RESUMO
INTRODUCTION: Fluoxetine, like other selective serotonin reuptake inhibitors, inhibits women's sexual desire and female rats' sexual behavior. Bupropion produces pro-sexual effects in women with and without depression, and yohimbine increases men's and male rats' sexual motivation, but their effects on female rats' proceptivity are unknown. AIM: To investigate the effects of fluoxetine, bupropion, and yohimbine on proceptivity and receptivity in the naturally cycling female rat. METHODS: We studied the effect of chronic (minimum 14 days) fluoxetine (1.25 mg/kg, subcutaneous) and bupropion (5 mg/kg, intraperitoneal) and acute yohimbine (1 mg/kg, intraperitoneal) on sexual behavior of female rats selected in natural proestrus during an ejaculatory series. We also analyzed the effects of these treatments on locomotor activity. MAIN OUTCOME MEASURES: The main outcome measures were frequencies of hops/darts and ear wiggling, lordosis quotient and intensity, and locomotor activity. RESULTS: Fluoxetine inhibited ear wiggling and hopping/darting, while bupropion stimulated hopping/darting. These treatments did not modify the lordosis quotient and its intensity. Yohimbine did not change any aspect of female sexual behavior. At the doses and treatments used, fluoxetine and bupropion did not alter locomotor activity or disturb the length of the estrous cycle; however, yohimbine inhibited locomotor activity. CONCLUSIONS: The motivational components of female sexual behavior are more sensitive than the receptive components to the inhibitory actions of fluoxetine. Bupropion selectively stimulated hopping/darting, while yohimbine lacked an action on female sexual behavior.
Assuntos
Antidepressivos/farmacologia , Bupropiona/farmacologia , Fluoxetina/farmacologia , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Comportamento Sexual Animal/efeitos dos fármacos , Animais , Ciclo Estral/efeitos dos fármacos , Feminino , Humanos , Masculino , Ratos , Fatores Sexuais , Ioimbina/farmacologiaRESUMO
The mating inhibition after repeated copulation (sexual satiety) and its re-commencement after changing the sexually active partner (Coolidge effect) are well recognized phenomena in males, but their occurrence in females is little explored. These two phenomena were compared in conditions when the female regulates copulation timing (pacing) and under non-paced mating. Female rats selected in proestrus copulated incessantly for 3 h with two different partners (for 90 min each), both of them sexually active and unknown for the female. During the entire test we recorded the hop/dart and ear wiggling frequencies and the lordosis quotient. In the pacing test we also registered the percentage of exits and the return latencies after mounts, intromissions and ejaculation within each copulatory series, the mean time the female spent in the neutral chamber and the number of crossings. In the non-paced mating situation there was a reduction in ear wiggling and hop/darting frequencies after 3 h of constant copulation. In the paced mating condition, also by the end of the test, the female spent more time in the neutral compartment and showed fewer crossings to the male's zone. Only when the female regulated mating, the change of the male provoked an increased hop/darting frequency accompanied by a reduced percentage of exits from the male's chamber after an intromission and in the time in the neutral compartment. These changes were not associated with alterations in receptivity, which was maximal along the test. Data are discussed by comparing the mating conditions and the sex differences in the effect of repeated copulation and partner replacement.