In vivo and in vitro studies on the effect of the serotoninergic system on luteinizing hormone and luteinizing hormone-releasing hormone secretion in prepubertal and peripubertal female rats.
Brain Res
; 523(1): 57-61, 1990 Jul 16.
Article
em En
| MEDLINE
| ID: mdl-2207690
The present investigations were designed to assess the effect of the serotoninergic system on luteinizing hormone (LH) and LH-releasing hormone (LH-RH) secretion in female rats aged 14 and 30 days. The administration of 5-hydroxytryptophan (5-HTP; 75 mg/kg i.p.) increased hypothalamic serotonin (5-HT) concentrations in both age groups, and did not affect hypothalamic norepinephrine (NE) concentrations or release. Serum LH levels were raised by 5-HTP in 14-day-old, but not in 30-day-old rats. Basal and KCl- (28 mM) stimulated LH-RH release by incubated hypothalamic fragments was significantly enhanced when 5-HTP was injected previously to 14-day-old animals. In 30-day-old rats, 5-HTP treatment did not modify basal LH-RH release, and decreased the KCl-stimulated LH-RH output. Similarly, the addition of 5-HT (10(-7) M) to superfused hypothalamic fragments enhanced basal LH-RH release in 14-day-old rats and blocked the increment in LH-RH release evoked by KCl in 30-day-old rats. The present results show that in 14-day-old female rats, the serotoninergic system (activated in vivo by 5-HTP treatment, or in vitro by 5-HT addition) exerts a stimulatory effect on LH-RH, and thus, on LH release. On the contrary, in 30-day-old animals, stimulated LH-RH secretion was inhibited by 5-HT. Apparently, the hypothalamic NE system is not implicated in this response. The participation of this changing effect of 5-HT on LH-RH/LH release at the onset of puberty is postulated.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Hormônio Luteinizante
/
Serotonina
/
Hormônio Liberador de Gonadotropina
Limite:
Animals
Idioma:
En
Revista:
Brain Res
Ano de publicação:
1990
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Holanda