Role of monoamines in the male differentiation of the brain induced by androgen aromatization.
Cerebral androgen aromatization has been described as a mechanism responsible for masculinization of the brain, and monoamines seem to be involved in sexual differentiation of the brain. The aim of this study was to investigate the possible implication of monoamines in the masculinization of the brain induced by cerebral androgen aromatization not only in the classic hypothalamic areas but also in some extrahypothalamic ones. For this purpose, 1-day-old male Wistar rats were injected intraventricularly with 5 mg/kg of a suspension of an aromatase inhibitor, LY43578. Saline was administered to male and female control groups. At adulthood, open-field, heterotypical, and homotypical sexual behavior tests were performed and cerebral amines were determined by HPLC-ED. Behavioral tests revealed feminine-like exploratory activity and defecation rate in the treated group, as well as an 89% lordotic response and decreased number of mounts plus intromissions. Testosterone levels were not affected by the treatment. Striatal and limbic serotonergic metabolism showed a sexual dimorphism, higher in males than females, that disappeared in the treated group. From these results, we suggest a possible role of extrahypothalamic serotonin in the mediation of the estrogen-induced mechanisms of behavioral sexual differentiation.
González
M I
MI
Departamento de Biologia Animal II (Fisiologia Animal), Facultad de Ciencias Biológicas Universidad Complutense, Madrid, Spain.
Leret
M L
ML
D000728:Androgens / Q000378:metabolism*; D000818:Animals; D015306:Biogenic Monoamines / Q000494:pharmacology / Q000502:physiology*; D001921:Brain / Q000378:metabolism* / Q000502:physiology; D005260:Female; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012733:Sex Differentiation / Q000187:drug effects / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000187:drug effects
D000728:Androgens; D015306:Biogenic Monoamines