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The effect of a single injection of prostaglandin F2alpha (PGF) during mid-diestrus on systemic concentrations of progesterone, LH, FSH, estradiol, and cortisol and on blood flow to the corpus luteum was studied in 10 controls and 10 PGF-treated mares. Blood flow was assessed by estimating the percentage of corpus luteum with color-Doppler signals of blood flow during real-time scanning of the entire structure and by the diameter of the vascular pedicle near its attachment to the ovary. Treatment was done 8 days after ovulation and 0 h was immediately before the treatment. Examinations and collection of blood samples were done at 0 h, every 5 min until 1h, and then at 1.5, 2, 4, 8, 12, 24, 48, and 72 h. The concentrations of estradiol did not change, but progesterone, LH, FSH, and cortisol increased significantly within 5 min. Concentrations of LH and FSH in the PGF group remained elevated until a temporarily lower concentration at 8 or 4h, respectively, rebounded to 12h, and then slowly decreased. Cortisol remained elevated, until a decrease between 1 and 4h. Progesterone in the PGF group increased significantly until 10 min after 0 h and then decreased by 40 min to below the concentrations in controls. Within the PGF group, progesterone decreased significantly by 45 min to below the concentrations at 0 h. The values for each of the two indicators of blood flow did not differ significantly between the PGF and control groups until a decrease at 24h in the PGF group. Results did not support the hypothesis that the immediate transient post-PGF increase in progesterone was associated with an increase in luteal blood flow. Luteolysis, as indicated by decreasing progesterone, began well before the beginning of a decrease in luteal blood flow. 相似文献
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Bruna R. Curcio Melba O. Gastal Gabriel R. Pereira Carine D. Corcini Fernanda C. Landim-Alvarenga Severo S. Barros Carlos E.W. Nogueira João Carlos Deschamps Eduardo L. Gastal 《Journal of Equine Veterinary Science》2014
Ultrastructural morphological injuries and maturation rates were investigated in equine oocytes exposed to vitrification solutions (VS) containing synthetic ice blockers (SIBs) during different exposure times. In experiment 1, compact cumulus-oocyte complexes (COCs; n = 30) were randomly allocated to treatments: (1) fresh fixed (control); (2) VS-1 (1.4 M dimethyl sulfoxide [DMSO] + 1.8 M ethylene glycol [EG] + 1% SIB) for 3 minutes of equilibrium time and VS-2 (2.8 M DMSO + 3.6 M EG + 0.6 M sucrose + 1% SIB) for 1 minute (Eq-long); and (3) VS-1 for 1.5 minutes and VS-2 for 30 seconds (Eq-short). In experiment 2, compact (n = 248) and expanded (n = 264) COCs were evenly distributed to the following treatments: (1) immediate maturation in vitro (control); (2) vitrification using the Eq-short protocol as in experiment 1; and (3) vitrification using a stock solution containing 2.8 M formamide, 2.8 M DMSO, 2.7 M EG, 7% polyvinylpyrrolidone, and 1% SIB (Eq-short-mod). More (P < .02) oocytes with normal ultrastructural morphology were seen in fresh control and Eq-short groups than in Eq-long group. Metaphase-II (MII) rates were higher (P < .05) for oocytes with expanded cumulus than compact cumulus in the control group, and higher (P < .05) for oocytes with expanded cumulus than compact cumulus in Eq-short and Eq-short-mod groups. No difference in MII rates was detected among groups within each type of COC. In conclusion, reduction of exposure time to VS better preserved oocyte ultrastructural features, and MII rates were higher for vitrified oocytes with expanded cumulus. This study advances our knowledge on potential alternatives for vitrification of immature equine oocytes. 相似文献
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L. A. Silva DVM E. L. Gastal DVM M. O. Gastal DVM J. C. F. Jacob DVM C. P. Reis DVM O. J. Ginther VMD 《Journal of Equine Veterinary Science》2004,24(8):324-332
A transvaginal ultrasound-guided intrauterine injection (IUI) technique was developed for embryo transfer and for injection of small quantities of sperm in mares. The target area of a horn was positioned by transrectal manipulation against the wall of the vaginal fornix over the face of a transvaginal transducer. A needle with a catheter containing the embryo or semen was inserted through the needle guide of the transducer into the uterine lumen. The tips of the needle and catheter, the movement of the catheter in the uterine lumen, and the ejection of fluid was monitored on the ultrasound screen. Pregnancy rate 15 days after ovulation for the IUI embryo transfer technique (30/39, 77%) was similar to the pregnancy rate for transcervical (TC) embryo transfer (30/38, 79%). The pregnancy rate for IUI insemination of 20 × 106 progressively motile sperm into the tip of the uterine horn ipsilateral to ovulation was 5/10 (50%). Results indicated that the IUI approach is a viable alternative for embryo transfer. Results also supported the potential of IUI for insemination of low numbers of sperm, but more extensive studies with various doses of sperm are needed. 相似文献
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Incidence, Endocrinology, Vascularity, and Morphology of Hemorrhagic Anovulatory Follicles in Mares 总被引：3，自引：2，他引：1
O.J. Ginther VMD PhD E.L. Gastal DVM PhD M.O. Gastal DVM PhD M.A. Beg DVM PhD 《Journal of Equine Veterinary Science》2007,27(3):130-139
The incidence of hemorrhagic anovulatory follicles (HAFs) is approximately 5% and 20% of estrous cycles during the early and late ovulatory season, respectively. The structures are more common in old mares (eg, >20 years), tend to occur repeatedly in individuals, and occur most frequently during the late follicular phase. In a recent study, the day of ovulation in controls and the first day of HAF formation, as indicated by cloudiness of follicular fluid, were defined as day 0. On day -1, future ovulating and HAF groups did not differ in follicle diameter or in the frequency of discrete gray-scale ultrasonic indicators of impending ovulation; however, in future HAFs, a greater percentage of the circumference of the follicle exhibited color-Doppler signals of blood flow. No differences were found between the two groups in systemic concentrations of progesterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) on days -4 to 2, but estradiol was elevated in the HAF group on day -3. The wall of the HAFs developed well-vascularized luteal tissue as indicated by echotexture and color Doppler signals and by the production of near normal levels of progesterone. In conclusion, HAFs formed from viable preovulatory follicles that did not differ from ovulatory follicles in diameter or gray-scale echotexture. Estradiol concentrations were elevated a few days before the failure of ovulation, and the wall of the follicle was more extensively vascularized on day -1. 相似文献
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O.J. Ginther VMD PhD E.L. Gastal DVM PhD M.O. Gastal DVM PhD 《Journal of Equine Veterinary Science》2007,27(1):20-27
Color Doppler and B-mode film clips were taken of the preovulatory follicle an hour before the beginning of ovulation. Locations of serrated granulosa and color-flow signals were determined by clock-face positions with the apex of the follicle (future ovulation site) at 12 o'clock. Mares were divided into a group with normal follicle evacuation (completion within 1 hour; n = 21 mares) and a group with septated evacuation (n = 5). The septated group was characterized by completion of evacuation in ≥3 hours and formation of echoic trabeculae in the antrum during evacuation. The trabeculae in the septated evacuations contained blood-flow signals and were interpreted to be creases in the slowly collapsing follicle wall. In the normal-evacuation group, serration and blood-flow signals were located at the basal hemisphere of the follicle directly opposite to the apex, and the o'clock positions did not differ significantly between the two characteristics. The apical area was devoid of both serration and color-flow signals. Vascularization of the corpus luteum began at the basal third on the day of ovulation and reached the apical third in a mean of 5.5 days. In septated evacuation, color-flow signals were detected at every clock-face position in each mare at the hour before ovulation. Results supported the following hypotheses: (1) both granulosa serration and color-flow signals occur in a similar basal area opposite to the apex; and (2) prolonged septated follicle evacuation is associated with vascularization of a greater circumference of the follicle than for normal evacuation and includes the apical area. 相似文献
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Mahieu Stéphanie Novak Sandra Barre Philippe Delagarde Rémy Niderkorn Vincent Gastal François Emile Jean-Claude 《Agroforestry Systems》2021,95(7):1295-1308
Agroforestry Systems - In temperate regions, tree leaves could be a source of energy, protein, vitamins and minerals for ruminants. Our objective was to study the diversity in chemical composition... 相似文献
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Effective indicators of plant nitrogen (N) nutrition are needed to improve N management in grasslands. This is particularly the case for mixtures that rely on N fixation by legumes as a major N input, because no reference tool such as the nitrogen nutrition index (NNI) exists under these conditions. The aims of this study were to test the reliability of a plant-based index, the N concentration of upper leaves in the canopy (Nup), as a possible alternative for NNI in both pure and mixed grasslands. Data were gathered from four experiments covering a range of pure and mixed grasslands under different N fertilization levels. A cross-validation of Nup predictions against NNI in pure stands, and against two NNI-derived indices in mixtures, was performed. The Nup values appeared to be linearly related to NNI in pure stands of both grasses and legumes. The relationship was identical for the two groups of species and explained up to 86% of NNI variability. In mixtures, Nup also displayed a linear relationship with the two other tested indices, explaining 65% and 78% of variability. The conclusions of the three indices diverged with respect to strongly unbalanced mixtures, where the assumptions regarding the computation of NNI-derived indices were not met. Excluding these situations, the overall relationship between Nup and NNI proved to be identical for mixtures and pure stands. The results suggest that Nup is a valid criterion for plant N nutrition which applies to a broad range of grassland species and to mixture conditions. 相似文献