title: Involvement of prolactin in the meloxicam-dependent inflammatory response of the gonadotropic axis to prolonged lipopolysaccharide treatment in anoestrous ewes.
abstract: An immune challenge can affect the reproductive process in females. Peripheral administration of bacterial endotoxin (lipopolysaccharide; LPS) decreases LH secretion and disrupts ovarian cyclicity. The aim of the present study was to determine the effects of a cyclo-oxygenase (COX)-2 inhibitor (meloxicam) on gonadotropin-releasing hormone (GnRH) and LH secretion in anoestrous ewes during systemic inflammation induced by LPS. LPS (400ngkg-1per day) suppressed LH release. In three individuals, meloxicam (500μgkg-1, i.v.) abolished LPS-induced LH suppression. In another three ewes LH was ineffective. Similar changes were observed in hypothalamic GnRH expression. The effect of meloxicam depended on the circulating level of prolactin: meloxicam abolished inflammatory-dependent suppression of GnRH and LH secretion when plasma prolactin levels were similar to those in untreated animals, but was ineffective in those with elevated levels of prolactin. We conclude that COX-2 inhibitors minimise the negative effect of inflammation on the reproductive system but that this effect may be antagonised by prolactin.
authors.affiliation: Polish Academy of Sciences, The Kielanowski Institute of Animal Physiology and Nutrition, 05-110 Jab?onna, Poland.
authors.forename: Andrzej P
authors.initials: AP
authors.lastname: Herman
authors.affiliation: Polish Academy of Sciences, The Kielanowski Institute of Animal Physiology and Nutrition, 05-110 Jab?onna, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Krawczyńska
authors.affiliation: Polish Academy of Sciences, The Kielanowski Institute of Animal Physiology and Nutrition, 05-110 Jab?onna, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Bochenek
authors.affiliation: Polish Academy of Sciences, The Kielanowski Institute of Animal Physiology and Nutrition, 05-110 Jab?onna, Poland.
authors.forename: Hanna
authors.initials: H
authors.lastname: Antushevich
authors.affiliation: The Academy of Cosmetics and Health Care, 13 Podwale Street, 00-252 Warsaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Herman
authors.affiliation: Polish Academy of Sciences, The Kielanowski Institute of Animal Physiology and Nutrition, 05-110 Jab?onna, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Tomaszewska-Zaremba
mesh_terms: D000818:Animals; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D007249:Inflammation / Q000503:physiopathology*; D008070:Lipopolysaccharides; D007986:Luteinizing Hormone / Q000378:metabolism*; D000077239:Meloxicam; D011388:Prolactin / Q000502:physiology*; D012756:Sheep; D013843:Thiazines / Q000494:pharmacology*; D013844:Thiazoles / Q000494:pharmacology*
chemical_list: D016861:Cyclooxygenase Inhibitors; D008070:Lipopolysaccharides; D013843:Thiazines; D013844:Thiazoles; D007987:Gonadotropin-Releasing Hormone; D011388:Prolactin; D007986:Luteinizing Hormone; D000077239:Meloxicam