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.

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.