Superior Colliculi / Q000187:drug effects / Q000201:enzymology; D013687:Telencephalon / Q000187:drug effects / Q000201:enzymology; D013739:Testosterone / Q000494:pharmacology
chemical_list: D000728:Androgens; D000736:Androstenes; D013739:Testosterone; C011657:adrenosterone; D001141:Aromatase