title: Serotonergic influences on pituitary gland and hypothalamic induction of prolactin and luteinizing hormone release in the young turkey (Meleagris gallopavo).
abstract: Primary anterior pituitary cell cultures were utilized to study the influence of serotonin (5-HT) directly on the pituitary. Cells incubated with 10(-5) and 10(-4) M 5-HT exhibited a significant prolactin (Prl) release, whereas cells incubated with 10(-10) to 10(-6) M 5-HT did not. Cells incubated with 10(-10) to 10(-4) M quipazine (5-HT agonist) or methysergide (MES; 5-HT antagonist) did not release Prl in amounts greater/less (P greater than 0.01) than spontaneous release. Luteinizing hormone (LH) release from cells incubated in the presence of 5-HT, quipazine, or MES was similar to spontaneous release. The hypothalamic extract-induced Prl and LH release from cells was not influenced by quipazine, but Prl release was diminished in a dose-related fashion by MES. The influence of 5-HT on hypothalamic induction of Prl and LH release was investigated utilizing in vitro culture of hypothalamic fragments (HF). Media samples from HF incubated with 10(-6) and 10(-4) M 5-HT induced a release of Prl. Media samples from HF incubated with 10(-4) M MES induced less Prl release than media samples from control fragments. When HF were incubated with both 10(-4) M 5-HT and 10(-4) M MES, the expected 5-HT-mediated Prl release was not evident. These culturing situations had no influence on LH release. In vitro Prl release from pituitary cells of the young turkey was stimulated through 5-HT activity at the hypothalamus, but not by direct 5-HT action on the pituitary cells.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology*; D007986:Luteinizing Hormone / Q000378:metabolism*; D008784:Methysergide / Q000494:pharmacology; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism; D011388:Prolactin / Q000378:metabolism*; D011814:Quipazine / Q000494:pharmacology; D012636:Secretory Rate / Q000187:drug effects; D012701:Serotonin / Q000502:physiology*; D014422:Turkeys / Q000502:physiology*
chemical_list: D012701:Serotonin; D011814:Quipazine; D011388:Prolactin; D007986:Luteinizing Hormone; D008784:Methysergide