Median eminence serotonin involved in the proestrus gonadotropin release
| Autor: | de las Nieves Parisi M, Chiocchio, Vitale Ml, Tramezzani Jh |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
endocrine system
medicine.medical_specialty Serotonin medicine.drug_class Endocrinology Diabetes and Metabolism Biology Cellular and Molecular Neuroscience Endocrinology Anterior pituitary Estrus Pituitary Gland Anterior Pregnancy Lactation Internal medicine medicine Animals Morning Estrous cycle Endocrine and Autonomic Systems Median Eminence Luteinizing Hormone Prolactin Rats medicine.anatomical_structure Median eminence Gonadotropins Pituitary Female Proestrus Gonadotropin Follicle Stimulating Hormone hormones hormone substitutes and hormone antagonists Hormone |
| Zdroj: | Neuroendocrinology. 39(2) |
| ISSN: | 0028-3835 |
| Popis: | Numerous studies have suggested that serotonin (5-HT) is involved in the regulation of anterior pituitary hormone release. In the present study, the 5-HT concentrations of the median eminence and anterior pituitary lobe were measured during the estrous cycle and lactation in order to correlate changes in 5-HT levels with changes in serum luteinizing hormone, follicle-stimulating hormone, and prolactin. On the day of proestrus, median eminence 5-HT concentrations declined significantly between 14.00 and 16.30 h at the beginning of the gonadotropin and prolactin surges. No changes in 5-HT concentrations were found between the morning and afternoon on other days of the cycle. In the anterior pituitary, the levels of 5-HT did not change during the estrous cycle. 5-HT turnover rates were also estimated in the median eminence on proestrus and diestrus 1. The median eminence 5-HT synthesis rate increased in the afternoon of proestrus at 16.30 h. 5-HT was also measured in the anterior pituitary and the median eminence of lactating rats in four experimental situations: mothers with their litter until decapitation, mothers separated from their pups 4 h earlier, and mothers separated from their pups 4 h earlier, after which the pups were allowed to suckle for 5 or 30 min. In spite of the acute changes in circulating prolactin, 5-HT levels in the median eminence were not affected in any situation studied. These results suggest that 5-HT in the median eminence is involved in the control of gonadotropin release. The data further suggest that 5-HT does not act directly on the anterior pituitary to modulate gonadotropin or prolactin release. |
| Databáze: | OpenAIRE |
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