title: Prostaglandins and the release of LHRH from hypothalamic synaptosomes. Effects of indomethacin pretreatment.
abstract: The possible role of prostaglandins (PGs) in the hypothalamic control of ovulation has been investigated by studying the effects of indomethacin (ID) and PGs on the release of luteinizing hormone-releasing hormone (LHRH) from hypothalamic synaptosomes. Female rats were chronically pretreated with ID on diestrus 2 (D2) and proestrus (P), or on diestrus 1 (D1) and D2. Basal LHRH release from hypothalamic synaptosomes prepared from rats pretreated on D2/P was reduced to 48% after a 20-min incubation period, compared with sham-treated animals. ID pretreatment on D1/D2 caused a similar but less marked reduction in LHRH release (to 66% of controls at 20 min). Extraction of the LHRH remaining within the synaptosomal pellet showed that ID pretreatment also reduced the synaptosome content of LHRH. (15S)-15-methyl PGE2 (15-E2) (10(-4) and 10(-6) M) added to the incubating medium stimulated the release of LHRH BY APPROXIMATELY 40%, but this effect was only observed in synaptosomes prepared from ID-treated rats. PGE2 (10(-4) and 10(-6) M) had no significant effect in either sham-treated or ID-treated groups.
mesh_terms: D000818:Animals; D004031:Diestrus; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D007213:Indomethacin / Q000008:administration & dosage* / Q000494:pharmacology; D011247:Pregnancy; D011359:Proestrus; D011458:Prostaglandins E / Q000008:administration & dosage* / Q000494:pharmacology; D011459:Prostaglandins E, Synthetic / Q000008:administration & dosage; D051381:Rats; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism
chemical_list: D011458:Prostaglandins E; D011459:Prostaglandins E, Synthetic; D007987:Gonadotropin-Releasing Hormone; D007213:Indomethacin