title: Luteinizing hormone induces ovulation via tumor necrosis factor α-dependent increases in prostaglandin F2α in a nonmammalian vertebrate.
abstract: Ovulation is induced by the preovulatory surge of luteinizing hormone (LH) that acts on the ovary and triggers the rupture of the preovulatory ovarian follicle by stimulating proteolysis and apoptosis in the follicle wall, causing the release of the mature oocyte. The pro-inflammatory cytokine tumor necrosis factor α (TNFα) and prostaglandin (PG) F2α (PGF2α) are involved in the control of ovulation but their role mediating the pro-ovulatory actions of LH is not well established. Here we show that Lh induces PGF2α synthesis through its stimulation of Tnfα production in trout, a primitive teleost fish. Recombinant trout Tnfα (rTnfα) and PGF2α recapitulate the stimulatory in vitro effects of salmon Lh (sLh) on contraction, proteolysis and loss of cell viability in the preovulatory follicle wall and, finally, ovulation. Furthermore, all pro-ovulatory actions of sLh are blocked by inhibition of Tnfα secretion or PG synthesis and all actions of rTnfα are blocked by PG synthesis inhibitors. Therefore, we provide evidence that the Tnfα-dependent increase in PGF2α production is necessary for the pro-ovulatory actions of Lh. The results from this study shed light onto the mechanisms underlying the pro-ovulatory actions of LH in vertebrates and may prove important in clinical assessments of female infertility.
authors.affiliation: Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Avinguda Diagonal 643, 08028 Barcelona, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Crespo
authors.affiliation: School of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 E. Greenfield Avenue, WI 53204, USA.
authors.forename: Frederick W
authors.initials: FW
authors.lastname: Goetz
authors.affiliation: Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Avinguda Diagonal 643, 08028 Barcelona, Spain.
authors.forename: Josep V
authors.initials: JV
authors.lastname: Planas
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D015237:Dinoprost / Q000378:metabolism*; D005260:Female; D007986:Luteinizing Hormone / Q000378:metabolism* / Q000494:pharmacology; D006080:Ovarian Follicle / Q000187:drug effects / Q000502:physiology; D010053:Ovary / Q000187:drug effects / Q000502:physiology*; D010060:Ovulation / Q000187:drug effects; D059748:Proteolysis / Q000187:drug effects; D014337:Trout; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism* / Q000494:pharmacology; D014714:Vertebrates
chemical_list: D014409:Tumor Necrosis Factor-alpha; D007986:Luteinizing Hormone; D015237:Dinoprost