Serotonin inhibits luteinizing hormone release via 5-HT1A receptors in the zona incerta of ovariectomised, anaesthetised rats primed with steroids.

TitleSerotonin inhibits luteinizing hormone release via 5-HT1A receptors in the zona incerta of ovariectomised, anaesthetised rats primed with steroids.
Publication TypeJournal Article
Year of Publication2000
AuthorsSiddiqui, A, Kotecha, K, Salicioni, AM, Kalia, V, Murray, JF, Wilson, CA
JournalNeuroendocrinology
Volume72
Issue5
Pagination272-83
Date Published2000 Nov
Keywords8-Hydroxy-2-(di-n-propylamino)tetralin, Anesthesia, Animals, Estradiol, Female, Luteinizing Hormone, Ovariectomy, Piperazines, Progesterone, Rats, Rats, Wistar, Receptors, Serotonin, Receptors, Serotonin, 5-HT1, Ritanserin, Serotonin, Serotonin Antagonists, Serotonin Receptor Agonists, Subthalamus
AbstractThe zona incerta (ZI), an area in the dorsal hypothalamus, contains neuronal systems that appear to control gonadotropin release. Previous findings show that there is an inverse relationship between serotonin (5-HT) activity in the ZI and plasma luteinizing hormone (LH) levels, indicating that the 5-HT system in this area has an inhibitory effect on LH release. Employing anaesthetised, ovariectomised rats primed with 5 microg oestradiol benzoate followed at 48 h by 0.5 mg progesterone, we have shown that 2 microg/side 5-HT in the ZI inhibits the LH surge that normally occurs 4 h after the progesterone treatment. This effect was mimicked by 2 microg/side 8-OH-DPAT, a 5-HT1A agonist, but not by DOI, a 5-HT2 agonist, BMY7378, a presynaptic 5-HT1A agonist or MCPP, a 2B & 2C agonist. The inhibitory effect of 5-HT and 8-OH-DPAT was prevented by pretreatment, 1 h before, with either 2 mg/kg i.p. WAY100135, a 5-HT1A antagonist or 0.25 mg/kg i.p. ritanserin, a 5-HT2 antagonist. These results indicate that 5-HT in the ZI exerts its inhibitory effect on LH release via 5-HT1A receptors but that another 5-HT subtype may also be involved.
Alternate JournalNeuroendocrinology