Effects of intrauterine devices on proteins in the uterine lavage fluid of mares

Intrauterine devices block luteolysis in cyclic mares, but the underlying mechanism is unknown. To clarify the mechanisms, the protein profile of the endometrial secretome was analyzed using two-dimensional difference gel electrophoresis (2D-DIGE). Twenty-seven mares were classified according to whether they were inseminated (AI) or had an intrauterine device (IUD), a water-filled plastic sphere, inserted into the uterus on Day 3 after ovulation. Uterine lavage fluids were collected on Day 15 from pregnant inseminated mares (AI-P; n = 8), non-pregnant inseminated mares (AI-N; n = 4), and mares with IUD (n = 15). The IUD group was further divided into prolonged (IUD-P; n = 7) and normal luteal phase (IUD-N; n = 8) groups on the basis of ultrasound examinations, serum levels of progesterone and PGFM on Days 14 and 15, and COX-2 results on Day 15. Four mares from each group were selected for the 2D-DIGE analyses. Ten proteins had significantly different abundance among the groups, nine of the proteins were identified. Malate dehydrogenase 1, increased sodium tolerance 1, aldehyde dehydrogenase 1A1, prostaglandin reductase 1, albumin and hemoglobin were highest in pregnant mares; T-complex protein 1 was highest in non-pregnant mares; and annexin A1 and 6-phosphogluconolactonase were highest in IUD mares. The results suggest that the mechanism behind the intrauterine devices is likely related to inflammation.Peer reviewe

Inflammatory Markers in Uterine Lavage Fluids of Pregnant, Non-Pregnant, and Intrauterine Device Implanted Mares on Days 10 and 15 Post Ovulation

Intrauterine devices (IUDs) are used in mares to suppress oestrous behaviour, but the underlying mechanism is yet to be elucidated. The presence of an embryo or an IUD prevents cyclooxygenase-2 (COX-2) and, subsequently, prostaglandin (PG) release and luteolysis. However, inflammation may also be involved. Endometrial inflammatory markers in uterine lavage fluid were measured on Day 10 (EXP 1, n = 25) and Day 15 (EXP 2, n = 27) after ovulation in inseminated mares, non-pregnant or pregnant, and in mares in which a small plastic sphere had been inserted into the uterus 4 (EXP 1) or 3 days (EXP 2) after ovulation. Uterine lavage fluid samples were analysed for nitric oxide (NO), prostaglandin E2 (PGE2) (only EXP 1), prostaglandin F2α (PGF2α), inhibin A and cytokines, and blood samples for progesterone and oestradiol. On Day 10, the concentration of PGF2α was lower (p < 0.05) in the IUD group than in pregnant mares. The concentration of the modulatory cytokine IL-10 was significantly higher in the IUD group in comparison to non-pregnant mares, and inhibin A was significantly higher in IUD mares than in the pregnant counterparts on Day 15. The results suggest that the presence of IUD causes endometrial inflammation which is at a resolution stage on Day 15

Inflammatory Markers in Uterine Lavage Fluids of Pregnant, Non-Pregnant, and Intrauterine Device Implanted Mares on Days 10 and 15 Post Ovulation

Intrauterine devices (IUDs) are used in mares to suppress oestrous behaviour, but the underlying mechanism is yet to be elucidated. The presence of an embryo or an IUD prevents cyclooxygenase-2 (COX-2) and, subsequently, prostaglandin (PG) release and luteolysis. However, inflammation may also be involved. Endometrial inflammatory markers in uterine lavage fluid were measured on Day 10 (EXP 1, n = 25) and Day 15 (EXP 2, n = 27) after ovulation in inseminated mares, non-pregnant or pregnant, and in mares in which a small plastic sphere had been inserted into the uterus 4 (EXP 1) or 3 days (EXP 2) after ovulation. Uterine lavage fluid samples were analysed for nitric oxide (NO), prostaglandin E2 (PGE2) (only EXP 1), prostaglandin F2α (PGF2α), inhibin A and cytokines, and blood samples for progesterone and oestradiol. On Day 10, the concentration of PGF2α was lower (p < 0.05) in the IUD group than in pregnant mares. The concentration of the modulatory cytokine IL-10 was significantly higher in the IUD group in comparison to non-pregnant mares, and inhibin A was significantly higher in IUD mares than in the pregnant counterparts on Day 15. The results suggest that the presence of IUD causes endometrial inflammation which is at a resolution stage on Day 15

Importance of Water Transport in Mammalian Female Reproductive Tract

Aquaporins (AQPs) are involved in water homeostasis in tissues and are ubiquitous in the reproductive tract. AQPs are classified into classical aquaporins (AQP0, 1, 2, 4, 5, 6 and 8), aquaglycerolporins (AQP3, 7, 9, and 10) and superaquaporins (AQP11 and 12). Nine AQPs were described in the mammalian female reproductive tract. Some of their functions are influenced by sexual steroid hormones. The continuous physiological changes that occur throughout the sexual cycle, pregnancy and parturition, modify the expression of AQPs, thus creating at every moment the required water homeostasis. AQPs in the ovary regulate follicular development and ovulation. In the vagina and the cervix, AQPs are involved mainly in lubrication. In the uterus, AQPs are mostly mediated by estradiol and progesterone to prepare the endometrium for possible embryo implantation and fetal development. In the placenta, AQPs are responsible for the fluid support to the fetus to maintain fetal homeostasis that ensures correct fetal development as pregnancy goes on. This review is focused on understanding the role of AQPs in the mammalian female reproductive tract during the sexual cycle of pregnancy and parturition

Cyclooxygenase-2 is inhibited in prolonged luteal maintenance induced by intrauterine devices in mares

Treatment with intrauterine devices (IUD) prolongs luteal phases in mares, but the mechanism for this has not been fully elucidated. The aims of the present study were to examine how IUDs affect the uterus to induce longer luteal phases, particularly the role of cyclooxygenase-2 (COX-2) in the maintenance of the corpus luteum (CL). Twenty-seven reproductively normal mares were included: 12 were inseminated (AI), and 15 were fitted with IUDs. Blood samples for progesterone were obtained on Days 0, 3, 5, 7, 9, 11, 13, 14, and 15 (relative to day of ovulation). The groups were further divided into non-pregnant (AI-N, n = 4), pregnant (AI-P, n = 8), normal (IUD-N, n = 8) and prolonged luteal phase (IUD-P, n = 7) based on ultrasonic examinations and serum progesterone concentrations on Days 14 and 15. Blood sampling to quantify the PGF(2 alpha) metabolite (PGFM) was performed through a catheter hourly from 15:00 to 20:00 h on Day 14, and from 6:00 until 13:00 h on Day 15. On Day 15, a low-volume uterine lavage followed by an endometrial biopsy was performed. Estradiol concentration in the Day 15 serum and lavage fluid was determined, while the abundance of COX-2 was evaluated in the biopsy specimens using western blotting (WB) and irnmunohistochemistry (IHC). All pregnant mares were negative for COX-2 in IHC samples and 5 of 8 were negative in WB samples while all mares of the IUD-N group were positive for COX-2. Of the seven mares in the IUD-P group, five and four were negative for COX-2 with the IHC and WB samples, respectively. The results from this study indicate that IUDs, when effective, suppress COX-2, leading to the inhibition of PGF2 alpha release and maintenance of CL.Peer reviewe

Mechanisms behind intrauterine device-induced luteal persistence in mares

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Effects on the equine endometrium of cervical occlusion after insemination

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Evaluation of the Probiotic In Vitro Potential of Lactic Acid-Producing Bacteria from Canine Vagina: Possible Role in Vaginal Health

Lactic acid-producing bacteria (LAB) are being widely studied due to their probiotic potential. The aim of the present study was to determine and identify the presence of LAB from canine vaginal samples, as well as to evaluate their probiotic in vitro potential. Ninety-four bitches were included in the study. Vaginal samples were obtained by means of a sterile swab and streaked on Man Rogosa Sharpe agar plates. A total of 100 LAB strains were obtained and submitted to Gram stains and basic biochemical tests, which included catalase, oxidase and haemolysis tests. Thirteen strains belonging to the genera Lactobacillus (n = 10), Lactococcus (n = 2) and Pediococcus (n = 1) were selected as potential probiotics and further subjected to evaluation of resistance to gastrointestinal conditions (pH, lysozyme, bile salts and hydrogen peroxide) and safety and efficacy in vitro (resistance to antibiotics and antimicrobial capacity). Only three strains, one Lactobacillus lactis and two Lactobacillus plantarum, accomplished the requirements for being considered as potential in vitro probiotics