PGF2α Metabolite Research Articles

Hormonal profiles and biomarkers leading to parturition in cattle.

This study aimed to understand the physiological mechanisms regulating parturition and to identify potential biomarkers to predict onset of birth. Additionally, we compared hormone profiles between cows with shorter and longer gestation lengths. Twenty-eight days before due date until 3d postpartum, cows (n = 18) were blood sampled daily. Circulating concentrations were measured for progesterone (P4) and estradiol (E2) by RIA, testosterone, prostaglandin F2α metabolite (PGFM), cortisol, pregnancy-specific protein B (PSPB) by ELISA and lactate concentrations by colorimetric assay. At end of gestation, P4 decreased from d-14 to d-4 (from 3.6 to 1.4ng/mL), most likely from rapid loss of placental P4 production (64% of decline in 24h). A second rapid decrease in P4 to undetectable concentrations was observed from d-2 to parturition (from 1.4 to 0.1ng/ml; most likely luteal origin) corresponding to increase in PGFM from d-2 to parturition (249.7 to 2868.4pg/mL). Estradiol and PSPB increased ~8-fold from ~13d before parturition with acute rise in E2 but not PSPB (45% vs 13% in first 24h). Testosterone decreased slightly during the same period. Cortisol and lactate increased only at calving. Comparison of cows with shorter vs longer gestation, when data were normalized to parturition day, a difference was detected in circulating E2 and PGFM patterns, but not P4 and PSPB. Thus, the first significant hormonal changes associated with parturition begin at d-14 with E2 and PSPB as two clear biomarkers of impending parturition. Cows with shorter and longer gestation had hormonal differences indicative of identifiable earlier placental maturation.

In mares resistant to endometrial infection, periovulatory treatment with ecbolic drugs does not influence uterine clearance or luteal development

We aimed to determine associations between experimentally impaired uterine clearance or treatment with ecbolic drugs on luteal development in estrous mares after insemination. In a crossover design, eight mares were treated with saline (CON), clenbuterol (CLEN), oxytocin (OXY) and carbetocin (CARB) from the day of first insemination until 2 days after ovulation. Between treatments, the mares rested for one cycle. Estrous mares were examined for the presence of free intrauterine fluid by transrectal ultrasound. Endometrial swabs for cytology and bacteriology were collected on days 1 and 14. Blood samples were collected daily before AI until day 14 after ovulation for determination of progesterone and PGF2α metabolites (PGFM). Differences between treatments were compared by a general linear model for repeated measures (SPSS 29). One mare was excluded because of a uterine infection in the control cycle. In all other mares, only minor amounts of free intrauterine fluid were present after insemination and decreased over time (P<0.05) with no treatment x time interaction. There was no effect of treatment on polymorphonucleated cells (PMN) in endometrial cytology after ovulation or PGFM secretion. Progesterone release from day 1–14 as well as pregnancy rate and conceptus size on day 14 was not influenced by treatment. In conclusion, treatment with clenbuterol does not impair uterine clearance in estrous mares resistant to endometritis. Repeated injection of the oxytocin analogue carbetocin during the early postovulatory period is not detrimental to corpus luteum function and can be recommended to enhance uterine clearance.

Effect of cytobrush technique in mares

Several studies have been done correlating transcervical techniques or mechanical manipulation on the endometrium and its effect on the equine estrous cycle length in mares. However, the effect of the endometrial cytobrush technique on the estrous cycle and its use for the study of endometrial-ovarian relationships is still unknown. The aim of this study was to evaluate the usage of the endometrial cytobrush technique for study of the role of endometrial receptors and genes involved in the luteolytic mechanism. The study was divided in three groups: single endometrial cytobrush (CBS), endometrial samples collected in different animals on days 12, 14, and 16 (n = 5 /day); endometrial samples collect multiple times (CBM) in the same animal on days 12, 14, and 16 (n = 5/day); no endometrial samples collection (CSN). Blood samples were collected daily from ovulation to subsequent ovulation on the three groups to evaluate progesterone (P4) concentration. Additionally, on Day 12, blood samples were collected at h0 (just before cytobrush collection), 15 min, 30 min, h1, h2, and h4 to evaluate concentrations of P4 and a metabolite of prostaglandin F2α (PGFM). The gene expression was compared among the preluteolytic, luteolytic, and postluteolytic periods. The day before P4 concentration decreased by 20% from the previous day with an uninterrupteddecrease thereafter was defined as the beginning of luteolysis (luteolytic period), and the first day P4 concentration decreased to < 1.0 ng/mL was defined as the end of luteolysis (postluteolytic period). The interovulatory length, beginning of luteolysis, and concentrations of P4 and PGFM did not differ among the groups (P > 0.05). Three animals in the CBM group developed 5 ± 2 mm of endometrial fluid after the second cytobrush collection. However, these animals did not have endometrial fluid after ovulation. According to endometrial gene expression, in the CBM group, the prostaglandin-endoperoxide synthase 2 (PTGS2) was upregulated during luteolysis (P < 0.05), PGF transporter (SLCO2A1) was upregulated after luteolysis, and 15-hydroxyprostaglandin dehydrogenase (HPGD) was downregulated during luteolysis. In the CBS group, oxytocin receptor (OXTR), prostaglandin F2 receptor (PTGFS), and (HPGD) were upregulated during luteolysis (P < 0.05). SLCO2A1 was upregulated during and after luteolysis (P < 0.05). These results suggest that endometrial cytobrush technique does not influence the length of the cycle and is a viable method for studying endometrial gene expression of genes associated with luteolysis in a single sample collection in mares.

153 The effect of high or low concentration of progesterone during diestrus and its association with the LH surge and PGF2α metabolite in lactating Holstein cattle

153 The effect of high or low concentration of progesterone during diestrus and its association with the LH surge and PGF2α metabolite in lactating Holstein cattle

150 Indomethacin infusion through multiple routes and the resulting Prostaglandin F2α metabolite production during late embryonic development in beef cattle

150 Indomethacin infusion through multiple routes and the resulting Prostaglandin F2α metabolite production during late embryonic development in beef cattle

Serum concentrations of secretory leukocyte protease inhibitor and IL6 can predict the onset of sepsis in pyometra bitches.

As onset of sepsis adversely affects the prognosis of canine pyometra, finding biomarkers that would distinguish sepsis status would be useful in the clinical management. Accordingly, we hypothesized that differential expression of endometrial transcripts and circulating concentration of certain inflammatory mediators would discriminate pyometra-led sepsis (P-sepsis+) from those of pyometra without sepsis (P-sepsis-). Bitches with pyometra (n = 52) were classified into P-sepsis+ (n = 28) and P-sepsis- (n = 24) based on vital clinical score and total leukocyte count. A group of non-pyometra bitches (n = 12) served as control. The relative fold changes in the transcripts of IL6, IL8, TNFα, IL10, PTGS2, mPGES1 and PGFS, SLPI, S100A8, S100A12 and eNOS were determined by quantitative polymerase chain reaction. Furthermore, the serumconcentrations of IL6, IL8, IL10, SLPI and prostaglandin F2α metabolite (PGFM) were assayed by ELISA. The relative fold changes in S100A12 and SLPI and mean concentrations of IL6 and SLPI were significantly (p < .05) higher in P-sepsis+ than that of P-sepsis- group. Receiver operating characteristic analysis revealed that serum IL6 had a diagnostic sensitivity of 78.6% and a positive likelihood ratio (LR+) of 2.09, at a cut-off value of 15.7 pg/mL to diagnose P-sepsis+ cases. Similarly, serum SLPI had a sensitivity of 84.6% and an LR+ of 2.23, at a cut-off value of 2.0 pg/mL. It was concluded that SLPI and IL6 would serve as putative biomarkers for pyometra-led sepsis in bitches. Monitoring SLPI and IL6would be a useful adjunct to the established haemato-biochemical parameters in customizing the treatment strategies and arriving at the decision for management of pyometra bitcheswith critical illness.

PGF2α facilitates pathological retinal angiogenesis by modulating endothelial FOS-driven ELR+ CXC chemokine expression.

The pathological retinal angiogenesis often causes blindness. Current anti-angiogenic therapy for proliferative retinopathy targets the vascular endothelial growth factor (VEGF), but many patients do not radically benefit from this therapy. Herein, we report that circulating prostaglandin (PG) F2α metabolites were increased in type 2 diabetic patients with proliferative retinopathy, and the PGF2α receptor (Ptgfr) was upregulated in retinal endothelial cells (ECs) from a mouse model of oxygen-induced retinopathy (OIR). Further, disruption of the PTGFR receptor in ECs attenuated OIR in mice. PGF2α promoted the proliferation and tube formation of human retinal microvascular endothelial cells (HRMECs) via the release of ELR+ CXC chemokines, such as CXCL8 and CXCL2. Mechanistically, the PGF2α /PTGFR axis potentiated ELR+ CXC chemokine expression in HRMECs through the Gq /CAMK2G/p38/ELK-1/FOS pathway. Upregulated FOS-mediated ELR+ CXC chemokine expression was observed in retinal ECs from PDR patients. Moreover, treatment with PTGFR inhibitor lessened the development of OIR in mice in a CXCR2-dependent manner. Therefore, inhibition of PTGFR may represent a new avenue for the treatment of retinal neovascularization, particularly in PDR.

Scopolamine administration in repeat breeder cows on the day of heat

Scopolamine is a parasympatholytic drug that can modulate uterine contractile activity. Based on the hypothesis that deficiency in uterine contractility is a cause of Repeat Breeder (RB) syndrome in cows, this study aimed to evaluate the efficacy of scopolamine administration in RB cows, on the day of heat, in increasing conception rates. Forty RB cows were randomly divided into treated group [T; 20 cows treated with scopolamine butylbromide 40 mg/100 kg of body weight (BW) by the intramuscular (IM) route after clinical confirmation of heat (T0)] and the control group [C; 20 cows treated with 2 mL/100 kg of BW of saline solution, IM, at T0]. Twelve hours later (T1), all of the cows were artificially inseminated (AI). Blood plasma-progesterone (P4), hydroxyproline, and prostaglandin F2α metabolite (PGFM), concentrations were assessed at T0 and T1. Additionally, the uterine tone was evaluated by transrectal palpation. Conception rates were recorded. Drug administration increased the conception rates in group T to 80% unlike group C (25%) (P < 0.0001). Higher PGFM concentration levels were registered in the treated group than in the control group. The higher PGF2α secretion in pregnant cows of the T group may have reduced the P4 levels, making conception possible. Scopolamine administration at the time of heat can improve uterine contractility. This makes it more suitable for promoting conception in RB cows, where hormonal alterations and contractile and biochemical deficits are responsible for the syndrome.

Asiatic acid alleviates liver fibrosis via multiple signaling pathways based on integrated network pharmacology and lipidomics

Liver fibrosis is characterized by the abnormal deposition of the extracellular matrix with a severe inflammatory response and/or metabolic disorder. Asiatic acid (AA), a natural compound derived from Centella asiatica, exhibited potent anti-fibrosis effects. This investigation first confirmed the anti-fibrosis effects of AA in TGF-β-LX-2 cells and CCl4-induced liver fibrosis mice, and then sought to elucidate a novel mechanism of action by integrating network pharmacology and lipidomics. Network pharmacology was used to find potential targets of AA, while lipidomics was used to identify differential metabolites between fibrosis and recovered cohorts. AA could suppress hepatic stellate cell activation in vitro and improve liver fibrosis in vivo. Network pharmacology unveiled the genes involved in pathways in cancer, peroxisome proliferators-activated receptors signaling pathway, and arachidonic acid metabolism pathway. Furthermore, five key genes were found in the both human and mouse databases, indicating that arachidonic acid metabolism was important. Changes in lyso-phosphocholine (22:5), prostaglandin F2α, and other related lipid metabolites also suggested the involvement of arachidonic acid metabolism the anti-fibrotic effect. In summary, our integrated strategies demonstrated that AA targeted multiple targets and impeded the progression of liver fibrosis by ameliorating arachidonic acid metabolism.

Use of serum progesterone and prostaglandin F2α metabolite levels to predict onset of parturition in the bitch.

The prediction of time to onset of parturition in a preparturient bitch is of great clinical value, particularly for bitches at high risk of dystocia and those lacking relevant clinical data from the time of breeding. In a previous study, four cut-offs for plasma progesterone levels, measured by radioimmunoassay, were shown to be useful for predicting the likelihood of a bitch entering stage one of parturition within defined time intervals. The first aim of the current study was to evaluate these cut-offs in a clinical setting, using serum progesterone samples drawn from preparturient bitches 12-hourly instead of 6-hourly and assessed using chemiluminescence immunoassay. Furthermore, the use of 13,14-dihydro-15-keto-prostaglandin F2α, (PGFM), a metabolite of prostaglandin F2α , in predicting the time to onset of parturition was evaluated. Forty bitches carrying two or more foetuses were admitted to a specialist veterinary reproduction hospital 53 d after the onset of cytological dioestrus when that date was known, or 57 d after the last mating. Vaginal speculum examinations were performed every 6hr until cervical dilatation was visualized (time of cervical dilatation; TCD). Serum samples were collected at 08h00 and 18h00 daily until TCD. All bitches underwent elective caesarean section at TCD. Results of this study show that approximately 5% and 10% of preparturient bitches will reach TCD within 12hr despite a serum progesterone level of at least 15.8nmol/L and 8.7nmol/L respectively. In addition, there is a 95% probability that a preparturient bitch will reach TCD within 48hr if her serum progesterone level is below 8.7nmol/L, and a 91% probability of her reaching TCD within 24hr if her serum progesterone level is below 3.18nmol/L. Approximately 90% of bitches that demonstrate a 20% increase in PGFM over a 12-hr period are likely to be within 36hr of TCD. These results provide useful benchmarks for the management of canine parturition.

Pregnancy maintenance following sequential induced prostaglandin pulses in beef cows

The relationship between the maternal endocrine environment and late embryonic mortality (> 28 d of gestation) in cattle is poorly defined. A definitive rise and alterations in secretion patterns of prostaglandin F2α (PGF2α) concentration without luteal regression is a trademark of this period. The objective was to evaluate whether consecutively induced PGF2α pulses would alter steroid hormone production and luteal blood perfusion potentially influencing pregnancy success. Pregnant beef cows (n = 12) were selected to receive either an oxytocin injection (OT, n = 8) or saline injection (CON, n = 4) on d 30 and 31 of gestation to stimulate sequential prostaglandin releases 24 h apart. Blood samples were collected every 30 min for 1 h before and continuing for 4 h post oxytocin administration. Luteal blood perfusion was measured via Doppler ultrasound at the beginning and end of the OT challenge. Concentrations of prostaglandin F2α metabolite (PGFM) were quantified to show effectiveness of the treatment while concentrations of progesterone, estradiol and pregnancy-associated glycoproteins (PAG) were measured to examine the effect of PGF2α release. Control animals exhibited no changes in any quantified hormone and an expected numerical increase in circulating PAG concentrations. Peak concentrations of PGFM in OT cows were observed 2 h post OT administration and concentrations returned to basal levels by the end of the sampling period. Peak concentrations of PGFM were decreased on d 31 compared to d 30. Following OT administration, progesterone and estradiol concentrations did not change in response to PGF2α release but were decreased on d 31 compared to d 30. There were no changes in luteal blood perfusion in response to PGF release on d 30 or d 31. Repeated PGF2α release may alter steroid hormone production; however, it does not negatively affect pregnancy status during the transition between early and late embryonic development.

Relationships between prostaglandin concentrations, a single nucleotide polymorphism in HSD17B12, and reproductive performance in dairy cows

Prostaglandins are involved in multiple processes important for fertility, with previous work in mice highlighting a potential role for the HSD17B12 gene in prostaglandin biosynthesis. This study aimed to determine the associations among circulating prostaglandin concentrations, a missense SNP in the HSD17B12 gene predicted to disrupt protein function, and fertility traits in first-lactation Holstein-Friesian dairy cows. We used a study population of approximately 500 animals specifically bred to have either a positive (POS, +5%) or negative (NEG, -5%) genetic merit for fertility (FertBV). Genotypes of a previously identified SNP (rs109711583) in HSD17B12 were determined, with 116 animals genotyped as AA, 215 genotyped as AG, and 153 genotyped as GG. Plasma concentrations of prostaglandin E2 and the PGF2α metabolite PGFM were determined at 3 time points (12 mo of age, 4 d postpartum, and 5 wk postpartum during first lactation) in a selection of animals with AA and GG genotypes from both the POS and NEG FertBV groups (n = 33-40 in each genotype for each FertBV group). Binary reproductive traits (yes or no) examined included submission for artificial breeding in the first 3 or 6 wk of the seasonal breeding period; conception to first service; conception during the first 6 wk of the breeding period; and pregnant at the end of the breeding period. Uterine health at 6 wk after calving was examined by evaluating the percentage of polymorphonuclear leukocytes following uterine cytology and by scoring vaginal discharge based on the presence of purulent material. The 3-wk submission rate was increased in animals that carried the G allele of the missense SNP in HSD17B12, but no differences were present among genotypes for 6-wk submission rate. The trait was additive, with each increase of the G allele increasing the 3-wk submission rate by 6 to 7%. We did not observe any consistent associations between SNP alleles and circulating PGE2 concentrations; however, a complex 3-way interaction among time, fertility group, and SNP allele was present for PGFM concentrations. Plasma concentrations of PGE2 were increased approximately 40% at 5 wk postpartum in animals that were submitted for breeding within 3 or 6 wk of the start of the breeding season, and in those that conceived during the first 6 wk of breeding, compared with those that did not. Plasma concentrations of PGFM were decreased approximately 20% in those animals that conceived to their first service and tended to be decreased in animals that were pregnant at the end of the breeding period, compared with those that were not. In summary, associations were observed between the SNP in HSD17B12 and submission rate by d 21 of the breeding season, as well as between circulating prostaglandin concentrations and fertility traits, but the SNP was not consistently linked to changes in prostaglandin concentrations. Thus, the association between submission rate by d 21 of the breeding season and the SNP in HSD17B12 were unlikely driven by changes in prostaglandins.

Accessory corpus luteum regression during pregnancy I: timing, physiology, and P4 profiles.

Inappropriate corpus luteum (CL) regression can produce pregnancy loss. An experimental model was utilized to investigate regression of accessory CL during pregnancy in dairy cows. Cows were bred (day 0) and treated with gonadotrophin-releasing hormone 6 days later to form accessory CL. Transrectal ultrasound (every other days) and blood samples for progesterone (P4; daily) were performed until day 56 of pregnancy. On day 28, 13 cows were confirmed pregnant, and accessory CL were found contralateral (n = 9) or ipsilateral (n = 4) to previous ovulation. On day 18, CL biopsy was performed to analyze mRNA expression for interferon-stimulated genes (ISGs). Luteolysis occurred more frequently in cows that had contralateral accessory CL (88.9% (8/9)) than in cows with ipsilateral accessory CL (0% (0/4)). Luteolysis of contralateral accessory CL occurred either earlier (days 19-23; 2/8) or later (days 48-53; 6/8) in pregnancy and occurred rapidly (24 h), based on daily P4. After onset of earlier or later accessory CL regression, circulating P4 decreased by 41.2%. There was no difference in luteal tissue mRNA expression for ISGs on day 18 between accessory and original CL and between CL that subsequently regressed or did not regress. On day 56, an oxytocin challenge dramatically increased prostaglandin F2α metabolite (PGFM) in all cows but produced no pregnancy losses, although cows with previous accessory CL regression had greater PGFM. In summary, ipsilateral accessory CL did not regress during pregnancy, whereas most contralateral CL regressed by 63 days of pregnancy, providing evidence for local mechanisms in regression of accessory CL and protection of CL during pregnancy.

Urinary lipid profile of atopic dermatitis in murine model and human patients.

Atopic dermatitis (AD) is the most common inflammatory skin disease in children. The serum level of thymus and activation-regulated chemokine (TARC) is a useful AD index to reflect disease severity; however, it requires blood collection from young children. In comparison, urine samples are easier to collect in a pediatric clinical setting. Here, we analyzed the lipids excreted in urine to identify a diagnostic biomarker for AD. We generated a murine dermatitis model by repeated topical application of 2,4-dinitrofluorobenzene (DNFB) or tape-stripping the dorsal skin. Lipid metabolites excreted in the urine were comprehensively analyzed using liquid chromatography-tandem mass spectrometry. To corroborate our findings, we also analyzed urine samples from patients with AD. DNFB application induced AD-like skin lesions, including epidermal thickening, infiltration of eosinophils and T cells, and an increase in Th2 cytokine levels. Assessment of lipids excreted in urine showed a dominance of prostaglandins (PGs), namely, a PGF2α metabolite (13,14-dihydro-15-keto-tetranor-PGF1α ), a PGE2 metabolite (13,14-dihydro-15-keto-tetranor-PGE2 ), and a PGD2 metabolite (13,14-dihydro-15-keto PGJ2 ). mRNA and protein expression of PGF2α , PGE2 , and PGD2 synthase was upregulated in DNFB-treated skin. The tape-stripping model also caused dermatitis but without Th2 inflammation; urine PGF2α and PGD2 metabolite levels remained unaffected. Finally, we confirmed that the urinary levels of the aforementioned PG metabolites, as well as PGI2 metabolite, 6,15-diketo-13,14-dihydro-PGF1α and arachidonic acid metabolite, 17-hydroxyeicosatetraenoic acid (17-HETE) increased in patients with AD. Our data highlights the unique urinary lipid profile in patients with AD, which may provide insight into novel urinary biomarkers for AD diagnosis.

Effect of route of administration of dinoprost tromethamine on plasma profiles of 13,14-dihydro-15-keto-prostaglandin F2α and progesterone in lactating Holstein cows

Lutalyse HighCon (dinoprost tromethamine; Zoetis) has been approved for use both intramuscularly and subcutaneously in lactating dairy cows, although the effect of route of administration on circulating 13,14-dihydro-15-keto-prostaglandin F2α (PGFM), the metabolite of PGF2α, has not been evaluated. Multiparous, lactating Holstein cows were submitted to an Ovsynch protocol in which the last GnRH treatment (G2) was designated as d 0. Cows were fitted with indwelling jugular catheters on d 6 and administered 25 mg of dinoprost tromethamine (2 mL of Lutalyse HighCon) on d 7 either subcutaneously in the neck (SC; n = 6) or intramuscularly in the semitendinosus muscle (IM; n = 6). Blood samples were collected every 15 min after treatment for 1.75 h, then every 2 h for 48 h, and at 60 and 72 h, with the last time point corresponding to when cows would have received timed AI at 72 h within an Ovsynch protocol. Circulating PGFM concentrations were greater for SC than for IM cows from 15 to 90 min after treatment, which resulted in a greater area under the PGFM curve during the first 90 min after treatment (means ± SEM; 1,664 ± 129 pg·h/mL vs. 1,146 ± 177 pg·h/mL for SC vs. IM cows, respectively). This resulted in complete luteolysis in all but one cow in the SC treatment at 56 h, when GnRH would have been administered if dinoprost tromethamine had been administered as part of an Ovsynch protocol for timed AI. For cows that underwent complete luteal regression, circulating P4 did not differ between treatments at any time point. Thus, although SC cows had increased circulating PGFM 15 to 90 min after treatment, there was no difference in circulating P4 during induced luteolysis based on route of dinoprost tromethamine administration.

Effects of estradiol treatments on PGF2α release in beef heifers submitted to estrous resynchronization 14 days after timed-AI

The effects of 17β‐estradiol (E2) or estradiol benzoate (EB) on PGF2α release were studied in bred-non-pregnant and pregnant Nelore beef heifers. The day of timed artificial insemination (TAI) was designated day 0 (D0), and a single treatment was given on D14. All heifers also received an intravaginal P4 device on D14, and were randomly assigned to three groups: Control (C, P4 device only, n = 12); E2 (1 mg E2 + 9 mg P4, n = 10); or EB (1 mg, n = 10). Blood samples were collected hourly for 8 hours after treatment (Hours 0–8) to measure plasma concentrations (pg/mL) of a PGF2α metabolite (PGFM). The P4 device was removed on D22 and pregnancy was diagnosed on D28. Pregnancy rate was not different among groups (C, n = 7/12; E2, n = 5/10; EB, n = 5/10). More (P < 0.05) heifers had a CV-identified prominent PGFM pulse (peak of > 100 pg/mL) in E2 group (6/10) than in EB (1/10) and C (0/12) groups. Hourly concentration of PGFM for Hours 0 to 8 showed significant effects of group and hour and an interaction of group by hour but did not show an interaction of group or hour with pregnancy status. In preliminary post-hoc analyses, PGFM concentrations during Hours 0 to 8 and pulse characteristics were analyzed within each pregnancy status. For the non-pregnant heifers, a group-by-hour interaction was detected tentatively indicating an increase (P < 0.005) in PGFM concentrations in E2 group from Hours 4 to 6 and in EB group at Hours 5 and 6. Maximum PGFM concentration during Hours 0 to 8 did not differ (P > 0.1) between E2 (124 ± 23) and EB (110 ± 30) groups, but was greater (P < 0.05) in each group than in C (32 ± 3). Furthermore, PGFM concentrations of pulses at the peak, amplitude, and area under pulse curve (pg/mL/h) were greater (P < 0.05) in E2 group than in C group whereas the EB group did not differ (P > 0.1) from the other groups. For pregnant heifers, no effects of group, hour, or their interaction were detected in PGFM concentrations during the hourly sessions, except that maximum PGFM concentration was greater (P < 0.05) in E2 than in EB and C groups. In addition, the number of prominent pulses was greater in E2 group than in Control or EB groups. In conclusion, PGFM increased earlier and in greater concentration combined for bred-non-pregnant and pregnant heifers treated 14 days after TAI with 1 mg E2 plus 9 mg P4 than with 1 mg EB. Tentatively, a positive effect for each of E2 and EB on PGFM concentrations was attenuated in pregnant heifers.

Concentrations of progesterone and a PGF2α metabolite during the interovulatory interval compared to the corresponding days of pregnancy in mares

The concentrations of progesterone (P4) and a metabolite of PGF2α (PGFM) in mares were compared between the interovulatory interval (IOI; n = 8) and the corresponding days of pregnancy (n = 9). In daily blood samples, P4 increased between the day of ovulation (Day 0) and ∼Day 6 and then gradually decreased until the beginning of luteolysis in the IOI group. Before the beginning of luteolysis, there were no significant differences in P4 concentrations between the IOI and early pregnancy. In the IOI, PGFM concentration on the day before the beginning of luteolysis began to increase (P < 0.04) and reached a maximum mean (42.9 ± 11.6 pg/mL) on Day 14. In pregnancy, a novel increase in PGFM occurred from Day 12 to a maximum mean on Day 15 (16.7 ± 3.1 pg/mL). Daily PGFM concentrations were not different between the two groups until the increase just before luteolysis in the IOI. During 8-h sessions of hourly blood sampling, the mean and maximum PGFM concentrations were significantly greater in IOI than in pregnancy for each 8-h session on Days 13, 14, and 15. The minimum was not different between groups on any day. Pulses of PGFM were identified by coefficient of variation during the hourly 8-h sessions on day-sets of Days 4–7, 9–11, and 13–16. Despite the PGFM increase in daily samples between Days 12 and 15 of pregnancy, the amplitude and peaks of CV-identified pulses did not differ in the pregnant mares among the three day-sets. The pulses were similarly small for day-sets 4–7 and 9–11 in the IOI and for all day-sets in pregnancy (eg, amplitude on Days 13–16: 43.4 ± 15.6 pg/mL vs 5.4 ± 1.1 pg/mL for IOI vs pregnancy). Hypothesis 1 was not supported that daily PGFM concentrations in an IOI increase at the intersection between the end of the rapid P4 increase and the gradual P4 decrease. Hypothesis 2 was supported that pregnant mares have low amplitude PGFM pulses during the days of the high amplitude pulses at luteolysis in the IOI.

Comparative biochemical profiles, utero-ovarian function, and fertility of the postpartum buffalo with and without subclinical endometritis.

In postpartum buffaloes, the process of uterine involution and changes in blood metabolic profile has not been studied in relation to development of subclinical endometritis (SCE). In this study, buffaloes (n = 100) approaching calving were identified. Weekly blood samples were collected on the day of calving up to 6weeks post-calving. The diameter of uterine horns and onset of ovarian cyclicity (corpus luteum) were recorded through ultrasonography. On the basis of polymorphonuclear cell (PMN) cell count in endometrial cytology at days 45-50 postpartum, buffaloes were divided into two groups, viz., with SCE (> 5% PMN; n = 38) and without SCE (≤ 5% PMN; n = 62). Buffaloes with SCE took longer (P < 0.05) time to complete uterine involution and had larger (P < 0.05) uterine horn diameter between 3rd and 6th weeks postpartum and lower prostaglandin F2α metabolite (PGFM) concentration on the day of calving (P < 0.05) and 1week (P < 0.001) post-calving than without SCE group. Buffaloes with SCE had lower (P < 0.001) concentration of glucose at weeks 2 and 3, higher (P < 0.001) β-hydroxybutyric acid (BHBA) at week 3, and lower serum albumin concentration throughout the sampling period (P < 0.05 to 0.001) except at 1week post-calving as compared to without SCE group. The urea concentration was significantly lower (P < 0.05 to 0.001) in buffaloes with SCE from 4weeks post-calving onwards than without SCE group. The calcium concentration was lower in buffaloes with SCE at weeks 5 (P < 0.001) and 6 (P < 0.05) postpartum, whereas the concentration of magnesium and phosphorus was uniform between the two groups. No significant (P > 0.05) difference in onset of ovarian cyclicity between the 2 groups was observed, whereas buffaloes with SCE had longer (P = 0.001) median days open (141days) than their counterpart (117days). The first service conception rate, cumulative pregnancy rate, and pregnancy rate at 150days postpartum were lower (P < 0.05) in buffaloes with SCE than without SCE group. In summary, higher BHBA and lower serum concentrations of glucose, albumin, urea, and calcium control onset of subclinical endometritis which in turn has negative impact on fertility of buffaloes.

Induced prostaglandin release alters steroid concentrations but not pregnancy survival in cows

Embryonic mortality (EM) is a major factor limiting reproductive efficiency in cattle, and despite negative connotations related to reproductive performance, prostaglandin F2α (PGF2α) is capable of being released by the uterus by Day 30 of gestation. Therefore, the objective was to evaluate differences in PGF2α release after an oxytocin challenge between cows with high circulating concentrations of pregnancy-associated glycoproteins (PAGs) vs low PAG because of the association of increased PAG concentrations with pregnancy success. At Day 30 of gestation, pregnant cows were divided into oxytocin treatment (OT; n = 13) and control (CON; n = 12) groups. Treatment cows were further subdivided by circulating PAG concentration (high PAG, n = 7; and low PAG, n = 6). Blood samples were collected every 30 min beginning 1 h before oxytocin administration and continuing for 4 h. Prostaglandin F2α metabolite (PGFM), progesterone, estradiol-17β (E2), and PAG concentrations were quantified. The peak concentration of PGFM occurred 2 h after oxytocin injection in treatment animals and returned to baseline levels by 4 h. No correlations were observed between PAG and PGFM, progesterone, or E2 concentrations (P > 0.05). There was no difference in initial or final PGFM concentrations between groups (P > 0.05). Progesterone and E2 concentrations decreased in cows after treatment of oxytocin (P < 0.05); however, only progesterone returned to basal concentrations by the end of the sampling period. In summary, cows with high vs low PAG concentrations at Day 30 of gestation have a similar PGFM response to oxytocin challenge.

Hematologic, prostaglandin F2α -metabolite, serum amyloid A, and serum iron changes in horses with experimentally induced endotoxemia.

Endotoxemia is a common and severe disease of horses. Most previous studies have monitored changes caused by a bolus dose of endotoxin over short time periods. We aimed to describe inflammatory responses to endotoxin with inflammatory and hematologic markers monitored over a longer time than has been performed in the past using more prolonged endotoxin exposures. Escherichia coli O55:B5 endotoxin was administered as a 6-hour continuous intravenous infusion of lipopolysaccharide (LPS) to eight horses. Blood cell counts, and prostaglandin F2α -metabolite (PGM), serum amyloid A (SAA), and serum total iron concentrations were monitored for up to 3 or 6days. An immediate and severe decrease in neutrophils and monocytes occurred in all horses, which subsequently changed to a moderate to strong neutrophilia and monocytosis that persisted for more than 78hours postinfusion (PI) of LPS. Lymphocyte and eosinophil numbers decreased gradually and then normalized after 66- and 78-hours PI, respectively. Mild to moderate, biphasic thrombocytopenia occurred. A pronounced, transient increase in PGM occurred between 1 and 7hours, peaking at 2hours. Serum amyloid A began to increase after 6hours PI and remained elevated after 72hours PI. Serum iron was decreased between 6 and 48hours. The clinical signs were most prominent during the first 24hours PI and subsided within 48hours PI. Neutrophilia, monocytoses, and high SAA concentrations were present in horses even after the clinical signs had subsided. Serum iron normalized before SAA. Knowledge of these findings is imperative when interpreting laboratory results in horses with possible endotoxin exposure.