LH discharge induced by medial preoptic implantation of estrone or dopamine in the ovariectomized estradiol primed rat.
Effect of implantation of estrogens or catecholamines into the medial preoptic area through chronically implanted double cannula on the release of LH was examined in the ovariectomized estradiol-primed rat. Implantation of estrone at 12:00 on the second or third day after subcutaneous injection of estradiol benzoate (20 mug) increased the serum concentration of LH at 18:00 compared with that in the non-implanted controls, whereas implantation of estradiol benzoate on the third day did not affect it. Dopamine implantation at 12:00 on the third day also induced a significant increase of LH concentration at 18:00, and, in contrast, norepinephrine implantation decreased the concentration at 18:00. It may be said that the medial preoptic area is responsive to estrone and can induce LH release, whereas it is not to estradiol. Furthermore, dopamine was effective for the activation of the medial preoptic area in relation to the inducement of LH release.
D000818:Animals; D002369:Castration; D004298:Dopamine / Q000008:administration & dosage / Q000494:pharmacology*; D004958:Estradiol / Q000494:pharmacology*; D004970:Estrone / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D007031:Hypothalamus / Q000187:drug effects*; D007986:Luteinizing Hormone / Q000097:blood*; D009638:Norepinephrine / Q000008:administration & dosage / Q000494:pharmacology; D011301:Preoptic Area / Q000187:drug effects*; D051381:Rats
D004970:Estrone; D004958:Estradiol; D007986:Luteinizing Hormone; D004298:Dopamine; D009638:Norepinephrine