title: 15-Lipoxygenase products stimulate prolactin secretion from a cloned strain of rat pituitary cells.
abstract: Arachidonic acid and its lipoxygenase products may contribute to the process of prolactin (PRL) release. In the present study we investigate the role of 15-hydroperoxyeicosatetraenoic acid (15-HPETE) and 15-hydroxyeicosatetraenoic acid (15-HETE) on PRL secretion from GH3 cells. The incubation of GH3 cells with the lipoxygenase product 15-HETE significantly increased PRL release in a concentration-dependent manner. Nordihydroguaiaretic acid (NDGA), which reduces the production of arachidonate metabolites via the lipoxygenase pathway, also reduced basal and TRH or arachidonic-acid-stimulated-PRL release. The inhibitory effect of NDGA on PRL release could be overcome by the addition of 15-HETE. The time course curve of PRL release from cells challenged by 15-HETE had the same profile as that of cells stimulated by TRH. The stimulating effect of 15-HPETE (ED50 = 0.7 x 10(-9) M), which is the direct precursor of 15-HETE, on PRL release was greater than TRH or 15-HETE (ED50 = 6.5 x 10(-9) M). Furthermore 15-HPETE and 15-HETE seemed to affect the release of newly synthesized PRL. These data indicate that 15-HETE and 15-HPETE could be important intracellular components in the control of PRL secretion and may account for at least a part of arachidonate-induced PRL release from GH3.
mesh_terms: D000818:Animals; D001093:Arachidonate 15-Lipoxygenase / Q000378:metabolism*; D001091:Arachidonate Lipoxygenases / Q000378:metabolism*; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism / Q000494:pharmacology*; D002460:Cell Line; D006893:Hydroxyeicosatetraenoic Acids / Q000494:pharmacology*; D007213:Indomethacin / Q000494:pharmacology; D007700:Kinetics; D015289:Leukotrienes; D008054:Lipid Peroxides / Q000494:pharmacology*; D009637:Masoprocol / Q000494:pharmacology; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism*; D011388:Prolactin / Q000096:biosynthesis / Q000378:metabolism*; D051381:Rats
chemical_list: D001095:Arachidonic Acids; D006893:Hydroxyeicosatetraenoic Acids; D015289:Leukotrienes; D008054:Lipid Peroxides; D016718:Arachidonic Acid; C025086:15-hydroperoxy-5,8,11,13-eicosatetraenoic acid; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; D009637:Masoprocol; D011388:Prolactin; D001091:Arachidonate Lipoxygenases; D001093:Arachidonate 15-Lipoxygenase; D007213:Indomethacin