Monoaminergic and cholinergic stimulation of masculine sexual behavior in neonatally demasculinized male rats.
Sexual behavior during adulthood largely depends upon hormonal events that take place around birth. Administration of the antiestrogen Tamoxifen (Tx) to males immediately after birth induces a marked decrease of masculine sexual behavior during adulthood. On the other hand, it is well known that masculine sexual behavior can be stimulated by the administration of drugs acting specifically on the monoaminergic or the cholinergic systems. This study was performed to analyze if masculine sexual behavior can be pharmacologically stimulated in adult male rats neonatally demasculinized by the administration of Tx. Neonatal administration of Tx induced clear impairments of masculine sexual behavior during adulthood. Administration of oxotremorine (OXO), 8-OH-DPAT (8-hydroxy-2(di-n-propylaminotetraline)), yohimbine (YH), and apomorphine (APO), drugs that normally elicit a stimulation of masculine sexual behavior were unable to fully restore it in demasculinized males. Only slight improvements of some behavioral parameters were observed with 8-OH-DPAT and YH. OXO seems to induce a worsening of sexual behavior impairments. Results obtained with APO were not significantly different from saline controls. Data suggest that neonatal treatment with Tx induces permanent impairments of the neural circuitry regulating masculine sexual behavior not only limited to morphological changes but also functional alterations of the neurotransmitter systems.
Department of Reproductive Biology, Universidad Autonoma Metropolitana-Iztapalapa, Mexico City, CP 09340, Mexico.
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A
Morales-Otal
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A
Ferreira-Nuno
J
J
Velazquez-Moctezuma
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D015306:Biogenic Monoamines / Q000494:pharmacology* / Q000502:physiology; D018678:Cholinergic Agents / Q000494:pharmacology*; D004965:Estrogen Antagonists / Q000494:pharmacology; D005260:Female; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D012726:Sexual Behavior, Animal / Q000187:drug effects* / Q000502:physiology*; D013629:Tamoxifen / Q000494:pharmacology
D000317:Adrenergic alpha-Antagonists; D015306:Biogenic Monoamines; D018678:Cholinergic Agents; D004965:Estrogen Antagonists; D017366:Serotonin Receptor Agonists; D013629:Tamoxifen