The effects of intrauterine infusion of peanut oil on endometrial health, salivary cortisol and interovulatory period in mares

Intrauterine infusion of peanut oil at Day 10 post-ovulation has been reported to prolong dioestrus in mares. However, the effects of peanut oil treatment on the endometrium and whether the technique is painful have not been assessed. The objectives of this study were, (i) to determine the effect of intrauterine infusion of peanut oil on endometrial health, (ii) to determine whether use of intrauterine peanut oil is painful and (iii) to confirm that peanut oil causes prolonged dioestrus. Six mares aged 3–12 years old were used in a cross-over design with each mare administered both 1 ml of intrauterine peanut oil and a sham treatment on different oestrous cycles. The effect of intrauterine infusion of 1 ml peanut oil or sham treatment were measured using interovulatory period, uterine fluid accumulation as determined by transrectal ultrasonography, serum progesterone levels, endometrial Kenney biopsy scores and histological features, endometrial eosinophil numbers and salivary cortisol measurements. The individual mare response to intrauterine infusion of peanut oil was variable. Peanut oil infusion did not statistically prolong the luteal phase, nor elevate salivary cortisol levels but did cause superficial erosion of the endometrial surface epithelium in all mares and significantly increased eosinophil numbers in the endometrium (P = 0.0068). The Kenney grade for biopsies from 2/6 mares worsened transiently following infusion. In conclusion, intra-uterine peanut oil does not statistically increase the duration of the luteal phase but results in an inflammatory response and increase in endometrial eosinophil numbers suggesting treatment may be associated with a hypersensitivity-type reaction. Those contemplating using peanut oil to suppress oestrus should also be aware of the legislative and regulatory implications

Ácido cianídrico em tecidos de mandioca em função da idade da planta e adubação nitrogenada

O objetivo deste trabalho foi avaliar o teor de ácido cianídrico em tecidos de mandioca, em função da idade da planta e níveis de adubação nitrogenada. Utilizou-se o delineamento experimental de blocos ao acaso, em arranjo de parcelas subdivididas, com quatro repetições. As doses de nitrogênio em cobertura (0, 30, 60, 150 e 330 kg ha-1) foram alocadas nas parcelas, e as épocas de avaliação (90, 120, 150, 180, 240, 300 e 360 dias após o plantio), nas subparcelas. Os teores de ácido cianídrico foram avaliados em tecidos da folha, caule, polpa e córtex da raiz da cultivar Aciolina. Os efeitos das doses de N e das épocas de avaliação foram independentes. Doses entre 219 e 241 kg ha-1 de N em cobertura proporcionam os maiores teores de ácido cianídrico, que variaram de 332 a 401 mg kg-1 de matéria fresca nos tecidos avaliados. O teor de ácido cianídrico nos tecidos reduz-se linearmente com a idade da planta. O córtex da raiz acumula o maior teor de ácido cianídrico, e a polpa da raiz o menor. Por ocasião da colheita, aos 360 dias após o plantio, essa cultivar é classificada como mandioca mansa

ROLE OF OXYTOCIN AND OXYTOCINASE IN THE MATERNAL RECOGNITION OF PREGNANCY

This thesis involved the investigation of luteal, endometrial and embryonic putative gene regulators in the maternal recognition of pregnancy in the horse, with an emphasis on understanding the role of oxytocin and oxytocinase in early pregnancy. The first objective was to validate the safety and health outcomes of mares following a transvaginal ultrasound-guided ovarian (TVOB) and serial luteal biopsy (TVLB), which was utilized as a means to obtain luteal tissue for gene expression studies without affecting pregnancy. The TVLB technique was determined to be safe and did not to affect pregnancy rate even after serial biopsy of the equine corpus luteum. The accuracy of the luteal biopsy technique was validated with histology, serial serum progesterone analysis and by gene expression studies using Aromatase, which is only expressed in luteal tissue and not in the adjacent ovarian stroma. We concluded TVLB was a safe and useful tool when studying luteal events in equine pregnancy. The second objective was to determine the effect of intrauterine administration of plant oils, such as coconut oil, on equine luteal function. A previous report using intrauterine infusion of a bioidentical coconut oil, product prolonged luteal function. The infusion of coconut oil during diestrus shortened the luteal phase in the mare, demonstrating that plant oil was not effective in keeping mares out of heat. The third objective was to characterize serum and tissue oxytocinase (LNPEP) in mares, especially during early and late pregnancy and to characterize the expression of oxytocin (OXT) in reproductive tissues. Serum LNPEP did not differ between pregnant and nonpregnant mares, or between late prepartum and immediately post-partum period. Tissue LNPEP was widely distributed among the reproductive tissues of the mare, including the placenta. Oxytocin was demonstrated to be expressed in the equine corpus luteum, but not in the endometrium or myometrium. This chapter described the presence of oxytocin and oxytocinase and their importance in reproductive function in the mares. The fourth objective was to compare the equine endometrial and luteal gene expression in mares that either were treated pharmacologically or naturally induced to have prolonged or shortened luteal phases. This series of experiments included six groups: pregnant mares, nonpregnant diestrous mares, estrous mares, mares treated with carbetocin, oxytocin, and meclofenamic acid. Both OXT and LNPEP were expressed in the equine luteal tissue. Carbetocin-treated mares had similar gene expression profiles to estrous mares and had an increased expression of endometrial phospholipase A2 (PLA2G2C) and a decreased expression of both endometrial and luteal prostaglandin E synthase (PTGES). Furthermore, PTGES expression was higher in diestrous, pregnant and oxytocin treated mares, suggesting that prostaglandin E (PGE) may have a luteoprotective role. To further characterize the gene expression during expected time of MRP, the fifth objective focused on comparing endometrial and luteal gene expression of pregnant and nonpregnant mares in different days of the cycle: Day (D)8, D10, 12 and 15. Endometrial and luteal PTGES have an increased mRNA abundance in both diestrous and pregnant mares, further supporting the luteotrophic role of PGE for luteal maintenance. Lastly, the sixth objective was to compare the trophoblastic gene expression on Day 8 through D21 and to immunolocalize OXT and LNPEP in the equine embryo. Prostaglandin synthase 2 (PTGS2) was increased in D14, D15 and D21 embryos; prostaglandin F receptor (PTGFR) was increased from D8 to D12-21; and LNPEP was increased at D15 compared to D10. Oxytocin was not detected by either immunohistochemistry (IHC), the RNAscope technique or by liquid chromatography tandem mass spectrometry (LC-MS/MS). The presence of LNPEP was confirmed with IHC and LC-MS/MS

Expression of Oxytocin/Neurophysin I and Oxytocinase in the Equine Conceptus from Day 8 to Day 21 Post-Ovulation

Leucyl and cystinyl aminopeptidase (LNPEP/oxytocinase) is an enzyme that metabolizes oxytocin in serum and tissues. The presence of oxytocin/neurophysin I (OXT), oxytocin and LNPEP and their relationship to other genes is unknown in the equine conceptus. Our objective was to characterize gene expression of LNPEP and OXT on D8, 10, 12, 14, 15, 16 and 21 conceptuses in relationship to other genes. Immunohistochemistry, western blot and liquid chromatography with tandem mass spectrometry (LC-MS/MS) were used for identification of oxytocin and LNPEP in D15, 16 and 18 conceptuses. LNPEP was increased at D15 compared to D10, was immunolocalized in the equine trophectoderm and endoderm, and protein was confirmed by LC-MS/MS. Maximal abundance of OXT was at D21, and lowest on D12 and D14, but no protein was identified. OXTR abundance was highest on D14 and D21. LNPEP was correlated with PTGFR and PTGES on D12 and D14–D15, and high expression of PTGES, PTGS2 was found on D14, D15 and D21; PTGFR was found on D8 and D12–21. LNPEP may have a role in prostaglandin regulation and conceptus fixation by decreasing the availability of oxytocin. Further investigation on the role embryonic LNPEP during pregnancy is warranted

Expression of Oxytocin/Neurophysin I and Oxytocinase in the Equine Conceptus from Day 8 to Day 21 Post-Ovulation

Leucyl and cystinyl aminopeptidase (LNPEP/oxytocinase) is an enzyme that metabolizes oxytocin in serum and tissues. The presence of oxytocin/neurophysin I (OXT), oxytocin and LNPEP and their relationship to other genes is unknown in the equine conceptus. Our objective was to characterize gene expression of LNPEP and OXT on D8, 10, 12, 14, 15, 16 and 21 conceptuses in relationship to other genes. Immunohistochemistry, western blot and liquid chromatography with tandem mass spectrometry (LC-MS/MS) were used for identification of oxytocin and LNPEP in D15, 16 and 18 conceptuses. LNPEP was increased at D15 compared to D10, was immunolocalized in the equine trophectoderm and endoderm, and protein was confirmed by LC-MS/MS. Maximal abundance of OXT was at D21, and lowest on D12 and D14, but no protein was identified. OXTR abundance was highest on D14 and D21. LNPEP was correlated with PTGFR and PTGES on D12 and D14–D15, and high expression of PTGES, PTGS2 was found on D14, D15 and D21; PTGFR was found on D8 and D12–21. LNPEP may have a role in prostaglandin regulation and conceptus fixation by decreasing the availability of oxytocin. Further investigation on the role embryonic LNPEP during pregnancy is warranted