Timing of prostaglandin F2α treatment in an estrogen-based protocol for timed artificial insemination or timed embryo transfer in lactating dairy cows

Objectives were to investigate progesterone concentrations and fertility comparing 2 different intervals from PGF2α treatment and induced ovulation in an estrogen-based ovulation synchronization protocol for timed artificial insemination (TAI) or timed embryo transfer (TET) in lactating dairy cows. A total of 1,058 lactating Holstein cows [primiparous (n=371) and multiparous (n=687)], yielding 34.1±0.33 kg of milk/d at various days in milk were randomly assigned to receive treatment with PGF2α on either d 7 or 8 of the following protocol: d 0: 2mg of estradiol benzoate + controlled internal drug release device; d 8: controlled internal drug release device removal + 1.0mg of estradiol cypionate; d 10: TAI or d 17: TET. Only cows with a corpus luteum at d 17 received an embryo and all cows received GnRH at TET. Pregnancy diagnoses were performed by detection (transrectal ultrasonography) of an embryo on d 28 or a fetus on d 60. Fertility [pregnancy per artificial insemination (P/AI) or pregnancy per embryo transfer (P/ET)] was affected by breeding technique (AI vs. ET) and time of PGF2α treatment (d 7 vs. 8) at the 28-d pregnancy diagnosis for TAI [32.9% (238) vs. 20.6% (168)] and TET cows [47% (243) vs. 40.7% (244)] and at the 60-d pregnancy diagnosis for TAI [30% (238) vs. 19.2% (168)] and TET cows [37.9% (243) vs. 33.5% (244)]. The progesterone (P4) concentration at d 10 altered fertility in TAI cows, with higher P/AI in cows with P4 concentration <0.1 ng/mL compared with cows with P4 concentration ≥0.1 ng/mL, and in ET cows, with higher P/ET in cows with P4 concentration <0.22 ng/mL compared with cows with P4 concentration ≥0.22 ng/mL. Prostaglandin F2α treatment at d 7 increased the percentage of cows with P4 <0.1 ng/mL on d 10 [39.4 (85) vs. 23.2 (54)]. Reducing the period between PGF2α and TAI from 72 to 48h in dairy cows resulted in a clear reduction in fertility in cows bred by TAI and a subtle negative effect in cows that received TET. The earlier PGF2α treatment benefits are most likely mediated through gamete transport, fertilization, or early embryo development and a more subtle effect of earlier PGF2α treatment that may be mediated through changes in the uterine or hormonal environment that manifests itself after ET on d 7. © 2013 American Dairy Science Association.

Uterine Involution, Fluid Accumulation and Ovarian Activity after Injection of Prostaglandin at Different Periods of Buffalo Puerperium

This study aimed to evaluate the effect of chloprostenol administration, at early or intermediary puerperium, under uterine involution, intrauterine fluid accumulation and ovarian activity return. 30 Murrah postpartum buffaloes were randomly divided into three groups: CONT (saline, n = 10); CLO2 (chloprostenol at days 2 and 5 postpartum, n = 10) and; CLO15 (chloprostenol at days 15 and 20 postpartum, n = 10). Gynecological exams were performed at days 2, 7, 14, 21 and 28 postpartum, when uterine involution degree (1 to 3 scale, by transrectal palpation), intrauterine fluid accumulation (0 to 3 scale, by ultrasound exam) and ovarian activity (B-mode ultrasound exam) were evaluated. CLO2 group presented higher uterine involution (2.00 +/- 0.23, 1.66 +/- 0.23, 1.58 +/- 0.23 for groups CLO2, CONT and CLO15, respectively) and faster ovarian activity return in relation to groups CONT and CLO15 (P < 0.05). Groups CLO2 and CLO15 showed lower intrauterine fluid accumulation compared to CONT group (2.04 +/- 0.20, 1.58 +/- 0.20, 1.92 +/- 0.20 for groups CONT, CLO2 and CLO15, respectively; P < 0.05). Prostaglandin analogue administration in postpartum buffalo benefited uterine involution, lochia expulsion and ovarian activity return, improving reproductive efficiency in this specie.

Cellular and molecular studies of the effects of a selective COX-2 inhibitor celecoxib in the cardiac cell line H9c2 and their correlation with death mechanisms

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Prostaglandin treatment at the onset of norgestomet and estradiol-based synchronization protocols did not alter the ovarian follicular dynamics or pregnancy per timed artificial insemination in cyclic Bos indicus heifers

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparison of selective and non selective cyclo-oxygenase 2 inhibitors in experimental colitis exacerbation: role of leukotriene B4 and superoxide dismutase

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeitos preventivos do treinamento físico na expressão das proteínas Cox-2 e Vegf de ratos tratados com dexametasona

Dexamethasone is a synthetic glucocorticoid widely used to treat allergic and inflammatory processes. This drug is used in three main situations, are used to contain acute or chronic inflammatory processes, or like immunosuppressive drug's. In these cases the patient will receive high doses for a chronic period and, therefore, has a much greater chance of adverse side effects, such as hypertension, diabetes and dyslipidemia. Dexamethasone promotes deleterious effects on the arachidonic acid pathway, when administered in high doses, because it is a potent anti-inflammatory drug. We recently demonstrated that dexamethasone significantly reduces the protein expression of vascular endothelial growth factor (VEGF) in both skeletal muscle and heart, but the mechanisms involved remain unclear. Meanwhile, exercise has been shown to be effective against high blood pressure, diabetes and dyslipidemia, promoting, among other factors, the increase in VEGF and angiogenesis. One possible explanation for these effects would be the creation of new vessels mediated by inflammation, or by the stimulation of the formation of products of the metabolism of arachidonic acid (AA), such as prostaglandin E2 (PGE2) and VEGF, by increasing the stimulation of the enzymes cyclooxygenase 1 and 2 (COX-1 and COX-2). Little is known about the preventive effects of training on the action of dexamethasone in the arachidonic acid pathway. Therefore, the aim of this study was to determine whether aerobic exercise training, performed before and concomitant treatment with dexamethasone, was able to prevent the effects of the dexamethasone in the protein expression of COX-2 and VEGF. For this, we used young Wistar rats (n = 40) which were randomly divided into 4 groups: sedentary control (SC), sedentary and treated with dexamethasone (SD), trained control (TC) and trained and treated with dexamethasone (TD). These rats performed aerobic exercise training, 60% of maximum capacity, 5

Luteal changes after treatment with sub-luteolytic doses of prostaglandin (cloprostenol sodium) in cattle

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Expression of receptors for ovarian steroids and prostaglandin E2 in the endometrium and myometrium of mares during estrus, diestrus and early pregnancy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Increased cyclooxygenase-2 and vascular endothelial growth factor protein expression is associated with canine prostatic carcionogenesis process

Background: COX-2 is one of the most important prostaglandin involved in urologic cancer and seems to be associated with tumor progression, invasion, and metastasis. In addition, several effects have been reported for VEGF, including inducing angiogenesis, promoting cell migration, and inhibiting apoptosis. COX2 and VEGF up-regulation have been reported in human prostate cancer. Due to the importance of canine natural model for prostate cancer, the aim of this study was to evaluate COX-2 and VEGF protein expression in canine carcinogenic process. Material and Methods: Seventy-four prostatic tissues from dogs were selected to be evaluated for protein expression by immunohistochemistry (IHC), including: 10 normal prostatic tissues, 20 benign prostatic hyperplasias (BPH), 25 proliferative inflammatory atrophies (PIA) and 20 prostatic carcinomas (PCa). COX-2 and VEGF were detected using the monoclonal antibody CX-294 (1:50 dilution, Dako Cytomation and sc-53463 (1:100 dilution, Santa Cruz), respectively. The immunolabelling was performed by a polymer method (Histofine, Nichirei Biosciences). All reaction included negative controls by omitting the primary antibody. The percentage of C-MYC, E-cadherin, and p63- positive cells per lesion was evaluated according to Prowatke et al. (2007). The samples were scored separately according to staining intensity and graded semi-quantitatively as negative, weakly positive (1), moderately positive, and strongly positive. The score was done in one 400 magnification field, considering only the lesion, since this was done in a TMA core of 1 mm. For statistical analyses, the immunostaining classifications were reduced to two categories: negative and positive. The negative category included negative and weakly positive staining. Chi-square or Fisher exact test was used to determine the association between the categorical variables. Results: The COX-2 protein expression was elevated in the cytoplasm of the canine PCa and PIA compared to normal prostate (p=0.002). VEGF protein expression was increased in 94.75% of the PCa and 100% of the PIA compared with to normal prostate (p = 0.001). No difference was found when compared normal prostate with BPH. Conclusions: This study has demonstrated that the carcinogenesis of canine prostatic tissue may be related to gain of COX-2 and VEGF protein expression.

Exenatide and sitagliptin decrease interleukin 1β, matrix metalloproteinase 9, and nitric oxide synthase 2 gene expression but does not reduce alveolar bone loss in rats with periodontitis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Prostaglandin treatment at the onset of norgestomet and estradiol-based synchronization protocols did not alter the ovarian follicular dynamics or pregnancy per timed artificial insemination in cyclic Bos indicus heifers

The aim of the present study was to evaluate the effects of the PGF2˛treatment givenat the onset of a synchronization of ovulation protocol using a norgestomet (NORG) earimplant on ovarian follicular dynamics (Experiment 1) and pregnancy per AI (P/AI; Exper-iment 2) in cyclic (CL present) Bos indicus heifers. In Experiment 1, a total of 46 heiferswere presynchronized using two consecutive doses of PGF2˛12 days apart. At first dayof the synchronization protocol the heifers received implants containing 3 mg of NORGand 2 mg of estradiol benzoate (EB). At the same time, heifers were randomly assignedto receive 150 mg of d-cloprostenol (n = 23; PGF2˛) or no additional treatment (n = 23;Control). When the ear implants were removed 8 days later, all heifers received a PGF2˛treatment and 1 mg of EB was given 24 h later. The follicular diameter and interval toovulation were determined by transrectal ultrasonography. No effects of PGF2˛treat-ment on the diameter of the largest follicle present were observed at implant removal(PGF2˛= 9.8 ± 0.4 vs. Control = 10.0 ± 0.3 mm; P = 0.73) or after 24 h (PGF2˛= 11.1 ± 0.4 vs.Control = 11.0 ± 0.4 mm; P = 0.83). No differences in the time of ovulation after ear implantremoval (PGF2˛= 70.8 ± 1.2 vs. Control = 73.3 ± 0.9 h; P = 0.10) or in the ovulation rate(PGF2˛= 87.0 vs. Control = 82.6%; P = 0.64) between treatments were observed. In Experi-ment 2, 280 cyclic heifers were synchronized using the same experimental design describedabove (PGF2˛; n = 143 and Control; n = 137), at random day of the estrous cycle. All heifersreceived 300 IU of equine chorionic gonadotropin (eCG) and 0.5 mg of estradiol cypionate(as ovulatory stimulus) when the NORG ear implants were removed. Timed artificial insem-ination (TAI) was performed 48 h after implant removal and the pregnancy diagnosis wasconducted 30 days later. No effects on the P/AI due to PGF2˛treatment were observed(PGF2˛= 51.7 vs. Control = 57.7%; P = 0.29). In conclusion, PGF2˛treatment at the onset ofNORG-based protocols for the synchronization of ovulation did not alter the ovarian follic-ular responses or the P/AI in cyclic Bos indicus beef heifers synchronized for TAI.

Effects of a single administration of prostaglandin F2alpha, or a combination of prostaglandin F2alpha and prostaglandin E2, or placebo on fertility variables in dairy cows 3-5 weeks post partum, a randomized, double-blind clinical trial

BACKGROUND: Delayed uterine involution has negative effects on the fertility of cows; use of prostaglandin F2alpha alone as a single treatment has not been shown to consistently improve fertility. Combined administration of PGF2alpha and PGE2 increased uterine pressure in healthy cows. We hypothesized, that the combination of both prostaglandins would accelerate uterine involution and have, therefore, a positive effect on fertility variables. In commercial dairy farming, the benefit of a single post partum combined prostaglandin treatment should be demonstrated. METHODS: 383 cows from commercial dairy farms were included in this study. Uterine size and secretion were evaluated at treatment 21-35 days post partum and 14 days later. Cows were randomly allocated to one of three treatment groups: PGF2alpha and PGE2, PGF2alpha or placebo. For every animal participating in the study, the following reproduction variables were recorded: Interval from calving to first insemination, days open, number of artificial inseminations (AI) to conception; subsequent treatment of uterus, subsequent treatment of ovaries. Plasma progesterone level at time of treatment was used as a covariable. For continuous measurements, analysis of variance was performed. Fisher's exact test for categorical non-ordered data and exact Kruskal-Wallis test for ordered data were used; pairwise group comparisons with Bonferroni adjustment of significance level were performed. RESULTS: There was no significant difference among treatment groups in uterine size. Furthermore, there was no significant difference among treatments concerning days open, number of AI, and subsequent treatment of uterus and ovaries. Days from calving to first insemination tended to be shorter for cows with low progesterone level given PGF2alpha and PGE2 in combination than for the placebo-group (P = 0.024). CONCLUSION: The results of this study indicate that the administration of PGF2alpha or a combination of PGF2alpha and PGE2 21 to 35 days post partum had no beneficial effect upon measured fertility variables. The exception was a tendency for a shorter interval from calving to first insemination after administration of the combination of PGF2alpha and PGE2, as compared to the placebo group. Further research should be done in herds with reduced fertility and/or an increased incidence of postpartum vaginal discharge.

Prostaglandin E1 testing in heart failure-associated pulmonary hypertension enables transplantation: the PROPHET study

BACKGROUND: Elevated pulmonary vascular resistance (PVR) is relevant to prognosis of congestive heart failure and heart transplantation. Proof of reversibility by pharmacologic testing in potential transplantation candidates is important because it indicates a reduced probability of right ventricular failure or death in the early post-transplant period. This study aimed to clarify the possible extent of acute reversibility of elevated PVR in a large, consecutive cohort of heart transplant candidates. METHODS: This study included 208 consecutive patients (age 52 +/- 10 years, 89% men and 11% women, ejection fraction 21 +/- 9%, Vo2max 12.6 +/- 4.2 ml/kg/min) being evaluated for heart transplantation in 7 transplant centers in Germany and Switzerland. Testing was performed with increasing intravenous doses of prostaglandin E1 (PGE1; average maximum dose 173 +/- 115 ng/kg/min for at least 10 minutes) in 92 patients exhibiting a baseline PVR of > 2.5 Wood units (WU) and/or a transpulmonary gradient (TPG) of > 12 mm Hg. RESULTS: PGE1 testing lowered PVR from 4.1 +/- 2.0 to 2.1 +/- 1.1 WU (p < 0.01), increased cardiac output from 3.8 +/- 1.0 to 5.0 +/- 1.5 liters/min (p < 0.01), and decreased TPG from 14 +/- 4 to 10 +/- 3 mm Hg (p < 0.01), mean pulmonary artery pressure (PAM) from 39 +/- 9 to 29 +/- 9 mm Hg (p < 0.01) and mean pulmonary capillary wedge pressure (PCWP) from 24 +/- 7 to 19 +/- 9 mm Hg (p < 0.01). Mean aortic pressure (MAP) decreased to 85% and systemic vascular resistance (SVR) to 65% of baseline values (p < 0.01). Symptomatic systemic hypotension was not observed. For the whole population the percentage of patients with PVR > 2.5 WU was reduced from 44.2% to 10.5% with PGE1. PVR decreased in each patient; only 2 patients (1%) remained ineligible for listing because of a final PVR of > 4.0 WU. TPG, ejection fraction and male gender were independent predictors of reversibility of PVR. CONCLUSIONS: Elevated PVR in heart transplant candidates is highly reversible and can be normalized during acute pharmacologic testing with PGE1.

Sphingosine 1-phosphate (S1P) induces COX-2 expression and PGE2 formation via S1P receptor 2 in renal mesangial cells

Understanding the mechanisms of sphingosine 1-phosphate (S1P)-induced cyclooxygenase (COX)-2 expression and prostaglandin E2 (PGE2) formation in renal mesangial cells may provide potential therapeutic targets to treat inflammatory glomerular diseases. Thus, we evaluated the S1P-dependent signaling mechanisms which are responsible for enhanced COX-2 expression and PGE2 formation in rat mesangial cells under basal conditions. Furthermore, we investigated whether these mechanisms are operative in the presence of angiotensin II (Ang II) and of the pro-inflammatory cytokine interleukin-1β (IL-1β). Treatment of rat and human mesangial cells with S1P led to concentration-dependent enhanced expression of COX-2. Pharmacological and molecular biology approaches revealed that the S1P-dependent increase of COX-2 mRNA and protein expression was mediated via activation of S1P receptor 2 (S1P2). Further, inhibition of Gi and p42/p44 MAPK signaling, both downstream of S1P2, abolished the S1P-induced COX-2 expression. In addition, S1P/S1P2-dependent upregulation of COX-2 led to significantly elevated PGE2 levels, which were further potentiated in the presence of Ang II and IL-1β. A functional consequence downstream of S1P/S1P2 signaling is mesangial cell migration that is stimulated by S1P. Interestingly, inhibition of COX-2 by celecoxib and SC-236 completely abolished the migratory response. Overall, our results demonstrate that extracellular S1P induces COX-2 expression via activation of S1P2 and subsequent Gi and p42/p44 MAPK-dependent signaling in renal mesangial cells leading to enhanced PGE2 formation and cell migration that essentially requires COX-2. Thus, targeting S1P/S1P2 signaling pathways might be a novel strategy to treat renal inflammatory diseases.

CREB mediates prostaglandin F2alpha-induced MUC5AC overexpression.

Mucus secretion is an important protective mechanism for the luminal lining of open tubular organs, but mucin overproduction in the respiratory tract can exacerbate the inflammatory process and cause airway obstruction. Production of MUC5AC, a predominant gel-forming mucin secreted by airway epithelia, can be induced by various inflammatory mediators such as prostaglandins. The two major prostaglandins involved in inflammation are PGE(2) and PGF(2alpha). PGE(2)-induced mucin production has been well studied, but the effect of PGF(2alpha) on mucin production remains poorly understood. To elucidate the effect and underlying mechanism of PGF(2alpha) on MUC5AC production, we investigated the signal transduction of PGF(2alpha) associated with this effect using normal human tracheobronchial epithelial cells. Our results demonstrated that PGF(2alpha) induces MUC5AC overproduction via a signaling cascade involving protein kinase C, ERK, p90 ribosomal S6 protein kinase, and CREB. The regulation of PGF(2alpha)-induced MUC5AC expression by CREB was further confirmed by cAMP response element-dependent MUC5AC promoter activity and by interaction between CREB and MUC5AC promoter. The abrogation of all downstream signaling activities via suppression of each signaling molecule along the pathway indicates that a single pathway from PGF(2alpha) receptor to CREB is responsible for inducing MUC5AC overproduction. As CREB also mediates mucin overproduction induced by PGE(2) and other inflammatory mediators, our findings have important clinical implications for the management of airway mucus hypersecretion.