Peri-estrus ovarian, uterine, and hormonal variables determine the uterine luminal fluid metabolome in beef heifers.

In cattle, uterine luminal fluid (ULF) is the main source of molecules that support embryo development and survival during the peri-implantation period. Our overarching hypothesis is that peri-estrus changes in uterine function, including ULF accumulation and absorption, are uneven among individuals, and affect ULF composition and fertility. Our objectives were (1) to characterize temporal and spatial changes in ULF volume, endometrial and luteal blood perfusion, endometrial and luteal size, and circulating progesterone concentrations during the peri-estrus period in beef heifers and (2) to associate such changes with the metabolite composition in the ULF, 4 days after estrus (d 0). Fourteen Bos indicus heifer that presented a PGF2α responsive CL received 500 µg PGF2α analog i.m. and were examined daily by rectal B-mode and pulse-wave color-Doppler ultrasonography until the fifth day after estrus (d 5). The composition of the ULF was analyzed by targeted mass spectrometry on d 4. Multivariate analyses clustered heifers according to ovarian, uterine, and hormonal variables in clusters A (n = 5) and B (n = 8 heifers). Concentrations of Pro, Ala, Leu, Gly, Val, Lys, Ile, Phe, Asp, Orn, Tyr, Arg, Trp, Suc, Cit, ADMA, the sum of essential Amino Acids (AA), sum of nonessential AA, sum of aromatic AA, and total AA were greater in cluster A (FDR ≤ 0.05). ULF volume dynamics and uterine, ovarian, and hormonal variables during the peri-estrus period presented a concerted variation among heifers within clusters, which was associated with the ULF composition 4 days after estrus.

Melatonin and CIDR improved the follicular and luteal haemodynamics, uterine and ovarian arteries vascular perfusion, ovarian hormones and nitric oxide in cyclic cows.

This study hypothesizes that melatonin with exogenous progesterone (CIDR) can improve follicular, luteal, ovarian and uterine haemodynamic of heat-stressed cows. Holstein cows (N = 12) studied for two spontaneous oestrous cycles during winter then divided equally during summer into the CIDR group received CIDR for 7 days and the melatonin group (Mel) received three injections of melatonin (75 mg/head) at the CIDR insertion, removal and ovulation days. Blood samples were collected to assay oestradiol (E2), progesterone (P4) and nitric oxide (NO). On day 0 (Ovulation), Mel had more small follicles (p < .05), higher ipsilateral and contralateral ovarian arteries (Ov.A.) peak systolic velocity (PSV), higher ipsilateral uterine artery (Ut.A.) PSV (p = .031) and blood flow volume (BFV), also Mel elevated contralateral Ut.A. PSV and BFV (p < .0001) but lowered contra Ut.A. pulsatility index (PI, p < .0001), E2 (p < .01) and NO (p < .0001). Mel increased the corpus luteum diameter (CL, p < .001), coloured area (p < .007) and P4 (p < .0001) on day 5 and reduced them (p < .05; p < .01) on Day 14. On day 10, Mel obtained CL diameter (p < .03) and coloured area (p < .002) of spontaneous that was higher than CIDR and decreased P4 (p < .003). Mel increased CL diameter, area and coloured area and decreased them thereafter. Mel increased the ipsilateral ovarian and uterine arteries PSV and BFV before ovulation and until day 8. Mel increased P4 and decreased NO until days 6 and 14. In conclusion, the improvement in follicular, luteal, ovarian and uterine haemodynamic and the decrease of NO production proved our hypothesis Melatonin doses higher than 75 mg/head is recommended to improve the heat-stressed cow's fertility.

Hypoxia-inducible factor-1alpha and nitric oxide synthases in bovine follicles close to ovulation and early luteal angiogenesis.

The objective of the study was to characterize expression patterns of hypoxia-inducible factor-1alpha (HIF1A), inducible nitric oxide synthase (iNOS) and endothelial (eNOS) isoforms in time-defined follicle classes before and after GnRH application in the cow. Ovaries containing pre-ovulatory follicles or corpora lutea were collected by transvaginal ovariectomy (n = 5 cows/group) as follow: (I) before GnRH administration; (II) 4h after GnRH; (III) 10h after GnRH; (IV) 20h after GnRH; (V) 25h after GnRH; and (VI) 60h after GnRH (early corpus luteum). The mRNA abundance of HIF1A in the follicle group before GnRH was high, followed by a significant down regulation afterwards with a minimum level 25h after GnRH (close to ovulation) and significant increase only after ovulation. The mRNA abundance of iNOS before GnRH was high, decreased significantly during LH surge, with minimum levels afterwards. In contrast, the mRNA of eNOS decreased in the follicle group 20h after GnRH, followed by a rapid and significant upregulation just after ovulation. Immunohistochemically, the granulosa cells of antral follicles and the eosinophils of the theca tissue as well of the early corpus luteum showed a strong staining for HIF1A. The location of the eosinophils could be clearly demonstrated by immunostaining with an eosinophil-specific antibody (EMBP) and transmission electron microscopy. In conclusion, the parallel and acute regulated expression patterns of HIF1A and NOS isoforms, specifically during the interval between the LH surge and ovulation, indicate that these paracrine factors are involved in the local mechanisms, regulating final follicle maturation, ovulation and early luteal angiogenesis.

Immunoexpression of cytokine tumour necrosis factor-α suggesting its role in formation and regression of corpus luteum in Indian buffalo.

Tumour necrosis factor-α (TNF-α) is a cytokine that plays multiple important roles in corpus luteum (CL). Immunolocalization of expression of TNF-α in CL of buffalo was studied in different stages of its development and regression. Corpus luteum of healthy buffaloes (24) was collected from local slaughterhouses and categorized into early (stage I, 1-5 days, n = 6), mid (stage II, 6-11 days, n = 6), late luteal (stage III, 12-16 days, n = 6) and regressing phase (stage IV, 17-20 days, n = 6). In earliest phase of cyclic CL, per cent immunoexpression of TNF-α was significantly (p < .05) lower as compared to all phases with its expression being restricted to few developing luteal cells, usually in neutrophils. A significantly (p < .05) higher number of neutrophils with TNF-α immunoexpression were observed as compared to mid-luteal phase that indicated its role in initiation of angiogenesis at this stage. TNF-α immunoexpression almost doubled in mid-luteal phase, but the number of neutrophils exhibiting TNF-α was significantly (p < .05) lower with respect to all phases of CL. Immunoexpression percentage in late luteal phase increased sharply being significantly (p < .05) higher than earlier two phases of CL. In regressing phase, per cent immunostaining was maximum with highly significant (p < .05) difference as compared to all other stages, observed in all degrading luteal cells, abundant immune cells, that is neutrophils and macrophages which finally led to apoptosis and phagocytosis. Immunoexpression of TNF-α in early luteal phases served its role in initiation of angiogenesis, and its intense expression in regressing phase of CL suggested a shift in its role to apoptosis and structural luteal regression signifying both luteotropic and luteolytic roles in buffalo. This is probably the first study of its kind in buffaloes.

Luteal blood flow as a predictive factor for methotrexate treatment outcomes in women with unruptured tubal pregnancy.

BACKGROUND: Blood flow in the corpus luteum is associated with luteal function. However, the impact of luteal blood flow on methotrexate (MTX) treatment in women with unruptured tubal pregnancy has not been reported. The aim of the present study was to observe the impact of luteal blood flow on the therapeutic effect of MTX in women with unruptured tubal pregnancy. METHODS: A prospective observational study recruited 129 women with unruptured tubal pregnancy in the First Affiliated Hospital of Xi'an Jiaotong University from September 2016 to June 2018. One hundred and fifteen women were treated successfully with MTX, and women were divided into 2 groups according to luteal blood flow: the poor luteal blood flow group and the abundant luteal blood flow group. The therapeutic effects were compared between the two groups. RESULTS: Women in the abundant luteal blood flow group had a significantly higher serum ß-human chorionic gonadotropin (ß-hCG) level 4 days, 1 week and 2 weeks after MTX treatment compared with women in the poor luteal blood flow group (P < 0.05). The average diameter of the ectopic mass 1 week, 2 weeks and 3 weeks after MTX treatment in women with abundant luteal blood flow was significantly larger (P < 0.05), and the time of serum ß-hCG clearance and ectopic mass disappearance were significantly longer compared with those in women in the poor luteal blood flow group (P < 0.05). CONCLUSIONS: Luteal blood flow might be a predictive factor for MTX treatment outcomes in women with unruptured tubal pregnancy, and those with abundant luteal blood flow need a longer recovery time.

Spectral Doppler ultrasound in selecting an equine embryo receiver.

The aim of this study was to evaluate whether the RI and PI values would help in choosing the best embryo recipient, and observe whether CL vascularization would influence P4 production. During the breeding season 2018/2019, the study was conducted using 35 mares, which is used for reference to collect data for the project on the day of embryo transfer. The utilized mares were divided into five groups followed by the day after ovulation, with D0 being the day of ovulation. Therefore, the five groups are as follows: D4-mares that were on the 4th post-ovulation day; D5-mares that were on the 5th post-ovulation day; and doing so successively for D6, D7 and D8. On the day of embryo transfer, the CL of the mares that selected as recipients was evaluated by B-mode and power flow mode ultrasonography and the right and left dorsal branches of the uterine arteries by spectral Doppler ultrasonography. Blood samples were taken on the day of the embryo transfer for a dosage of P4 concentration by radioimmunoassay. No statistical difference was found between the variables when the mares were separated into pregnant and non-pregnant mares, or when they were separated by age groups. When the groups of mares were compared by the day of embryo transfer, the statistical difference was found between the groups D5 × D6 (p = .0053) and D6 × D8 (p = .0036) in RI variable. In PI variable, the statistical difference was found between the groups D4 × D8 (p = .049), D5 × D6 (p = .0446) and D6 × D8 (p = .0024). We conclude that the mares with RI measurement of uterine arteries near 1.0 are correlated to mares with high CL vascularization and elevated P4 concentration.

Detrimental effects of uterine disease and lipopolysaccharide on luteal angiogenesis.

Reproductive tract inflammatory disease (RTID) commonly occurs after the traumatic events of parturition and adversely affects follicular function. This study is the first to describe the cellular and steroidogenic characteristics of corpora lutea from cattle with RTID and the effects of pathogen-associated molecular patterns (PAMPs) on luteal angiogenesis and function in vitro. Luteal weight (P < 0.05) and progesterone content (P < 0.05) were reduced (1.2-fold) in cows with RTID, accompanied by reduced CYP11A (P < 0.05), HSD3B (P < 0.01) and STAR (P < 0.01) protein expression. Immunohistochemistry revealed that luteal vascularity (VWF) and pericyte (ACTA2) coverage were >3-fold lower in RTID cows (P < 0.05). To link these observations to bacterial infection and determine specificity of action, a physiologically relevant luteal angiogenesis culture system examined the effects of PAMPs on endothelial cell (EC) network formation and progesterone production, in the presence of pro-angiogenic factors. Luteal EC networks were reduced ≤95% (P < 0.05) by lipopolysaccharide (LPS, toll-like receptor (TLR) 4 agonist) but not by TLR2 agonists lipoteichoic acid or peptidoglycan. Conversely, progesterone production and steroidogenic protein expression were unaffected by PAMPs (P > 0.05). Moreover, the adverse effect of LPS on luteal EC networks was dose-dependent and effective from 1 ng/mL (P < 0.05), while few EC networks were present above 10 ng/mL LPS (P < 0.001). LPS reduced proliferation (P < 0.05) and increased apoptosis of EC (P < 0.001). The specific TLR4 inhibitor TAK242 reversed the effects of LPS on EC networks. In conclusion, luteal vasculature is adversely sensitive to LPS acting via TLR4, therefore ovarian exposure to LPS from any Gram-negative bacterial infection will profoundly influence subsequent reproductive potential.

Corpus luteum vascularization during the maternal recognition of pregnancy in llamas (Lama glama).

The aim of this study was to characterize corpus luteum vascularization and its association with plasma progesterone concentration in early stages of pregnancy, when maternal recognition of pregnancy is expected to occur. In all animals, both plasma progesterone concentration and corpus luteum vascularization increased from Day 6 to Day 8 post-mating and afterwards in non-pregnant llamas they started to decrease to reach basal levels around Days 12 to 14 post-mating, while in pregnant animals, both variables remained elevated until the end of the study. A lineal positive relationship between corpus luteum vascularization and plasma progesterone concentration was observed in pregnant (r2  = .46, p < .0001) and non-pregnant llamas (r2  = .66, p < .0001). Pregnant animals showed higher plasma progesterone concentration and corpus luteum vascularization than the non-pregnant ones from Day 12 post-mating until the end of the study (p Ë‚ .05 and p Ë‚ .01, respectively). These results suggest that maternal recognition of pregnancy should occur before Day 12 post-mating in order to expand luteal lifespan, maintaining corpus luteum vascularization and progesterone production. Also, the assessment of CL vascularization area could be a useful and non-invasive method for early pregnancy diagnosis due to its association with plasma progesterone concentration.

Accuracy of subjective evaluation of luteal blood flow by color Doppler ultrasonography for early diagnosis of pregnancy in Egyptian buffalo.

The objective of the current study was to evaluate the accuracy of trans-rectal color Doppler ultrasonography for early diagnosis of pregnancy in Egyptian buffalo based on subjective assessment of luteal blood flow (LBF). After timed artificial insemination (TAI), a total of 112 pluriparous buffalo were subjectively evaluated for LBF and there were score scales or grades (I-IV) determined at different times (Days 6, 14, 17, 21) post-TAI. Another trans-rectal B-mode ultrasonography of the uterus was performed at Day 35 to confirm pregnancy diagnosis based on recognition of the positive signs of pregnancy. Retrospectively, the results of B-mode ultrasonography were compared to that of the subjective evaluations of LBF for determining accuracy values. Furthermore, serum progesterone (P4) concentrations were determined as an indicator of corpora lutea (CL) function. Results indicate 68 of 112 buffalo (60.7%) were diagnosed as pregnant. The accuracy value of the LBF subjective evaluation was significant (80.4%; P <  0.05) at Day 17, and there was the maximum accuracy (96.4%) at Day 21 post-TAI. The percentage of false diagnoses was less at Days 17 and 21 compared with Day 6 and 14 post-TAI. There was a significant matching value between P4 concentrations and scores for LBF on and after Day 17 post-insemination. In conclusion, subjective evaluation of LBF using color Doppler ultrasonography is considered an accurate technique for early detection of pregnancy in Egyptian buffalo especially the non-pregnant animals as early as Day 17, with maximum accuracy at Day 21 post-TAI.

Luteal Blood Flow and progesterone concentration during first and second postpartum estrous cycle in lactating dairy cows.

The aim of the present study was to determine the differences in corpus luteum (CL) functionality between the first postpartum estrous cycle and the following cycle in lactating dairy cows. Luteal blood flow (LBF), luteal size and blood progesterone (P4) concentration were monitored during the first and second postpartum estrous cycle. During the first and second postpartum estrous cycle, the mean LBF value increased (p < .05) from early to late dioestrus, while it decreased rapidly in proestrus, resulting statistically lower (p < .05) than those registered in all previous phases. Statistically significant differences were not observed between overall LBF during first and second postpartum estrous cycle (p > .05). During the first postpartum estrous cycle, P4 blood concentrations showed a significant reduction (p < .05) from dioestrus to proestrus. A different trend of P4 concentrations was observed during the second postpartum estrous cycle, where mean P4 value registered in proestrus resulted statistically lower than those registered in the previous cycle phases (p < .05). The mean P4 concentration registered over the first postpartum estrous cycle resulted statistically lower (p < .05) than that registered during the second one. A significant correlation between P4 concentrations and LBF was registered only during the second postpartum estrous cycle. Results indicate that during the first postpartum estrous cycle, P4 concentration was independent of luteal blood flow and luteal size.

An objective volumetric method for assessment of ovarian follicular and luteal vascular flow using colour Doppler ultrasonography.

Our goal was to develop an objective computer-assisted volumetric method of assessing vascular flow from colour Doppler ultrasound data of ovarian structures recorded by free-hand movement. We hypothesized that a vascularity index (ratio of the region of blood flood to the region of ovarian structure) obtained from the three-dimensional volumetric analysis would be more precise (less variable) than conventional two-dimensional analysis of single images in estimating the functional status of the preovulatory follicles and corpus luteum. Doppler ultrasound cineloops of water buffaloes (Bubalus bubalis; n = 22) ovaries were recorded daily from 12 h before GnRH treatment to four days after ovulation. Cineloops were processed using Fiji and Imaris software packages for segmenting the area (two-dimensional analysis) and the volume (three-dimensional analysis) occupied by the blood-flow and associated tissue to calculate the vascularity index. For volumetric measurement, all images in a cineloop were used (i.e., no a-priori selection of images) while for two-dimensional analysis, three images from the region with apparent maximum vascularity were selected. The volumetric method was verified with theoretical ellipsoidal volume of the follicle (r = 0.96 P < 0.01) or corpus luteum (r = 0.58 P = 0.02). The variability in the follicular vascularity index among animals was lower using the volumetric method than two-dimensional analysis (0.018 ±â€¯0.002 vs 0.030 ±â€¯0.005, P < 0.01), while the variability for CL vascularity was similar between methods (P = 0.23). An increase in the follicular vascularity index was detected at 12 h after GnRH treatment using both methods (two-dimensional: 0.030 ±â€¯0.008, P < 0.01; three-dimensional: 0.016 ±â€¯0.006, P < 0.02). Buffaloes that ovulated tended to have a greater increase in 3D vascularity index than non-responding buffaloes (P = 0.06); the two-dimensional method was not able to detect these changes. Using the three-dimensional method, a moderate positive correlation (r = 0.59; P = 0.02) was evident between the follicular vascularity index at 14-16 h after GnRH treatment and follicular diameter. In conclusion, an objective volumetric method for assessing relative ovarian blood flow changes was developed using Doppler ultrasound cineloops recorded by free-hand movement. The 3-dimensional method eliminates the need for a-priori selection of images and is more precise as a result of decreased technical variability.

Vascular and morphological features of the corpus luteum 12 to 20 days after timed artificial insemination in dairy cattle.

Our objective was to retrospectively compare pregnant versus nonpregnant cattle in terms of vascular and morphometric changes in corpora lutea between d 12 and 20 following timed artificial insemination (TAI). Crossbred (Gir × Holstein) lactating dairy cows (n = 136) and heifers (n = 111) were bred after synchronizing ovulations using an estradiol plus progesterone (P4)-based protocol. Corpus luteum (CL) characteristics (area, echotexture, blood flow) were recorded at 48-h intervals from d 12 to 20 following TAI using an ultrasound equipped with color Doppler. Blood samples were collected to determine CL function (plasma P4). Pregnancy diagnosis was performed at d 30. Quantitative assessment of colored pixels within the CL was performed using ImageJ software (National Institutes of Health, Bethesda, MD) and echotexture was quantified using custom software. Continuous variables such as luteal tissue area (LTA), CL blood flow (CLBF), adjusted CLBF (ratio LTA:CLBF), mean pixel value (MPV), pixel heterogeneity (HETER), and plasma P4 were analyzed retrospectively as repeated measures (d 12 to 20) in pregnant versus nonpregnant females using PROC MIXED (SAS Institute Inc., Cary, NC). Main effects were pregnancy status, day of cycle, and their interaction. Further analyses used only data from d 16, because this was the earliest time point of deviation between CLBF of pregnant and nonpregnant animals. We created quartiles for each variable and calculated the risk of pregnancy within quartile. Differences were determined using the chi-squared test. Plasma P4 was significantly higher in prospective pregnant versus nonpregnant cattle on d 18 and 20, whereas LTA differed only on d 20. On d 16, CLBF and adjusted CLBF diverged between pregnant and nonpregnant, followed by a progressive reduction in the latter until d 20. Mean pixel value was not affected by pregnancy status, but HETER was lower on d 20 in pregnant than in nonpregnant cattle. Likelihood of pregnancy increased from quartile (Q)1 (lowest values) to Q4 (highest) of CLBF (Q4 vs. Q1, odds ratio = 32.8, 95% confidence interval: 9.6 to 112.1) and adjusted CLBF [Q4 vs. Q1, odds ratio = 25.4, 95% confidence interval: 8.1 to 80.4), whereas a lower risk of pregnancy was observed only for animals within Q1 of plasma P4 [Q4 vs. Q1, odds ratio = 3.1, 95% confidence interval: 1.3 to 7.2). Day 16 quartiles of LTA, MPV, and HETER did not affect odds of pregnancy. In conclusion, we identified distinct CLBF patterns as early as 16 d after TAI and confirmed that CL function is lost by a reduction in blood flow, which precedes physical regression.

A potential function of RLIP76 in the ovarian corpus luteum.

Ral interacting protein of 76 kDa (RLIP76) is multifunctional protein localized and distributed in the plasma membrane, cytosol, and nucleus of the cell. In tumorigenesis, RLIP76 emerges as a common feature for the solid tumor growth. RLIP76 is ubiquitously expressed in various tissues including the ovary. Interestingly, the similar physiological events in obtaining an adequate supply of nutrient by gaining access to the host vascular system are required either for corpus luteum formation or tumor development. In addition, the identical angiogenesis modulators were found in neoplastic and normal ovaries. Our previous study involving RLIP76-/- mice implanted with melanoma or carcinoma cell conclusively demonstrated that RLIP76 is necessary for angiogenesis and neovascularization of primary solid tumors. RLIP76 plays an essential role in tumor angiogenesis through the regulation of pro-angiogenic factors such as vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1 (HIF-1). In certain previous studies, those pro-angiogenic factors were found significantly to be upregulated during the corpus luteum formation. To that, the following review will discuss the likelihood of RLIP76 role in ovarian corpus luteum.

Luteal blood flow measured by Doppler ultrasonography during the first three weeks after artificial insemination in pregnant and non-pregnant Bos indicus dairy cows.

The objective of this study was to determine if there are differences in luteal size (LS), progesterone (P4), and luteal blood flow (LBF) between pregnant and non-pregnant Bos indicus dairy cows during the first three weeks after insemination, and whether these parameters are related to each other. Lactating cows (n = 13) of mixed parity with a body weight of 430 ± 18 kg (mean ± SD), showing regular estrous cycle were used in the study. All cows were artificially inseminated and were classified as pregnant (embryonic heartbeat on day 30; n = 8) or non-pregnant (inter-estrus interval 17 to 21 days, n = 5). In order to compare the LS and LBF after artificial insemination, B-mode and color Doppler ultrasonography of ovaries were performed on days 4, 5, 6, 7 (first week), 8, 10, 12, 14, (second week), and 16, 17, 18, 19, 20, 21 (third week) in pregnant and non-pregnant cows. Results revealed that the mean LBF was consistently higher (P < 0.05) during days 7 through 21 in pregnant cows than in non-pregnant cows. The mean LS was higher (P < 0.05) on days 6 and 7, and from day 17 onwards, and the mean concentration of P4 was higher (P < 0.05) on days 19, 20, and 21 in pregnant cows. In conclusion, LBF is a more sensitive parameter than LS and P4 for detection of differences in luteal function between pregnant and non-pregnant Bos indicus dairy cows during the first three weeks after AI.

Luteal ANGPT-TIE system during selected stages of pregnancy, and normal and antigestagen-induced luteolysis in the dog.

Abstract: Rapid establishment of a vascular network is essential for normal functionality of the corpus luteum (CL). The early luteal phase is associated with increased expression of the VEGF system in canine CL. Acting in synchrony with angiopoietins (ANGPTs), VEGF system plays major roles in stabilization of blood vessels. However, the expression of the ANGPT system has not yet been investigated in the dog. Therefore, here, we investigated the luteal expression of ANGPT1, -2, and of their receptors TIE1 and -2, in pregnant dogs at selected time points during pregnancy and at normal and antigestagen-induced luteolysis. Additionally, luteal cells from early CL were incubated with PGE2 and its effects on the ANGPT system were assessed. Whereas the luteal ANGPT1 was stable until mid-gestation, TIE1 was elevated post-implantation, their expression decreased toward prepartum luteolysis. The ANGPT2- and TIE2-mRNA did not vary during pregnancy. The ANGPT2/ANGPT1 ratio was elevated during prepartum luteolysis. PGE2 increased ANGPT2, but suppressed ANGPT1 levels. None of the ANGPT-system members was affected by antigestagen treatment in mid-pregnancy. Localization of ANGPT1 was predominantly found in the tunica intima and media of vessels and ANGPT2 stained strongly in luteal cells. Both ANGPTs were localized in macrophages. TIE1 stained in the vascular tunica media, in luteal cells and macrophages, whereas TIE2 was colocalized with ANGPT1 in vascular components. In conclusion, high expression of ANGPT1 during the increased presence of VEGFA in early canine CL implies its contribution to vascular network development. The upregulation of the ANGPT2/ANGPT1 ratio during prepartum luteolysis indicates involvement of the ANGPT system in PGF2α-mediated vascular destabilization.

Embryonic development, luteal size and blood flow area, and concentrations of PGF2α metabolite in dairy cows fed a diet enriched in polysaturated or polyunsaturated fatty acid.

The objective of this study was to examine effects of sunflower (SO) and palm oil (PO) supplements in the diet on embryonic development, luteal size and blood flow area, PGF2α metabolite (PGFM), and progesterone (P4) concentrations. Prepartum cows (n = 42) were randomly assigned to one of three dietary treatments (control, 4% PO, and 4% SO supplements). Animals were fed diets individually from day 28 prepartum to day 111 postpartum. Luteal size and blood flow area were determined throughout the estrous cycle by Doppler ultrasonography. Oocytes were collected in three ovum pick-up sessions at 2 week intervals for the in vitro embryo production. Oocyte characteristics and embryonic development were not affected by dietary treatments. Cows fed 4% SO had a greater (P < 0.05) concentration of PGFM from day 15 to day 35 postpartum than those cows fed 4% PO and the control group. On day 11 of the estrous cycle (mid-luteal phase), serum P4 concentrations (6.0 ±â€¯0.7, 5.7 ±â€¯0.5, and 4.7 ±â€¯0.6 ng/ml), luteal size (7.0 ±â€¯0.2, 6.5 ±â€¯0.2, and 5.3 ±â€¯0.1 cm2) and luteal blood flow area (1.3 ±â€¯0.2, 1.2 ±â€¯0.1, and 0.9 ±â€¯0.1 cm2) were greater (P < 0.05) in cows fed 4% SO and 4% PO than the control group, respectively. Thus, plant oil supplements in diets affected luteal size and serum P4 and PGFM concentrations, but not early embryonic development. Such changes in secretion of PGF2α and P4 indicate that plant oil supplements during pre- and postpartum may alter uterine and luteal functions.

Reproductive performance of Bos indicus beef cows treated with different doses of equine chorionic gonadotropin at the end of a progesterone-estrogen based protocol for fixed-time artificial insemination.

Two experiments were performed to evaluate the reproductive performance of zebu beef cows treated with different doses of eCG at the end of a progesterone (P4)/estrogen based protocol for timed artificial insemination (TAI). In Experiment 1, suckling Bos indicus Nelore cows (n = 261) received, on day 0, a progesterone (P4) intravaginal device (PD) and an injection of 1 mg estradiol benzoate (EB). On day 8, the PD was removed, 500 µg of cloprostenol was injected, and cows were assigned to one of the following groups: Control (no treatment), 300 (300 IU of eCG), 600 (600 IU of eCG), and 900 (900 IU of eCG). On day 9, all cows received 1 mg EB and TAI performed 54-56 h after cloprostenol injection. A pregnancy diagnosis was done by ultrasound scanning 40 days after TAI, and the number of fetuses and calves was recorded at pregnancy diagnosis and at birth. More cows treated with eCG displayed estrus within 48 h after removal of the PD (42.3% vs. 11.6%, P < 0.01), and ovulated more than one follicle (42%, 58/138 vs. 1.8%, 1/54; P < 0.01). This effect on ovulation rate was dose dependent (P < 0.05). The pregnancy rate was affected only by cow parity (primiparous, 25.3% vs. multiparous, 48.9%; P < 0.01). Twin pregnancy was higher (P < 0.01) in cows treated with eCG (42%, 58/138) than controls (0%, 0/54). However, few cows (33.3%) were able to keep both fetuses intact until birth. For evaluation of ovarian characteristics by B-mode and Doppler ultrasonography, 43 Nelore cows were submitted In Experiment 2 to the same four groups described in Experiment 1. Although no difference (P > 0.1) was observed for size and blood perfusion in the pre-ovulatory follicles, corpus luteum was larger and with greater blood perfusion (P < 0.05) in eCG-treated cows. In conclusion, eCG increased the number of double/multiple ovulations in a dose-dependent manner, induced larger and more vascularized corpora lutea, but did not affect the fertility of cyclic or anestrous cows. Although eCG results in twin pregnancies, most of cows underwet embryo/fetus loss and birth a single calf.

Superselective microcoil embolization of the vasa recta of sigmoid artery for hemorrhaging after laparoscopic adnexectomy for corpus luteum hematoma with severe adhesion.

A 44-year-old multipara woman was referred because of the sudden onset of left lower abdominal pain. Corpus luteum hematoma was suspected and conservatively managed. Two days later, due to worsening of abdominal symptoms, emergency laparoscopic surgery was performed. Severe pelvic adhesion around the left ovary forming corpus luteum hematoma was identified. After adhesiolysis, which was complicated by massive bleeding, left adnexectomy was performed. Hemostasis was achieved by the coagulation of bleeding vessels, followed by spraying fibrin glue with the placement of oxidized cellulose cotton for bleeding oozing from dissected surface. Two hours after surgery, emergency computed tomography performed due to the development of hemodynamic instability demonstrated extravasation from the versa recta of the sigmoid artery. After the confirmation of hemorrhaging, superselective catheterization to the bleeding vessel followed by embolization by platinum microcoils were performed. Hemodynamic stability was immediately achieved, and the postoperative course was uneventful without manifestation of bowel ischemia.

Hepatic steroid inactivating enzymes, hepatic portal blood flow and corpus luteum blood perfusion in cattle.

Production from the corpus luteum (CL) and/or hepatic steroid inactivation impacts peripheral concentrations of P4, which can alter reproductive performance. Our primary objective was to examine hepatic steroid inactivating enzymes, portal blood flow, and luteal blood perfusion at 10 days post-insemination in pregnant versus non-pregnant beef and dairy cows. Twenty early lactation Holstein cows and 20 lactating commercial beef cows were utilized for this study. At day 10 post-insemination, hepatic portal blood flow and CL blood perfusion were measured via Doppler ultrasonography. Liver biopsies were collected and frozen for later determination of cytochrome P450 1A (CYP1A), 2C (CYP2C), 3A (CYP3A), uridine diphosphate-glucuronosyltransferase (UGT) and aldo-keto reductase 1C (AKR1C) activities. Pregnancy was determined at day 30 post-insemination and treatment groups were retrospectively assigned as pregnant or non-pregnant. Data were analyzed using the mixed procedure of SAS. Steroid metabolizing enzyme activity was not different (p > .10) between pregnant versus non-pregnant beef or dairy cows. Hepatic portal blood flow tended (p < .10) to be increased in pregnant versus non-pregnant dairy cows. Luteal blood perfusion was increased (p < .05) in pregnant versus non-pregnant dairy cows. Pregnant dairy cows appear to have an increased rate of hepatic clearance of P4 in combination with increased synthesis from the CL. This could account for the lack of difference in peripheral P4 concentrations between pregnant and non-pregnant dairy cows. This study highlights the relevance of further investigation into steroid secretion and inactivation and their impact on the maintenance of pregnancy in cattle.

Luteolysis and the Auto-, Paracrine Role of Cytokines From Tumor Necrosis Factor α and Transforming Growth Factor ß Superfamilies.

Successful pregnancy establishment demands optimal luteal function in mammals. Nonetheless, regression of the corpus luteum (CL) is absolutely necessary for normal female cyclicity. This dichotomy relies on intricate molecular signals and rapidly activated biological responses, such as angiogenesis, extracellular matrix (ECM) remodeling, or programmed cell death. The CL establishment and growth after ovulation depend not only on the luteinizing hormone-mediated endocrine signal but also on a number of auto-, paracrine interactions promoted by cytokines and growth factors like fibroblast growth factor 2, vascular endothelial growth factor A, and tumor necrosis factor α (TNF), which coordinate vascularigenesis and ECM reorganization as well as steroidogenesis. With the organ fully developed, the release of the uterine prostaglandin F2α activates luteolysis, an intricate process supported by intraluteal interactions that ensure the loss of steroidogenic function (functional luteolysis) and the involution of the organ (structural luteolysis). This chapter provides an overview of the local action of cytokines during luteal function, with particular emphasis on the role of TNF and transforming growth factor ß superfamilies during luteolysis.