Effect of exogenous oestrogen treatment frequency on induction of artificial lactation in pseudopregnant sows.

In this study, we examined whether the frequency of exogenous oestrogen treatment affects the induction of artificial lactation and milk production. Furthermore, we analysed changes in milk components obtained from artificially lactating sows. Pseudopregnant induced by treatment with 30 mg of estradiol dipropionate (EDP) on Day 10 (Day 0 = the last day of estrus) were divided into three groups: those administered 5 mg of EDP once on Day 39 (n = 5), twice on Days 32 and 39 (n = 5) and three times on Days 25, 32 and 39 (n = 6). All animals were treated with prostaglandin F2α (PGF2α) on Day 46 for induced lactation. Artificial lactation was induced in 66.7%-80.0% of sows, and the EDP treatment frequency before PGF2α administration had no significant effect on either the induction rate of artificial lactation or the milk yield during the experimental period. The milk composition (levels of crude protein, crude fat, crude ash, lactose and immunoglobulin) did not differ among the groups. In conclusion, the number of EDP treatments prior to PGF2α administration had no effect on either the efficiency of artificial lactation induction or milk production.

Effect of prostaglandin alone and in combination with trace minerals on the follicular and luteal dynamics, estrus response and pregnancy in sub-estrus buffaloes (Bubalus bubalis).

Sub-estrus is a condition when buffaloes do not display behavioural estrus signs, despite being in estrus and causes a delay in conception and increases the service period. The present study describes the effect of synthetic prostaglandin (PGF2α) alone and in combination with trace minerals on the follicular and corpus luteum (CL) dynamics, serum estradiol (E2) and progesterone (P4) concentration correlating estrus response and pregnancy outcome in sub-estrus buffaloes during the breeding season. A total of 50 sub-estrus buffaloes, identified through ultrasonography (USG) examination, were randomly allocated into three groups, viz. T1 (Synthetic PGF2α, Inj. Cloprostenol 500 µg, i.m, n = 17), T2 (Synthetic PGF2α + Trace mineral supplementation, Inj. Stimvet 1 mL/100 kg body weight, i.m., n = 17) and control (untreated; n = 16). Following treatment, 100% of sub-estrus buffaloes were induced estrus in the T1 and T2 groups, while only 18.75% were induced in the control. The CL diameter and serum P4 concentration were significantly lower at post-treatment, whereas the pre-ovulatory follicle (POF) size and serum E2 concentration were significantly higher in the T1 and T2 groups as compared to the control (p < .05). The buffaloes of the T2 group had a greater proportion of moderate intensities estrus than those of T1. Moreover, the proportion of buffaloes conceived in the T1 and T2 were 41.2% and 52.95%, respectively. The larger POF diameter and higher serum E2 concentration were associated with intense intensity estrus and higher conception rate (66.7%) in sub-estrus buffaloes. Similarly, CL regression rate, POF size and serum E2 concentration were relatively higher in the buffaloes conceived as compared to those not conceived. It is concluded that synthetic PGF2α in combination with trace minerals induces moderate to intense intensities estrus in a greater proportion of sub-estrus buffaloes and increases the conception rate during the breeding season. Moreover, behavioural estrus attributes correlating follicle and luteal morphometry, serum E2 and P4 concentration could be used to optimise the breeding time for augmenting the conception rate in sub-estrus buffaloes.

De novo reconstruction of a functional in vivo-like equine endometrium using collagen-based tissue engineering.

To better understand molecular aspects of equine endometrial function, there is a need for advanced in vitro culture systems that more closely imitate the intricate 3-dimensional (3D) in vivo endometrial structure than current techniques. However, development of a 3D in vitro model of this complex tissue is challenging. This study aimed to develop an in vitro 3D endometrial tissue (3D-ET) with an epithelial cell phenotype optimized by treatment with a Rho-associated protein kinase (ROCK) inhibitor. Equine endometrial epithelial (eECs) and mesenchymal stromal (eMSCs) cells were isolated separately, and eECs cultured in various concentrations of Rock inhibitor (0, 5, 10 µmol) in epithelial medium (EC-medium) containing 10% knock-out serum replacement (KSR). The optimal concentration of Rock inhibitor for enhancing eEC proliferation and viability was 10 µM. However, 10 µM Rock inhibitor in the 10% KSR EC-medium was able to maintain mucin1 (Muc1) gene expression for only a short period. In contrast, fetal bovine serum (FBS) was able to maintain Muc1 gene expression for longer culture durations. An in vitro 3D-ET was successfully constructed using a collagen-based scaffold to support the eECs and eMSCs. The 3D-ET closely mimicked in vivo endometrium by displaying gland-like eEC-derived structures positive for the endometrial gland marker, Fork headbox A2 (FOXA2), and by mimicking the 3D morphology of the stromal compartment. In addition, the 3D-ET expressed the secretory protein MUC1 on its glandular epithelial surface and responded to LPS challenge by upregulating the expression of the interleukin-6 (IL6) and prostaglandin F synthase (PGFS) genes (P < 0.01), along with an increase in their secretory products, IL-6 (P < 0.01) and prostaglandin F2alpha (PGF2α) (P < 0.001) respectively. In the future, this culture system can be used to study both normal physiology and pathological processes of the equine endometrium.

Ge-gen decoction alleviates primary dysmenorrhoea symptoms in a rat model.

BACKGROUND: Existing treatments for primary dysmenorrhoea (PD), such as NSAIDs, impart side effects. Ge-Gen decoction (GGD), a traditional Chinese medicine, has shown promise in treating PD, but its exact mechanisms remain unclear. Here, we aimed to investigate the efficiency of GGD in alleviating PD using a rat model to understand its precise mechanism of action. METHODS: We established a rat model of dysmenorrhoea induced by oestradiol and oxytocin. The PD rats were administered GGD or Ibuprofen (positive control) intragastrically once daily for seven consecutive days. Serum levels of prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2α), ß-endorphin (ß-EP), thromboxane B2 (TXB2), 6-keto-prostaglandin F1α (6-keto-PGF1α) were determined using an enzyme-linked immunosorbent assay (ELISA). The expression levels of oestrogen receptor alpha (ERα) and cyclooxygenase-2 (COX-2) in uterine tissue were measured using immunohistochemical assays, and those of phosphorylated and total extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) were assessed using western blot analysis. RESULTS: Treatment with GGD significantly reduced writhing behaviour, histopathological scores, and levels of COX-2, PGE2, and PGF2α in the serum of PD rats. Additionally, GGD increased ß-EP content and inhibited ERK1/2 activation and ERα expression in uterine tissues. CONCLUSIONS: The results of this study suggest that GGD alleviates PD in rats by suppressing the COX-2-mediated release of PGE2 and PGF2α, modulating the ERα/ERK1/2/COX-2 pathway, and increasing ß-EP content. These results provide insights into the potential mechanisms of GGD in treating PD and support its further investigation as an alternative therapy for this condition.

Ge-Gen decoction is commonly used to alleviate primary dysmenorrhoea. However, its anti-dysmenorrhoea mechanism remains elusive. In this study, using a rat model of primary dysmenorrhoea, we demonstrate that Ge-Gen decoction reduced the levels of cyclooxygenase-2, prostaglandin E2, and prostaglandin F2 alpha in serum and phosphorylated extracellular signal-regulated protein kinases 1 and 2 in the uterus. These results suggest that Ge-Gen decoction alleviates primary dysmenorrhoea via inactivation of the oestrogen receptor alpha/extracellular signal-regulated protein kinases 1 and 2/cyclooxygenase-2 pathway. This study enhances our understanding of the pathogenesis of primary dysmenorrhoea and may potentially inform the development of novel treatment approaches.

Deciphering feedback regulation of prostaglandin F2α in blood stasis syndrome using nitrogen-doped porous transition metal carbides.

Blood stasis syndrome (BSS) has persistent health risks; however, its pathogenesis remains elusive. This obscurity may result in missed opportunities for early intervention, increased susceptibility to chronic diseases, and reduced accuracy and efficacy of treatments. Metabolomics, employing the matrix-assisted laser desorption/ionization (MALDI) strategy, presents distinct advantages in biomarker discovery and unraveling molecular mechanisms. Nonetheless, the challenge is to develop efficient matrices for high-sensitivity and high-throughput analysis of diverse potential biomarkers in complex biosamples. This work utilized nitrogen-doped porous transition metal carbides and nitrides (NP-MXene) as a MALDI matrix to delve into the molecular mechanisms underlying BSS pathogenesis. Structural optimization yielded heightened peak sensitivity (by 1.49-fold) and increased peak numbers (by 1.16-fold) in clinical biosamples. Validation with animal models and clinical serum biosamples revealed significant differences in metabolic fingerprints between BSS and control groups, achieving an overall diagnostic efficacy of 0.905 (95% CI, 0.76-0.979). Prostaglandin F2α was identified as a potential biomarker (diagnostics efficiency of 0.711, specificity = 0.7, sensitivity = 0.6), and pathway enrichment analysis disclosed disruptions in arachidonic acid metabolism in BSS. This innovative approach not only advances comprehension of BSS pathogenesis, but also provides valuable insights for personalized treatment and diagnostic precision.

Cellular senescence mediates hexavalent chromium-associated lung function decline: Insights from a structural equation Model.

There is sufficient evidence suggesting that exposure to hexavalent chromium [Cr(VI)] can cause a decline in lung function and the onset of lung diseases. However, no studies have yet explored the underlying mechanisms of these effects from various perspectives such as systemic inflammation, oxidative stress, and cellular senescence, simultaneously. This cross-sectional study was conducted among 304 workers engaged in chromate production and processing in China. Urine was used for detection of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-iso-prostaglandin F2α (8-iso-PGF2α), while RNA and DNA extraction from peripheral blood cells was used for detection of mRNA, telomere length, and ribosomal DNA copy numbers (rDNA CNs). A 2.7-fold elevation in blood chromate (Cr) corresponded to a 7.86% (95% CI: 2.57%, 13.42%) rise in urinary 8-OHdG and a 4.14% (0.02%, 8.42%) increase in urinary 8-iso-PGF2α, indicating that exposure to chromates can cause oxidative stress. Furthermore, strong correlations emerged between blood Cr concentration and mRNA levels of P16, P21, TP53, and P15 in the cellular senescence pathway. Simultaneously, a 2.7-fold elevation in blood Cr associated with a -5.47% (-8.72%, -2.1%) change in telomere length, while rDNA CNs (5S, 5.8S, 18S, and 28S) changed by -3.91% (-7.99%, 0.34%), -9.4% (-15.73%, -2.6%), -8.06% (-14.01%, -1.69%), and -5.86% (-10.67%, -0.78%), respectively. Structural equation model highlighted that cellular senescence exerted significant indirect effects on Cr(VI)-associated lung function decline, with a mediation proportion of 23.3%. This study provided data supporting for 8-iso-PGF2α, telomere length, and rDNA CNs as novel biomarkers of chromate exposure, emphasizing the significant role of cellular senescence in the mechanism underlying chromate-induced lung function decline.

Estrogens improve the pregnancy rate in cattle: A review and meta-analysis.

Estrogens have proven to be effective in bovine estrus induction protocols. Considering the extensive use of these products in large-scale estrus synchronization, the primary objective of the present study was to assess their effects on pregnancy rate (PR) using a meta-analysis approach. A total of 797 papers were screened from three major databases (PubMed, Web of Science, Scopus). Sixty-one studies were eligible for inclusion in the meta-analysis. The pregnancy status (success or failure) at 30 days post-insemination was considered as the effect size data. The odds ratios (OR) of PR were evaluated by considering the effects of estrogens in groups with or without estrogen intervention. The impact of estrogen (including factors such as type, dose, and time of administration) and animal characteristics (such as breed, type, and parity) was taken into account when assessing the effectiveness of estrogen response as PR. The results showed an OR of 1.25 (95% CI: 1.15-1.36; P = 0.000) for PR in animals that received estrogen compared to cattle that did not receive estrogen. Estradiol benzoate (OR = 1.3) and estradiol cypionate (OR = 1.2), with doses ranging from 1 to 3 mg (OR = 1.13-1.7), significantly increased the OR of PR. In terms of PR, beef cattle exhibited a higher odds ratio (OR = 1.4; P = 0.000) compared to dairy cattle (OR = 1.1; P = 0.09). The administration of estrogens in the estrus synchronization protocol significantly improved PR in both artificial insemination (OR = 1.2; P = 0.000) and embryo transfer (OR = 1.3; P = 0.033) programs. In summary, incorporating estrogens into estrus induction protocols led to an enhancement of the OR of PR among cattle.

Using differential mobility spectrometry to improve the specificity of targeted measurements of 2,3-dinor 11ß-Prostaglandin F2α.

INTRODUCTION: 2,3-dinor 11ß-Prostaglandin F2α (BPG) is an arachidonic acid derivative and the most abundant metabolic byproduct of prostaglandin D2, which is released during mast cell activation. Therefore, measurements of BPG in urine using liquid chromatography-tandem mass spectrometry (LC-MS/MS) provide a noninvasive method for evaluation and management of mast cell disorders. Measurements obtained by LC-MS/MS exhibit a high prevalence of chromatographic interferences resulting in challenges with optimal determination of BGP. In this investigation, differential mobility spectrometry (DMS) is utilized to overcome the limitations of current testing. METHODS: Urine samples were extracted using an automated solid-phase extraction method. Samples were then analyzed with and without DMS devices installed on two commercially available mass spectrometry platforms to assess the benefits of DMS. Following promising results from a preliminary analytical evaluation, LC-DMS-MS/MS measurements of BPG in urine were fully validated to assess the analytical implications of using this technology. RESULTS AND DISCUSSION: The addition of DMS devices to the LC-MS/MS systems evaluated in this investigation significantly reduced interferences observed in the chromatograms. Concomitantly, DMS reduced the number of discordant quantifier/qualifier fragment ion results that significantly exceeded the ± 20 % limits, suggesting greater analytical specificity. The validation studies yielded low interday imprecision, with %CVs less than 6.5 % across 20 replicate measurements. Validation studies assessing other aspects of analytical performance also met acceptance criteria. CONCLUSIONS: Incorporating DMS devices greatly improved the specificity of BPG measurements by LC-MS/MS, as evidenced by the comparison of chromatograms and fragment ion results. Validation studies showed exceptional performance for established analytical metrics, indicating that this technology can be used to minimize the impact of interferences without adversely impacting other aspects of analytical or clinical performance.

Magnitude and persistence of higher estrus-associated temperatures in beef heifers and suckled cows.

Higher estrus-associated temperatures (HEAT) are a hallmark feature in sexually active females. The overarching aim of this study was to characterize the variability, magnitude, and persistence of HEAT in heifers and suckled beef cows as well as identify associated factors when occurring during thermoneutral conditions at the onset of the spring breeding season. In both heifers and cows, estrus was induced using a 7-d controlled internal drug release (CIDR)-PGF2α protocol. Vaginal temperature after prostaglandin F2α administration was recorded every 5 min using a Thermochron iButton affixed to a blank CIDR (containing no progesterone). Estrus was defined as when a heifer first stood to be mounted or when a cow had an Estrotect patch score of 3 or 4. Level of HEAT varied among individual animals. When comparing common HEAT variables using a mixed model with date nested within a year, maximum HEAT (39.9 ±â€…0.1 and 40.0 ±â€…0.1 °C) and duration (15.5 ±â€…0.8 and 15.4 ±â€…0.7) were similar in heifers and cows, respectively. However, the magnitude and persistence of HEAT differed. Total area under the HEAT curve was 117.1 ±â€…13.5 and 158.7 ±â€…12.3 for heifers vs cows, respectively (P = 0.0571). Further, 42.9% of heifers and 49% of cows had maximum HEAT ≥ 40 °C which persisted up to 6.5 and 10 h, respectively. When ambient conditions were predominantly thermoneutral, temperature humidity index had minimal impact on HEAT (mixed model, repeated measures over time). Toward identifying associated factors with different aspects of HEAT using best fit hierarchical linear regression models, baseline vaginal temperature and baseline duration were the most highly associated independent variables. Follicle size, estradiol and progesterone levels, and other available animal-related variables (e.g., age, weight, hair coat score) explained only a small amount of variation in HEAT. In summary, level of HEAT varies in estrus females even under thermoneutral conditions. Because HEAT can persist for an extended time, direct effects on fertility important components are unavoidable. Whether HEAT is a good or bad component of the periovulatory microenvironment is the basis of ongoing and future studies.

When striving for a pregnancy, estrus is a critically important event. Higher estrus-associated temperatures (HEAT) are a hallmark feature in sexually active females. The importance of HEAT for pregnancy, however, remains unclear. Toward filling this critical knowledge gap, efforts described in the current study focused on examining variability of HEAT in individual animals, 2) defining the magnitude and persistence of HEAT, 3) identifying HEAT-associated factors, and 4) examining the similarity of HEAT between heifers and suckled beef cows when occurring at the onset of a spring breeding season. Although the magnitude and persistence of HEAT varied, 42.9% of heifers and 49% of cows reached temperatures ≥ 40 °C which in some cases persisted up to 6.5 and 10 h, respectively. When attempting to identify factors that could explain why some females exhibiting estrus remained hot for an extended time, available animal and environmental data contributed little. Even so, because HEAT can persist for an extended time, direct effects on fertility important components are unavoidable. Whether too much HEAT is good or bad for pregnancy is the basis of ongoing and future studies.

The influence of physical activity, body mass index and urinary levels of prostaglandin (PGF2α) with the incidence of primary dysmenorrhea in adolescents.

OBJECTIVE: This study aims to investigate the effect of physical activity, body mass index (BMI), and levels of prostaglandins (PGF2α) urine on the occurrence of dysmenorrhea in adolescents. METHODS: A total of 128 female students included in the study. The study was conducted from January to March 2023 using a cross-sectional design. This study utilized the Menstrual Symptom Questionnaire (MSQ) and gynecological examination with ultrasonography. The urinary prostaglandin (PGF2α) was measured using the enzyme linked immuno sorbent assay (ELISA). Data were analyzed using the chi-square test and logistic regression test. RESULTS: The age range of the participants included in the study was 14-17, with a mean age of 15.85 ± 0.65. There was an correlation between physical activity, BMI, and urinary prostaglandin (PGF2α) levels with the incidence of dysmenorrhea in adolescents (p < 0.001). In multivariate analysis, it revealed that underweight, and had a high urinary prostaglandin significant correlated to primary dysmenorrhea with odds ratio 4.78 (95% confidence interval [CI] 1.98-11.54) and 4.88 (95% CI 1.98-12.08), respectively. High physical activity and overweight was not associated with incidence of dysmenorrhea in adolescents. CONCLUSION: This study provides valuable insights into the correlation between physical activity, BMI, and levels of prostaglandins (PGF2α) in urine. A high level of urinary prostaglandin was found to be the most influential factor in the incidence of primary dysmenorrhea in adolescents. By addressing factors associated with dysmenorrhea in adolescents, healthcare professionals can potentially enhance well-being by reducing menstrual pain and encouraging a healthy lifestyle to prevent dysmenorrhea.

Effect of photobiomodulation on alleviating primary dysmenorrhea caused by PGF2α.

Photobiomodulation (PBM) has attracted widespread attention in suppressing various pain and inflammation. Primary dysmenorrhea (PD) primarily occurs in adolescents and adult females, and the limited effectiveness and side effects of conventional treatments have highlighted the urgent need to develop and identify new adjunct therapeutic strategies. In this work, the results of pain and PGs demonstrated that 850 nm, 630 nm, and 460 nm all exhibited pain inhibition, decreased PGF2α and upregulated PGE2, while 630 nm PBM has better effectiveness. Then to explore the underlying biological mechanisms of red light PBM on PD, we irradiated prostaglandin-F2α induced HUSM cells and found that low-level irradiance can restore intracellular calcium ion, ROS, ATP, and MMP levels to normal levels. And, red light enhanced cell viability and promoted cell proliferation for normal HUSM cells. Therefore, this study proposes that red light PBM may be a promising approach for the future clinical treatment of PD.

Effects of equine chorionic gonadotropin dosage and its splitting in different days on reproductive performance of Nellore cows synchronized for timed-artificial insemination.

This study evaluated the effects of dose of equine chorionic gonadotropin (eCG) and its splitting in different days of the synchronization protocol on reproductive performance of primiparous and multiparous Nellore cows. In the present study, 2,536 Nellore cows (1,634 primiparous and 902 multiparous) were assigned to receive in a 2 × 2 factorial design 1) an intravaginal progesterone (P4) device and 2.0 mg of estradiol benzoate (EB) on day -11, 12.5 mg (i.m.) of dinoprost tromethamine (PGF), 300 IU (i.m.) of eCG, 0.6 mg (i.m.) of estradiol cypionate (ECP), and P4 device withdrawal on day -2, followed by TAI on day 0 (n = 632 cows, being 409 primiparous and 223 multiparous; 300-2), 2) 300 IU (i.m) of eCG administered on days -4 and -2 (150 IU of eCG/day; n = 637 cows, being 412 primiparous and 225 multiparous; 300-4-2), 3) 400 IU (i.m.) of eCG administered on day -2 (n = 633 cows, being 406 primiparous and 227 multiparous; 400-2), and 4) 400 IU (i.m) of eCG administered on days -4 and -2 (200 IU of eCG/day; n = 634 cows, being 407 primiparous and 227 multiparous; 400-4-2). Individual cow BCS was assessed on days -11, 0 (timed-AI), and 31 of the study. Body condition score of the animals was classified into LOW or HIGH using the threshold of 2.75 (≤2.75 = LOW; >2.75 = HIGH). For primiparous cows, an eCG splitting effect was observed on follicle size, as cows receiving eCG on days -4 and -2 of the synchronization protocol had a larger follicle than cows administered eCG only on day -2. For day 31 P/AI, primiparous cows receiving 400-4-2, regardless of BCS, had a greater P/AI than cows from other treatments. Administering 400-4-2 to LOW BCS cows also resulted in greater P/AI than all other treatments assigned to LOW BCS cows. For multiparous cows, no treatment effect was observed for follicle size, estrus expression, and day 31 P/AI (P ≥ 0.21). In summary, increasing the dose and splitting the dose of eCG positively impacted the pregnancy rates of primiparous cows under a BCS ≤2.75, but no effects were detected on multiparous cows.

Prostaglandin F2α Affects the Cycle of Clock Gene Expression and Mouse Behavior.

Prostaglandins are bioactive compounds, and the activation of their receptors affects the expression of clock genes. However, the prostaglandin F receptor (Ptgfr) has no known relationship with biological rhythms. Here, we first measured the locomotor period lengths of Ptgfr-KO (B6.129-Ptgfrtm1Sna) mice and found that they were longer under constant dark conditions (DD) than those of wild-type (C57BL/6J) mice. We then investigated the clock gene patterns within the suprachiasmatic nucleus in Ptgfr-KO mice under DD and observed a decrease in the expression of the clock gene cryptochrome 1 (Cry1), which is related to the circadian cycle. Moreover, the expression of Cry1, Cry2, and Period2 (Per2) mRNA were significantly altered in the mouse liver in Ptgfr-KO mice under DD. In the wild-type mouse, the plasma prostaglandin F2α (PGF2α) levels showed a circadian rhythm under a 12 h cycle of light-dark conditions. In addition, in vitro experiments showed that the addition of PTGFR agonists altered the amplitude of Per2::luc activity, and this alteration differed with the timing of the agonist addition. These results lead us to hypothesize that the plasma rhythm of PGF2α is important for driving clock genes, thus suggesting the involvement of PGF2α- and Ptgfr-targeting drugs in the biological clock cycle.

The fertility of dairy heifers and cows is not influenced by the follicular wave of the ovulatory follicle.

Two studies were conducted to evaluate the effects of the follicular wave on ovarian function and fertility in dairy heifers and lactating cows. In study 1, the estrous cycle of the selected Holstein heifers was initially synchronized using two intra-muscular prostaglandin F2α (PGF2α) administrations 11 days apart. Heifers in group FFW (n = 14) received an intra-muscular 500 µg PGF2α administration on day 7 after detecting standing estrus, while Heifers in group SFW (n = 14) were administered PGF2α 13 days after detecting standing estrus. The pregnancy rates of FFW (n = 98) and SFW (n = 100) heifers were also determined 35-37 days after artificial insemination (AI). In Study 2, healthy Holstein lactating cows (n = 28) were randomly assigned to either the FFW (n = 14) or SFW (n = 14) groups. The estrous cycles of the cows were presynchronized using two intra-muscular administrations of PGF2α given 14 days apart. Then, the emergences of the follicular waves were induced using an Ovsynch protocol. The pregnancy rate of FFW (n = 99) versus SFW (n = 98) cows was also determined 35-37 days after AI. The ovulatory follicle and corpus luteum (CL) resulting from the ovulatory follicle of FFW were larger than those of the dominant follicle and the CL of SFW in dairy heifers and lactating cows. However, the pregnancy rate did not differ between the FFW and SFW groups in heifers and lactating cows 35-37 days after AI. In conclusion, although the characteristics of the ovulatory follicles in FFW versus SFW animals differed, the follicular wave in dairy heifers or lactating cows did not affect fertility.

Equine chorionic gonadotropin treatment and timed artificial insemination for dairy cow production under heat stress.

This study investigated the effects of timed artificial insemination (TAI) and equine chorionic gonadotropin (eCG) administration on lactating dairy cows under heat-stress conditions (average temperature-humidity index: 80). Timed artificial insemination was performed on the cows with (n = 57) or without (control, n = 41) supplementation with 500 IU of eCG at the day of PGF2α treatment using the CIDR-Ovsynch protocol. GnRH was administered, and a progesterone device (CIDR) was inserted on Day -10 of the treatment protocol. The CIDR was removed on Day -3, and the cows were treated with PGF2α. Two days later, a 2nd GnRH injection was administered. Subsequently, AI was performed on Day 0 (16-20 h after the 2nd GnRH injection), and pregnancy was diagnosed on Days 32 and 60. Plasma progesterone (P4) concentrations were measured after AI. Results showed that the eCG group had a higher pregnancy per AI (P/AI) than the control group (43.9 vs. 12.2%, P = 0.002), which was also accompanied by elevated P4 levels. Four cows in the eCG group had multiple calves, representing 7.0 and 16.0% of the group and pregnant cows, respectively. In conclusion, 500 IU of eCG combined with CIDR-Ovsynch in lactating dairy cows under severe heat stress conditions successfully improved fertility. However, the protocol may have a slight risk of multiple births.

Phenanthroline relaxes uterine contractions induced by diverse contractile agents by decreasing cytosolic calcium concentration.

Uterine contractions during labor and preterm labor are influenced by a complex interplay of factors, including hormones and inflammatory mediators. This complexity may contribute to the limited efficacy of current tocolytics for preterm labor, a significant challenge in obstetrics with 15 million cases annually and approximately 1 million resulting deaths worldwide. We have previously shown that the myometrium expresses bitter taste receptors (TAS2Rs) and that their activation leads to uterine relaxation. Here, we investigated whether the selective TAS2R5 agonist phenanthroline can induce relaxation across a spectrum of human uterine contractions and whether the underlying mechanism involves changes in intracellular Ca2+ signaling. We performed experiments using samples from pregnant women undergoing scheduled cesarean delivery, assessing responses to various inflammatory mediators and oxytocin with and without phenanthroline. Our results showed that phenanthroline concentration-dependently inhibited contractions induced by PGF2α, U46619, 5-HT, endothelin-1 and oxytocin. Furthermore, in hTERT-infected human myometrial cells exposed to uterotonics, phenanthroline effectively suppressed the increase in intracellular Ca2+ concentration induced by PGF2α, U46619, oxytocin, and endothelin-1. These results suggest that the selective TAS2R5 agonist may not only significantly reduce uterine contractions but also decrease intracellular Ca2+ levels. This study highlights the potential development of TAS2R5 agonists as a new class of uterine relaxants, providing a novel avenue for improving the management of preterm labor.

Uteroovarian pathway for embryo-empowered maintenance of the corpus luteum in farm animals.

The first luteal response to pregnancy in farm animals at 12-18 days after ovulation involves maintenance of the corpus luteum (CL) if pregnancy has occurred. In most common farm species, regression of the CL results from production of a luteolysin (PGF2α) by the nongravid uterus, and maintenance of the CL involves the production of an antiluteolysin (PGE2) by the gravid uterus and conceptus. The proximal component of a unilateral pathway from a uterine horn to the adjacent CL for transport of PGF2α and PGE2 is the uterine venous and lymphatic vessels and the distal component is the ovarian artery. The mechanisms for venolymphatic arterial transport of PGF2α and PGE2 from a uterine horn to the adjacent CL ovary and transfer of each prostaglandin through the walls of the uteroovarian vein and ovarian artery occur by similar mechanisms probably as a consequence of similarities in molecular structure between the two prostaglandins. Reported conclusions or interpretations during the first luteal response to pregnancy in sows and ewes are that PGE2 increases in concentration in the uteroovarian vein and ovarian artery and counteracts the negative effect of PGF2α on the CL. In cows, treatment with PGE2 increases circulating progesterone concentrations and prevents spontaneous luteolysis and luteolysis induced by estradiol, an intrauterine device, or PGF2α. The prevailing acceptance that interferon tau is the primary factor for maintaining the CL during early pregnancy in ruminants will likely become tempered by the increasing reports on PGE2.

A century of research on the uteroovarian pathway for uterine-induced luteolysis in mammals.

Year 2023 is the 100-year anniversary of the discovery in guinea pigs that the lifespan of the corpus luteum (CL) is controlled by the uterus. The CL is the gatekeeper between two fundamental reproductive events - the estrous cycle and pregnancy. Uteroluteal research for the initial 33 years was productive but limited to laboratory species until the inclusion of farm animals in 1956. In the early 1960s, it was found that uterine luteolysin in sows travels unilaterally from a uterine horn to the adjacent CL which likely accounted for the heyday of uteroluteal research in the 1960s-70s. The luteolytic properties of PGF2α were demonstrated in rats in 1969. In 1971, (1) surgical separation of the lengthwise adherence between the uteroovarian vein and ovarian artery interfered with luteolysis in ewes, (2) species with primarily unilateral vs systemic uterine-induced luteolysis have a strong vs an absent or weak unilateral venoarterial transfer pathway, and (3) vascular infusions identified PGF2α as a uterine luteolysin. Vascular and PGF2α studies were beginning to merge. In 1973, a venoarterial pathway was firmly demonstrated in ewes and later in heifers by surgical anastomosis of a uterine vein or ovarian artery from a uterine-intact side to the corresponding vessel on the unilaterally hysterectomized side. More recent studies described how prostaglandins likely transfer through the walls of uterine and ovarian vessels using concentration gradients in sows and a prostaglandins transporter system in cows.

GnRH analogs induce a LH peak and increase pregnancy per timed-AI in ewes.

To date, there have been no studies testing the capacity of GnRH analogs and respective doses to induce a LH peak in sheep. In this sense, the present study aimed to evaluate the capacity of different synthetic forms and doses of GnRH in inducing LH release in sheep, and the effect of GnRH administration at timed artificial insemination (TAI) on pregnancy per timed-AI. In experiment 1, ewes (n = 40) received an intravaginal device (IVD) of medroxyprogesterone acetate (MPA; 60 mg) for 7 d and prostaglandin F2α analog on Day 5. On Day 7, the ewes were allocated randomly into one of eight groups (n = 5/group), which received a GnRH analog at a specific dose, as follows: lecirelin (12.5 or 25 µg), gonadorelin (50 or 100 µg), buserelin acetate (4.2 or 8.4 µg), or deslorelin (375 or 750 µg). Blood samples for LH determination were obtained at 0, 2, 4, and 6 h after GnRH and the IVDs were removed after the last blood collection. The maximal LH concentration induced by gonadorelin at doses of 50 µg and 100 µg (12.0 ± 2.4 ng/mL and 28.6 ± 7.1 ng/mL, respectively) was lower (P < 0.05) than serum LH induced by 8.4 µg of buserelin (78.9 ± 12.9 ng/mL), 375 µg and 750 µg of deslorelin (75.6 ± 7.4 ng/mL and 72.1 ± 10.6 ng/mL, respectively) and 12.5 µg and 25 µg of lecirelin (73.3 ± 17.8 ng/mL and 61.6 ± 5.9 ng/mL, respectively). However, the maximal LH concentration induced by 4.2 µg of buserelin (49.4 ± 5.9 ng/mL) was similar (P > 0.05) to the 100 µg of gonadorelin. The total release of LH (area under the curve - AUC) after treatment with 50 µg of gonadorelin (31.7 ± 5.9 ng h/mL) was lower (P < 0.05) than after other agonists. In a second experiment, 330 ewes were treated with IVD containing MPA for 7 d. Simultaneously with IVD removal, 250 µg of cloprostenol and 200 IU of eCG were administered. Then, ewes were assigned randomly to either no further treatment (control); or to receive 4.2 µg of buserelin acetate (GnRH group) at cervical TAI, which was performed with fresh semen 54 h after IVD withdrawal in all the animals. Higher pregnancy per timed-AI was observed for GnRH (50.3 %) compared to control (40.7 %). We conclude that buserelin acetate (8.4 µg), lecirelin (12.5 and 25 µg) and deslorelin (375 and 750 µg) induced a greater stimulatory effect on LH secretion than gonadorelin treatment. Furthermore, buserelin acetate treatment at TAI increased pregnancy per timed-AI in ewes previously treated with MPA and eCG.

Myeloid Bmal1 deletion suppresses the house dust mite-induced chronic lung allergy.

Asthma is the chronic pulmonary inflammatory response that could lead to respiratory failure when allergic reactions exacerbate. It is featured by type 2 immunity with eosinophilic inflammation, mucus, and IgE production, and Th2 cytokine secretion upon repeated challenge of allergens. The symptom severity of asthma displays an apparent circadian rhythm with aggravated airway resistance in the early morning in patients. Bmal1 is the core regulator of the circadian clock, while the regulatory role of Bmal1 in asthma remains unclear. Here, we investigate whether the myeloid Bmal1 is involved in the pathogenesis of house dust mite (HDM)-induced lung allergy. We found that knockdown of Bmal1 in macrophages suppressed the time-of-day variance of the eosinophil infiltration in the alveolar spaces in chronic asthmatic mice. This was accompanied by decreased bronchial mucus production, collagen deposition, and HDM-specific IgE production. However, the suppression effects of myeloid Bmal1 deletion did not alter the allergic responses in short-term exposure to HDM. The transcriptome profile of alveolar macrophages (AMs) showed that Bmal1-deficient AMs have enhanced phagocytosis and reduced production of allergy-mediating prostanoids thromboxane A2 and prostaglandin F2α synthesis. The attenuated thromboxane A2 and prostaglandin F2α may lead to less induction of the eosinophil chemokine Ccl11 expression in bronchial epithelial cells. In summary, our study demonstrates that Bmal1 ablation in macrophages attenuates eosinophilic inflammation in HDM-induced chronic lung allergy, which involves enhanced phagocytosis and reduced prostanoid secretion.