Publications (2)3.76 Total impact
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Article: Nitric oxide stimulates progesterone and prostaglandin E2 secretion as well as angiogenic activity in the equine corpus luteum.
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ABSTRACT: Cytokines and nitric oxide (NO) are potential mediators of luteal development and maintenance, angiogenesis, and blood flow. The aim of this study was to evaluate (i) the localization and protein expression of endothelial and inducible nitric oxide synthases (eNOS and iNOS) in equine corpora lutea (CL) throughout the luteal phase and (ii) the effect of a nitric oxide donor (spermine NONOate, NONOate) on the production of progesterone (P4) and prostaglandin (PG) E(2) and factor(s) that stimulate endothelial cell proliferation using equine luteal explants. Luteal tissue was classified as corpora hemorrhagica (CH; n = 5), midluteal phase CL (mid-CL; n = 5) or late luteal phase CL (late CL; n = 5). Both eNOS and iNOS were localized in large luteal cells and endothelial cells throughout the luteal phase. The expression of eNOS was the lowest in mid-CL (P < 0.05) and the highest in late CL (P < 0.05). However, no change was found for iNOS expression. Luteal explants were cultured with no hormone added or with NONOate (10(-5) M), tumor necrosis factor-α (TNFα; 10 ng/mL; positive control), or equine LH (100 ng/mL; positive control). Conditioned media by luteal tissues were assayed for P4 and PGE(2) and for their ability to stimulate proliferation of bovine aortic endothelial cells (BAEC). All treatments stimulated release of P4 in CH, but not in mid-CL. TNFα and NONOate treatments also increased PGE(2) levels and BAEC proliferation in CH (P < 0.05). However, in mid-CL, no changes were observed, regardless of the treatments used. These data suggest that NO and TNFα stimulate equine CH secretory functions and the production of angiogenic factor(s). Furthermore, in mares, NO may play a role in CL growth during early luteal development, when vascular development is more intense.Domestic animal endocrinology 09/2010; 40(1):1-9. · 1.65 Impact Factor -
Article: Actions of a nitric oxide donor on prostaglandin production and angiogenic activity in the equine endometrium.
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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.Reproduction Fertility and Development 02/2008; 20(6):674-83. · 2.11 Impact Factor
