The effect of boar seminal plasma on the release of prostaglandins and interleukin-6 by porcine endometrial and cervical cells and bovine endometrial cells.

Artificial insemination (AI) of sows results in a significant elevation of prostaglandin F(2α) metabolite (PGFM) levels in peripheral plasma, whereas in mated sows such elevation is not seen. The aim of this study was to investigate whether boar seminal plasma (SP) has any effect on the release of PGFM, prostaglandin F(2α) (PGF(2α) ), prostaglandin E(2) (PGE(2) ) or interleukin-6 (IL-6) by in vitro cultured porcine endometrial (epithelial - pUE and stromal - pUS), cervical (pCE and pCS) and bovine endometrial epithelial cells (bUE). This study shows that boar SP inhibits the release of PGFM, PGF(2α) and PGE(2) by porcine endometrial and cervical cells and bovine endometrial cells after 3 and 24 h incubation. Boar SP stimulated IL-6 release by pUE, pUS and even bUE after 3 h incubation. Tumour necrosis factor α (TNFα) stimulated the release of IL-6 by pUS only after 24 h incubation, but in the presence of boar SP, this stimulation was attenuated. The overall results from these in vitro studies give us possibility to understand the difference in prostaglandin response between mated and inseminated sows. Furthermore, we demonstrated that frozen-stored epithelial and stromal cells from pig endometrium, as well as from the cervix are suitable for studying the effect of SP on the release of prostaglandins. The only prerequisite is to incubate these thawed cells with arachidonic acid as a source for the synthesis of prostaglandins. A similar effect of boar SP on porcine and bUE cells may suggest inter-species reactivity.

Restricted feed intake in lactating primiparous sows. II. Effects on subsequent litter sex ratio and embryonic gene expression.

Expression of panels of candidate genes controlling myogenesis, angiogenesis and gender-specific imprinting of development were analysed in embryonic, placental and endometrial tissues recovered at Day 30 of gestation from a subset of primiparous sows that were either feed restricted (Restrict; n=17) or fed to appetite (Control; n=15) during the last week of the previous lactation. Embryos were also sex typed to investigate gender bias in response to treatments. Average embryonic weight was lower in the subset of Restrict compared with Control litters (1.38±0.07vs 1.59±0.08g, respectively) and the male:female sex ratio was higher (P<0.05) in embryos (litters) recovered from Restrict sows. Treatment affected (P≤0.05) the expression of embryonic and placental genes involved in insulin-like growth factor (IGF) 2 signalling, including IGF2, INSR and IGF2R. Embryonic expression of ESR1 was also affected by treatment (P<0.03) and sex×treatment interactions were observed for the expression of embryonic ESR1 (P<0.05) and placental ANGPT2 (P<0.03). At the molecular level, these results support the suggestion that changes in placental function are not the primary mechanism mediating detrimental effects of previous sow catabolism on early embryonic development in the feed-restricted lactational sow model. However, perturbations in the IGF2 system are implicated as mediators of these effects.

Genistein alters the release of oxytocin, prostaglandins, cortisol and LH during insemination in gilts.

Soya products containing phytooestrogens are widely used as feed for pigs. However, limited data are available on the effects of phytooestrogen on the endocrine status of pigs. The aim of this work was to study the impact of the phytooestrogen genistein added to a soya-free diet on the hormonal pattern in gilts during oestrus and artificial insemination (AI). Ten gilts were fed a soya-free diet and fitted with jugular vein catheter through vena auricularis. The gilts were randomly divided into two groups (G- and C-group) where the G-group was given pure genistein, 1 mg/kg body weight (BW) twice daily, per os. Blood samples were collected before, during and after AI. Oxytocin, prostaglandin E2, prostaglandin F2(α), 13,14-dihydro-15-keto-prostaglandin F2(α) (PGFM), cortisol and LH concentrations in blood plasma were analysed. Oxytocin concentrations were almost twice as high in the G-group as in C-group after the AI. Prostaglandin E2 concentrations were higher in G-group than in C-group during the entire sampling period. After AI, the concentrations of prostaglandin E2 increased in G-group but not in C-group. Prostaglandin F2(α) concentration had a pulsatile pattern, with increasing pulses after AI in G-group. Plasma PGFM concentrations increased after AI with a small variation between the groups. Plasma cortisol concentration increased after AI in C-group. LH decreased after AI in G-group. Genistein stimulated elevations of plasma oxytocin and prostaglandin E2 concentrations and a pulsative pattern in prostaglandin F2(α) concentration. The possible involvement of genistein in plasma cortisol and basal LH concentrations in gilts given genistein may also be suggested.