title: Actions of a nitric oxide donor on prostaglandin production and angiogenic activity in the equine endometrium.
abstract: Nitric oxide (NO) plays an important role in prostaglandin secretion and angiogenesis in the reproductive system. In the present study, the roles of the NO donor spermine NONOate and tumour necrosis factor-alpha (TNF; as a positive control) in prostaglandin production and angiogenic activity of equine endometria during the oestrous cycle were evaluated. In addition, the correlation between NO production and the expression of key prostaglandin synthase proteins was determined. The protein expression of prostaglandin F synthase (PGFS) increased in early and mid-luteal stages, whereas that of prostaglandin E synthase (PGES) was increased in the early luteal stage. The in vitro release of NO was highest after ovulation. There was a high correlation between NO production and PGES expression, as well as NO release and PGFS expression. There were no differences detected in prostaglandin H synthase 2 (PTGS-2) throughout the oestrous cycle and there was no correlation between PTGS-2 expression and NO. In TNF- or spermine-treated endometria, the expression of prostaglandin (PG) E(2) increased in the early and mid-luteal phases, whereas that of PGF(2alpha) increased in the follicular and late luteal phases. Bovine aortic endothelial cell (BAEC) proliferation was stimulated in TNF-treated follicular-phase endometria. However, in spermine-treated endometria, NO delivered from its donor had no effect, or even an inhibitory effect, on BAEC proliferation. In conclusion, despite no change in PTGS-2 expression throughout the oestrous cycle in equine endometrial tissue, there were changes observed in the expression of PGES and PGFS, as well as in the production of PGE(2) and PGF(2alpha). In the mare, NO is involved in the secretory function of the endometrium, modulating PGE(2) and PGF(2alpha) production. Even though TNF caused an increase in the production of angiogenic factors and prostaglandins, its complex action in mare uterus should be elucidated.
authors.affiliation: Department of Animal Sciences, Escola Superior Agrria de Coimbra, Bencanta, Coimbra, Portugal.
authors.forename: Rosário P
authors.initials: RP
authors.lastname: Roberto da Costa
authors.forename: Ana S
authors.initials: AS
authors.lastname: Costa
authors.forename: Anna J
authors.initials: AJ
authors.lastname: Korzekwa
authors.forename: Rafal
authors.initials: R
authors.lastname: Platek
authors.forename: Marta
authors.initials: M
authors.lastname: Siemieniuch
authors.forename: António
authors.initials: A
authors.lastname: Galvão
authors.forename: Dale A
authors.initials: DA
authors.lastname: Redmer
authors.forename: José Robalo
authors.initials: JR
authors.lastname: Silva
authors.forename: Dariusz J
authors.initials: DJ
authors.lastname: Skarzynski
authors.forename: Graça
authors.initials: G
authors.lastname: Ferreira-Dias
mesh_terms: D000818:Animals; D002417:Cattle; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004717:Endometrium / Q000187:drug effects* / Q000378:metabolism*; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D030762:Estrous Cycle / Q000187:drug effects; D005260:Female; D006736:Horses / Q000378:metabolism*; D018919:Neovascularization, Physiologic / Q000187:drug effects* / Q000502:physiology; D009569:Nitric Oxide / Q000494:pharmacology; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011453:Prostaglandins / Q000096:biosynthesis* / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D020030:Nitric Oxide Donors; D011453:Prostaglandins; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D011451:Prostaglandin-Endoperoxide Synthases