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Although hormonally-derived female sex pheromones have been well described in approximately a dozen species of teleost fish, only a few male sex pheromones have been characterized and the neuroendocrine underpinnings of behavioral responsiveness to them is not understood. Herein, we describe a study that addresses this question using the goldfish, Carassius auratus, an important model species of how hormones drive behavior in egg-laying teleost fishes. Our study had four components. First, we examined behavioral responsiveness of female goldfish and found that when injected with prostaglandin F2α (PGF2α), a treatment that drives female sexual receptivity, and found that they became strongly and uniquely attracted to the odor of conspecific mature males, while non-PGF2α-treated goldfish did not discern males from females. Next, we characterized the complexity and specificity of the male pheromone by examining the responsiveness of PGF2α-treated females to the odor of either mature male conspecifics or male common carp odor, as well as their nonpolar and polar fractions. We found that the odor of male goldfish was more attractive than that of male common carp, and that its activity was attributable to both its nonpolar and polar fractions with the later conveying information on species-identity. Third, we hypothesized that androstenedione (AD), a 19-carbon sex steroid produced by all male fish might be the nonpolar fraction and tested whether PGF2α-treated goldfish were attracted to either AD alone or as part of a mixture in conspecific water. We found that while AD was inactive on its own, it became highly attractive when added to previously unattractive female conspecific water. Lastly, in a test of whether nonhormonal conspecific odor might determine species-specificity, we added AD to water of three species of fish and found that while AD made goldfish water strongly attractive, its effects on other species holding water were small. We conclude that circulating PGF2α produced at the time of ovulation induces behavioral sensitivity to a male sex pheromone in female goldfish and that this male pheromone is comprised of AD and a mixture of body metabolites. Because PGF2α commonly mediates ovulation and female sexual behavior in egg-laying fishes, and AD is universally produced by male fishes as a precursor to testosterone, we suggest that these two hormones may have similar roles mediating male-female behavior and communication in many species of fish., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.)

Introduction: The amount of prostaglandin F 2α (PGF 2α ) in the uterine lumen increases during the window of implantation in many mammals, including humans. We hypothesized that PGF 2α regulates processes related to human embryo implantation., Methods: The effect of PGF 2α was studied using an in vitro model of human extravillous trophoblast (EVT) cell line (HTR-8/SVneo). Adhesion, proliferation, invasion and migration assays, zymography for metalloproteinases (MMP) activity, and gene/protein expression analyses were applied. Doses of 100 nM and/or 1 μM of PGF 2α and fluprostenol were used. PGF 2α receptor (PTGFR), MMP9 and MMP2 proteins in the human first trimester placenta were localized by immunohistochemistry and immunofluorescence., Results: This study is the first reporting the expression of PTGFR protein in the first trimester placenta, as well as in HTR-8/SVneo cells. PGF 2α and fluprostenol increased HTR-8/SVneo cell proliferation and adhesion to extracellular matrix protein (P < 0.05). This effect was abolished by mitogen activated protein kinases (MAPK) inhibitor. PGF 2α induced phosphorylation of focal adhesion kinase and MAPK1/3 (P < 0.05). PGF 2α increased mRNA content and protein activity of MMP9, and gene and protein expression of interleukin-6 (P < 0.05). EVT cell migration and invasiveness were stimulated by PGF 2α (P < 0.05). The PGF 2α effect on cell invasion was reduced by inhibitors of MMP2, MMP9 and mTOR. In all experiments, the stimulatory effects of PGF 2α were diminished by using a PTGFR antagonist., Discussion: Our findings suggest a significant role for PGF 2α in mechanisms associated with implantation. PGF 2α acting by PTGFR in HTR-8/SVneo cells stimulates their adhesion and proliferation through the MAPK signaling pathway and increases invasiveness inducing MMP proteolytic activity and mTOR signaling., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The new corpora lutea (CLs) in pigs are formed from the preovulatory follicles after the luteinizing hormone (LH) surge. However, total autonomy and independence of CLs from LH up to Day 12 of cycle has recently been questioned. Transformation of estrous cycle CL to CL of pregnancy initiated by embryonic signals requires not only the cessation of prostaglandin F2 (PGF 2α ) supply to the luteal tissue but also needs the CL to overcome luteolytic acquisition and/or changing its sensitivity to PGF 2α during Days 12-14 of pregnancy. The luteolytic cascade is prevented by inhibition of lymphocyte infiltration and leucocyte recruitment, limitation of cell apoptosis, upregulation of pregnancy-associated genes and an enhanced antiluteolytic role of PGE 2 Our 'two-signal switch hypothesis' highlights the importance of post PGF 2α and PGE 2 receptor signaling pathways activation in CLs during luteolysis and rescue. The 'luteolytic switch' involves increased expression of many regression mediators and activation of the post PTGFR signaling pathway. The 'rescue switch' initiated by embryonic signals - estradiol 17β and PGE 2 - induces post PTGER2/4 pathway, turning the 'luteolytic switch' off and triggering activity of genes responsible for CL maintenance. In mid and late pregnancy, CLs are maintained by LH and the synergistic action of metabolic hormones. This paper provides an outline of recent views on CL regression, rescue and maintenance during pregnancy in pigs that conflict with previous paradigms and highlights new findings regarding the actions of prostaglandins, role of microRNAs (miRNA) and immune system and signaling pathways governing the life cycle of porcine CL., (© 2018 Society for Reproduction and Fertility.)

Cortical spreading depression (CSD) is considered a significant phenomenon for human neurological conditions and one of its key signatures is the development of persistent cortical oligemia. The factors underlying this reduction in cerebral blood flow (CBF) remain incompletely understood but may involve locally elaborated vasoconstricting eicosanoids. We employed laser Doppler flowmetry in urethane-anesthetized rats, together with a local pharmacological blockade approach, to test the relative contribution of cyclooxygenase (COX)-derived prostanoids to the oligemic response following CSD. Administration of the non-selective COX inhibitor naproxen completely inhibited the oligemic response. Selective inhibition of COX-1 with SC-560 preferentially reduced the early reduction in CBF while selective COX-2 inhibition with NS-398 affected only the later response. Blocking the action of thromboxane A 2 (TXA 2 ), using the selective thromboxane synthase inhibitor ozagrel, reduced only the initial CBF decrease, while inhibition of prostaglandin F2alpha action, using the selective FP receptor antagonist AL-8810, blocked the later phase of the oligemia. Our results suggest that the long-lasting oligemia following CSD consists of at least two distinct temporal phases, mediated by preferential actions of COX-1- and COX-2-derived prostanoids: an initial phase mediated by COX-1 that involves TXA 2 followed by a later phase, mediated by COX-2 and PGF2alpha.

The aim of the present study was to examine the effects of luteotropic and luteolytic factors on the mRNA and protein levels of progesterone receptor isoforms A (PGRA) and B (PGRB) in the bovine endometrium. Endometrial slices from Days 6-10 and 17-20 of the oestrous cycle were treated with LH (100ngmL -1 ), oestradiol (E2; 1×10 -8 M), prostaglandin (PG) E 2 (1×10 -6 M) and PGF 2α (1×10 -6 M) and the nitric oxide donor NONOate (1×10 -4 M); these treatments lasted for 6h for mRNA expression analysis and 24h for protein expression analysis. On Days 6-10 of the oestrous cycle PGRAB (PGRAB; the entire PGRA mRNA sequence is common to the PGRB mRNA sequence) mRNA expression in endometrial slices was enhanced by E2 treatment (P<0.001), whereas PGRB mRNA expression was increased by LH (P<0.001), E2 (P<0.05) and NONOate (P<0.05) treatment. On Days 17-20, PGRAB mRNA expression increased after E2 (P<0.001) and PGE 2 (P<0.05) treatment; PGRB mRNA expression was increased by PGE 2 (P<0.05) and PGF 2α (P<0.01) treatment, but decreased by LH (P<0.05). On Days 6-10 protein levels of PGRA were stimulated by E2 (P<0.01), whereas PGRB protein levels were increased by LH (P<0.05) and E2 (P<0.05). On Days 17-20 of the oestrous cycle, PGRA protein levels were enhanced by E2 (P<0.05) and PGF 2α (P<0.05), whereas PGRB protein levels were stimulated by PGE 2 (P<0.05) and PGF 2α (P<0.001). These data suggest that luteotropic and luteolytic factors affect PGRA and PGRB mRNA and protein levels, and this may regulate the effects of progesterone on endometrial cells.

Luteinized unruptured follicle (LUF) syndrome is a recurrent anovulatory dysfunction that affects up to 23% of women with normal menstrual cycles and up to 73% with endometriosis. Mechanisms underlying the development of LUF syndrome in mares were studied to provide a potential model for human anovulation. The effect of extended increase in circulating LH achieved by administration of recombinant equine LH (reLH) or a short surge of LH and decrease in progesterone induced by prostaglandin F2α (PGF2α) on LUF formation (Experiment 1), identification of an optimal dose of COX-2 inhibitor (flunixin meglumine, FM; to block the effect of prostaglandins) for inducing LUFs (Experiment 2), and evaluation of intrafollicular endocrine milieu in LUFs (Experiment 3) were investigated. In Experiment 1, mares were treated with reLH from Day 7 to Day 15 (Day 0=ovulation), PGF2α on Day 7, or in combination. In Experiment 2, FM at doses of 2.0 or 3.0 mg/kg every 12 h and human chorionic gonadotropin (hCG) (1500 IU) were administered after a follicle ≥32 mm was detected. In Experiment 3, FM at a dose of 2.0 mg/kg every 12 h plus hCG was used to induce LUFs and investigate the intrafollicular endocrine milieu. No LUFs were induced by reLH or PGF2α treatment; however, LUFs were induced in 100% of mares using FM. Intrafollicular PGF2α metabolite, PGF2α, and PGE2 were lower and the ratio of PGE2:PGF2α was higher in the induced LUF group. Higher levels of intrafollicular E2 and total primary sex steroids were observed in the induced LUF group along with a tendency for higher levels of GH, cortisol, and T; however, LH, PRL, VEGF-A, and NO did not differ between groups. In conclusion, this study reveals part of the intrafollicular endocrine milieu and the association of prostaglandins in LUF formation, and indicates that the mare might be an appropriate model for studying the poorly understood LUF syndrome., (© 2016 Society for Reproduction and Fertility.)

In a previous report, we demonstrated the inverse association of high serum 8-isoprostane levels, a marker for oxidative stress, with decreased serum IgG antibodies to oral bacteria. The association between increased serum IgG with increased plaque and periodontitis (increased probing depths) was attenuated by high systemic oxidative stress. Other investigations have reported a role for systemic oxidative stress as a stimulus of hepatic C-reactive protein (CRP) response. These observations led us to hypothesize that the reported relationship of periodontitis to elevated serum CRP, a systemic inflammatory marker, may be modified by oxidative stress and that the levels of serum antibodies to oral bacteria might be an intermediary explanatory variable linking the association of systemic oxidative stress, periodontal disease, and levels of CRP. This hypothesis was explored as a secondary analysis of the Dental ARIC (Atherosclerosis Risk in Communities) study using serum levels of CRP, serum IgG levels to 16 oral organisms, serum levels of 8-isoprostane, and periodontal status. The findings indicate periodontitis is associated with high CRP in the presence of elevated oxidative stress that serves to suppress the IgG response. Only within the highest 8-isoprostane quartile was periodontitis (pocket depth) associated with increased serum CRP levels (P = 0.0003). Increased serum IgG antibody levels to oral bacteria were associated with lowered serum CRP levels. Thus, systemic oxidative stress, which has been demonstrated to be associated with increased levels of CRP in other studies, appears to be associated with the suppression of bacterial-specific IgG levels, which in the presence of periodontal disease can result in an enhanced systemic CRP response. Conversely, individuals with increased serum IgG antibodies to plaque bacteria exhibit lowered serum CRP levels. These 2 factors, oxidative stress and the serum IgG response, appear to function in opposing directions to modify serum levels of CRP and the association with periodontitis., (© International & American Associations for Dental Research 2015.)

Prostaglandin F2α analogs, commonly prescribed for glaucoma treatment, have been shown to induce side effects such as cutaneous hypertrichosis and hyperpigmentation. Therefore, these medications have theoretic applications in the treatment of alopecia and disorders of hypopigmentation. We reviewed the literature to find original studies assessing the use of prostaglandin F2α analogs in these settings. Studies and reports were analyzed in regards to androgenic alopecia, alopecia areata, chemotherapy-induced alopecia, vitiligo, and hypopigmented scarring. Based on the results of these studies, and consideration of pathophysiologic mechanism, the most promising applications for prostaglandin F2α analogs include androgenic alopecia, chemotherapy-induced alopecia, and alopecia areata concurrently treated with corticosteroids., (Copyright © 2014 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

Beside amyloid-β plaques and neurofibrillary tangles, brain oxidative damage has been constantly implicated in Alzheimer's disease (AD) pathogenesis. Numerous studies demonstrated that F2-isoprostanes, markers of in vivo lipid peroxidation, are elevated in AD patients and mouse models of the disease. Previously, we showed that the 8-isoprostaneF2α, (8ISO) increases brain amyloid-β levels and deposition in the Tg2576 mice. However, no data are available on its effects on behavior and tau metabolism. To this end, we characterize the behavioral, biochemical, and neuropathologic effects of 8ISO in the triple transgenic mouse model. Compared with controls, mice receiving 8ISO showed significant memory deficits, increase in tau phosphorylation, activation of the cyclin kinase 5 pathway, and neuroinflammation. All these effects were blocked by pharmacologic blockade of the thromboxane receptor. Our findings establish the novel functional role that oxidative stress via the formation of this isoprostane plays in the development of cognitive impairments and AD-related tau neuropathology. It provides important preclinical support to the neurobiological importance of the thromboxane receptor as an active player in the pathogenesis of AD., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The bovine corpus luteum (CL) is hypothesized to utilize a local auto-amplification system for prostaglandin (PG) F2α production. The objective of the present study was to determine if such a PGF2α auto-amplification system exists in the bovine CL, and if so, which factors regulate it. PGF2α significantly stimulated intra-luteal PGF2α production in all luteal phases, but did not affect PGE2 production. The stimulatory effect of exogenous PGF2α on CL PGF2α production was lower at the early luteal phase. Indomethacin, an inhibitor of prostaglandin-endoperoxide synthase (PTGS), significantly suppressed the PGF2α-stimulated PGF2α production by luteal tissue, indicating that the PGF2α in the medium was of luteal origin. Consistent with these secreted-PGF2α profiles, PGF2α receptor (PTGFR) protein expression was higher during the mid and late luteal phases than at early and developing luteal phases. Treatment of cultured bovine luteal cells obtained from the mid-luteal phase with PGF2α (1 µM) significantly increased the expressions of PTGS2, PGF synthase (PGFS), and carbonyl reductase1 (CBR1) at 24 hr post-treatment. Together, these results suggest the presence of a local auto-amplification system for PGF2α mediated by PTGS2, PGFS, and CBR1 in the bovine CL, which may play an important role in luteolysis., (© 2014 Wiley Periodicals, Inc.)

Although calcium (Ca(2+)) is accepted as an intracellular mediator of prostaglandin F2 alpha (PGF2alpha) actions on luteal cells, studies defining mechanisms of Ca(2+) homeostasis in bovine corpora lutea (CL) are lacking. The increase in intracellular Ca(2+) concentration ([Ca(2+)]i) induced by PGF2alpha in steroidogenic cells from mature CL is greater than in those isolated from developing CL. Our hypothesis is that differences in signal transduction associated with developing and mature CL contribute to the increased efficacy of PGF2alpha to induce a Ca(2+) signal capable of inducing regression in mature CL. To test this hypothesis, major genes participating in Ca(2+) homeostasis in the bovine CL were identified, and expression of mRNA, protein, or activity, in the case of phospholipase Cbeta (PLCbeta), in developing and mature bovine CL was compared. In addition, we examined the contribution of external and internal Ca(2+) to the PGF2alpha stimulated rise in [Ca(2+)]i in LLCs isolated from developing and mature bovine CL. Three differences were identified in mechanisms of calcium homeostasis between developing and mature CL, which could account for the lesser increase in [Ca(2+)]i in response to PGF2alpha in developing than in mature CL. First, there were lower concentrations of inositol 1,4,5-trisphosphate (IP3) after similar PGF2alpha challenge, indicating reduced phospholipase C beta (PLCbeta) activity, in developing than mature CL. Second, there was an increased expression of sorcin (SRI) in developing than in mature CL. This cytoplasmic Ca(2+) binding protein modulates the endoplasmic reticulum (ER) Ca(2+) release channel, ryanodine receptor (RyR), to be in the closed configuration. Third, there was greater expression of ATP2A2 or SERCA, which causes calcium reuptake into the ER, in developing than in mature CL. Developmental differences in expression detected in whole CL were confirmed by Western blots using protein samples from steroidogenic cells isolated from developing and mature CL. Localization of these genes in steroidogenic luteal cells was confirmed by immunohistochemistry. Therefore, it is concluded that the cellular mechanisms that allow PGF2alpha to induce a calcium signal of greater magnitude in mature than in developing CL involve 1) greater PLCbeta activity with enhanced generation of IP3, 2) an enhanced Ca(2+) release from the ER via unrestrained RYR2 due to a decrease in SRI expression, and 3) a reduction in calcium reuptake to the ER due to lower expression of ATP2A2. Accordingly, the increase in [Ca(2+)]i induced by PGF2alpha in mature large steroidogenic cells had less dependency from extracellular calcium than in those isolated from immature CL.

The mechanisms regulating sexual behaviours in female vertebrates are still poorly understood, mainly because in most species sexual displays in females are more subtle and less frequent than displays in males. In a sex-role reversed population of a teleost fish, the peacock blenny Salaria pavo, an external fertilizer, females are the courting sex and their sexual displays are conspicuous and unambiguous. We took advantage of this to investigate the role of ovarian-synthesized hormones in the induction of sexual displays in females. In particular, the effects of the sex steroids oestradiol (E2) and testosterone (T) and of the prostaglandin F2α (PGF2α) were tested. Females were ovariectomized and their sexual behaviour tested 7 days (sex steroids and PGF2α) and 14 days (sex steroids) after ovariectomy by presenting females to an established nesting male. Ovariectomy reduced the expression of sexual behaviours, although a significant proportion of females still courted the male 14 days after the ovary removal. Administration of PGF2α to ovariectomized females recovered the frequency of approaches to the male's nest and of courtship displays towards the nesting male. However, E2 also had a positive effect on sexual behaviour, particularly on the frequency of approaches to the male's nest. T administration failed to recover sexual behaviours in ovariectomized females. These results suggest that the increase in E2 levels postulated to occur during the breeding season facilitates female mate-searching and assessment behaviours, whereas PGF2α acts as a short-latency endogenous signal informing the brain that oocytes are mature and ready to be spawned. In the light of these results, the classical view for female fishes, that sex steroids maintain sexual behaviour in internal fertilizers and that prostaglandins activate spawning behaviours in external fertilizers, needs to be reviewed.

Objective: To elucidate the functional responses of isolated human urethral smooth muscle to various agents known to exert smooth muscle contraction or relaxation., Methods: Specimens of penile urethra were obtained from male patients who had undergone male-to-female gender reassignment surgery. Using the tissue bath technique, the contraction induced by increasing concentrations (1 nM-10 μM) of norepinephrine, phenylephrine, acetylcholine, carbachol, prostaglandin F2α, endothelin 1, angiotensin II, and oxytocin was measured. In another set-up, the effects of C-type natriuretic peptide (0.1 nM-1 μM), sodium nitroprusside, sildenafil, forskolin, alpha2-antagonist delquamine, and acetylcholine (1 nM/10 nM-10 μM) on the tension induced by norepinephrine were investigated. The production of cyclic guanosine monophosphate (GMP) and cyclic adenosine monophosphate (AMP) was measured by means of specific radioimmunoassays., Results: Endothelin 1, oxytocin, prostaglandin F2α, norepinephrine, and phenylephrine induced dose-dependent contraction of the isolated urethral tissue, whereas acetylcholine, carbachol, and angiotensin II had no or only minor contractile effects. The contraction induced by norepinephrine was reversed by the drugs with the following rank order of efficacy: sodium nitroprusside > delquamine > sildenafil > C-type natriuretic peptide > forskolin > acetylcholine. The maximal reversion of tension ranged from 68% (sodium nitroprusside) to 22% (acetylcholine). The relaxing effects of the drugs were paralleled by a several-fold increase in tissue levels of cyclic GMP and cyclic adenosine monophosphate., Conclusion: The results provide evidence that urethral smooth muscle is under the control of endogenous compounds, such as adrenergic agonists (norepinephrine and phenylephrine), vasoactive peptides, prostagladins, NO/cyclic GMP, and acetylcholine, assumed to influence micturition at the peripheral level., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The effects of inhibition of PGF2α synthesis on luteolysis in mares and on the incidence of prolonged luteal activity were studied in controls and in a group treated with flunixin meglumine (FM), a PGF2α inhibitor (n = 6/group). The FM was given every 8 hours (1.0 mg/kg) on each of Days 14.0 to 16.7. Concentration (pg/mL) of PGF2α metabolite averaged over 8 hours of hourly blood sampling at the beginning of each day, was lower in the FM group than in the controls on Day 14 after ovulation (6.7 ± 1.3 vs. 13.8 ± 2.9, P < 0.05), Day 15 (15.0 ± 3.9 vs. 35.2 ± 10.4, P < 0.10), and Day 16 (21.9 ± 5.7 vs. 54.7 ± 11.4, P < 0.03). Concentration (ng/mL) of progesterone (P4) was greater in the FM group than in the controls on Day 14 (10.1 ± 0.9 vs. 7.7 ± 0.9, P < 0.08), Day 15 (9.2 ± 1.0 vs. 4.3 ± 1.0, P < 0.008), and Day 16 (5.6 ± 1.6 vs. 1.2 ± 0.4, P < 0.02). The interval from ovulation to the beginning of a decrease in P4 and to the end of luteolysis (P4 < 1 ng/mL) was each delayed (P < 0.03) by ~1 day in the FM group. Intervals involving the luteal phase were long (statistical outliers, P < 0.05) in two mares in the FM group, indicating prolonged luteal activity. Results supported the hypotheses that (1) inhibition of PGF2α synthesis interferes with luteolysis in mares and (2) inhibition of PGF2α at the expected time of luteolysis may lead to prolonged luteal activity., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The bovine corpus luteum (CL) is a transient gland with a life span of only 18 days in the cyclic cow. Mechanisms controlling CL development and secretory function may involve factors produced both within and outside this gland. Although luteinizing hormone (LH) surge is the main trigger of ovulation and granulosa cells luteinization, many locally produced agents such as arachidonic acid (AA) metabolites, growth factors and cytokines were shown to complement gonadotropins action in the process of CL development. Bovine CL is a highly vascular gland, where the very rapid angiogenesis rate (until Day 5 of the cycle) results in the development of a capillary network, endowing this gland with one of the highest blood flow rate per unit mass in the body. Angiogenesis in the developing CL is later followed by either controlled regression of the microvascular tree in the non-fertile cycle or maintenance and stabilization of the blood vessels, as seen during pregnancy. Different luteal cell types (both steroidogenic and accessory luteal cells: immune cells, endothelial cells, pericytes and fibroblasts) are involved in the pro- and/or anti-angiogenic responses. The balance between pro- and anti-angiogenic responses to the main luteolysin - prostaglandin F2α (PGF2α) could be decisive in whether or not PGF2α induces CL regression. Fibroblast growth factor-2 (FGF2) may be one of the factors that modulate the angiogenic response to PGF2α. Manipulation of local production and action of FGF2 will provide new tools for reproductive management of dairy cattle. Luteolysis is characterized by a rapid decrease in progesterone production, followed by structural regression. Factors like endothelin-1, cytokines (tumour necrosis factorα, interferons) and nitric oxide were all shown to play critical roles in functional and structural regression of the CL by inhibiting steroidogenesis and inducting apoptosis., (© 2013 Blackwell Verlag GmbH.)

There is no distinct explanation of the mechanism for the prepartal prostaglandin F2alpha (PGF2alpha) increase in pregnant dogs. Although the PGF2alpha-synthase (PGFS [AKR1C3]) mRNA expression and localization profiles have been previously investigated in canine utero/placental compartments, the availability and biochemical activity of the PGFS (AKR1C3) protein remain unknown. In order to better understand the regulation of canine uterine PGF2alpha availability and eventual prepartum release in luteolytic amounts in dogs, canine-specific PGFS (AKR1C3) and 15-hydroxyprostaglandin dehydrogenase (HPGD) antibodies were generated and used to characterize the expression, cellular localization, and biochemical properties of PGFS (AKR1C3) and HPGD in the utero/placental compartments and corpus luteum throughout pregnancy and at prepartum luteolysis. PGFS (AKR1C3) expression was weak or absent in luteal samples. Uterine PGFS (AKR1C3) was up-regulated postimplantation and declined prepartum. The utero/placental expression of PGFS (AKR1C3) was identified in the superficial uterine glands throughout gestation and in the trophoblast cells within the feto-maternal contact zone during placentation, suggesting a possible role for PGFS (AKR1C3) in the trophoblast invasion. Utero-placental HPGD was up-regulated until postimplantation, lower at midgestation, and greatly suppressed at prepartum. Expression was routinely identified in the endometrial surface and glandular epithelia, and positive signals were also observed in the trophoblast cells at the feto-maternal contact zone. The biochemical activity of recombinant PGFS (AKR1C3) and HPGD was confirmed after its expression in a heterologous system. The colocalization of HPGD with PGFS (AKR1C3) expression suggests a modulatory role for HPGD as a gatekeeper of the supply of prostaglandin in the pregnant canine uterus.

Human models of headache may contribute to understanding of prostaglandins' role in migraine pathogenesis. The current thesis investigated the migraine triggering effect of prostaglandin E2 (PGE2) in migraine patients without aura, the efficacy of a novel EP4 receptor antagonist, BGC20-1531, in prevention of PGE2-induced headache and the ability of prostaglandin F2α (PGF2α) to trigger headache without any vasodilatation in healthy volunteers. All studies were designed as double-blind, placebo-controlled, cross-over experiments, where PGE2/PGF2α or saline were infused over 20-25 min. In the study with EP4 receptor antagonist healthy volunteers were pre-treated with two different doses of BGC20-1531 or placebo followed by PGE2 infusion over 25 min. The headache data were collected during the whole study day, whereas the possible vascular changes were measured during the in-hospital phase of 1.5 h. The infusion of PGE2 caused the immediate migraine-like attacks and vasodilatation of the middle cerebral artery in migraine patients without aura. The highly specific and potent EP4 receptor antagonist, BGC20-1531, was not able to attenuate PGE2-induced headache and vasodilatation of both intra- and extra-cerebral arteries. The intravenous infusion of PGF2α did not induce headache or statistically significant vasoconstriction of cerebral arteries in healthy volunteers. Novel data on PGE2-provoked immediate migraine-like attacks suggest that PGE2 may be one of the important final products in the pathogenesis of migraine. The lack of efficacy of EP4 receptor antagonist suggests that a single receptor blockade is not sufficient to block PGE2 responses, hence EP2 receptor should be investigated as a potential drug target for the treatment of migraine. The absence of headache during the PGF2α infusion demonstrates that vasodilating properties are necessary for the induction of headache and migraine.

The rapid recent increase in microarray-based gene expression studies in the corpus luteum (CL) utilizing macaque models gathered increasing volume of data in publically accessible microarray expression databases. Examining gene pathways in different functional states of CL may help to understand the factors that control luteal function and hence human fertility. Co-regulation of genes in microarray experiments may imply common transcriptional regulation by sequence-specific DNA-binding transcriptional factors. We have computationally analyzed the transcription factor binding sites (TFBS) in a previously reported macaque luteal microarray gene set (n=15) that are common targets of luteotropin (luteinizing hormone (LH) and human chorionic gonadotropin (hCG)) and luteolysin (prostaglandin (PG) F(2)α). This in silico approach can reveal transcriptional networks that control these important genes which are representative of the interplay between luteotropic and luteolytic factors in the control of luteal function. Our computational analyses revealed 6 matrix families whose binding sites are significantly over-represented in promoters of these genes. The roles of these factors are discussed, which might help to understand the transcriptional regulatory network in the control of luteal function. These factors might be promising experimental targets for investigation of human luteal insufficiency., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Arachidonic acid (AA) is the metabolic precursor to a diverse range of downstream bioactive lipid mediators. A positive or negative influence of individual eicosanoid species [e.g., prostaglandins (PGs), leukotrienes, and hydroxyeicosatetraenoic acids] has been implicated in skeletal muscle cell growth and development. The collective role of AA-derived metabolites in physiological states of skeletal muscle growth/atrophy remains unclear. The present study aimed to determine the direct effect of free AA supplementation and subsequent eicosanoid biosynthesis on skeletal myocyte growth in vitro. C2C12 (mouse) skeletal myocytes induced to differentiate with supplemental AA exhibited dose-dependent increases in the size, myonuclear content, and protein accretion of developing myotubes, independent of changes in cell density or the rate/extent of myogenic differentiation. Nonselective (indomethacin) or cyclooxygenase 2 (COX-2)-selective (NS-398) nonsteroidal anti-inflammatory drugs blunted basal myogenesis, an effect that was amplified in the presence of supplemental free AA substrate. The stimulatory effects of AA persisted in preexisting myotubes via a COX-2-dependent (NS-389-sensitive) pathway, specifically implying dependency on downstream PG biosynthesis. AA-stimulated growth was associated with markedly increased secretion of PGF(2α) and PGE(2); however, incubation of myocytes with PG-rich conditioned medium failed to mimic the effects of direct AA supplementation. In vitro AA supplementation stimulates PG release and skeletal muscle cell hypertrophy via a COX-2-dependent pathway.

Problem: Human labour is an inflammatory process with a heavy infiltration of immune cells into the myometrium and cervix induced by local chemokine production. Myometrial cells also express chemokine receptors, but there is little information about their behaviour or function during pregnancy and labour., Method of Study: We studied the behaviour of the receptors (CCR2, CXCR1 and CXCR2) for the CCL2 and CXCL8 in human myometrium, because both have been shown to be important in labour., Results: We found that there was a significant decline in the mRNA expression of all three receptors in the upper segment and a similar trend in the lower segment with the onset of term labour (TL). Chemokine receptor mRNA expression was increased by stretch, reduced by oxytocin and PGF(2α) acting via phospholipase C (PLC). CXCR2 declined with exposure to CXCL8, consistent with the negative relationship observed in labouring myometrial tissue. The mRNA changes were confirmed by western analysis and flow cytometry., Conclusion: These data show that myometrial chemokine receptor expression is reduced with the onset of term labour probably in response to the increased activity of chemokines, oxytocin and PGF(2α) ., (© 2012 John Wiley & Sons A/S.)

The objective of the study was to evaluate the morphological and functional characteristics of luteal cells isolated from buffalo ovary. Luteal cells exhibited columnar morphology and contact inhibition at the stage of confluence. Protein concentrations increased linearly from Day 3 to Day 7 of culture. DNA concentrations increased from Day 3 to Day 5 and then declined to Day 7 of culture. PGF2alpha concentrations decreased progressively from Day 3 to Day 7 of culture. It was concluded that buffalo luteal cells could serve as an excellent model for studying the specific role of PGF2alpha in maternal recognition of pregnancy and implantation.

We previously showed that prostaglandin F(2α) (PGF(2α)) stimulates the synthesis of interleukin-6 (IL-6), a potent bone resorptive agent, in part via p44/p42 mitogen-activated protein (MAP) kinase and p38 MAP kinase but not stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) among the MAP kinase superfamily in osteoblast-like MC3T3-E1 cells. In the present study, we investigated the involvement of AMP-activated protein kinase (AMPK), an intracellular energy sensor, in PGF(2α)-stimulated IL-6 synthesis in MC3T3-E1 cells. PGF(2α) time-dependently induced the phosphorylation of the AMPK α-subunit. Compound C, an inhibitor of AMPK, dose-dependently suppressed PGF(2α)-stimulated IL-6 release. Compound C reduced the PGF(2α)-induced acetyl-CoA carboxylase phosphorylation. In addition, PGF(2α)-stimulated IL-6 release in human osteoblasts was also inhibited by compound C. The IL-6 mRNA expression induced by PGF(2α) was markedly reduced by compound C. Downregulation of the AMPK α1-subunit by short interfering RNA (siRNA) significantly suppressed the PGF(2α)-stimulated IL-6 release. PGF(2α)-induced phosphorylation of p38 MAP kinase was inhibited by compound C, which failed to affect the p44/p42 MAP kinase phosphorylation. These results strongly suggest that AMPK regulates PGF(2α)-stimulated IL-6 synthesis via p38 MAP kinase in osteoblasts.

A series of experiments were conducted to quantify PGF2α in bovine semen, seminal plasma, and extended semen, and to determine if PGF2α was synthesized or released during extension of bovine semen. Concentrations of PGF2α were measured in paired samples of whole and extended semen from beef and dairy bulls. Concentrations of PGF2α did not differ between beef and dairy (mean±SEM, 273.8±42.8 vs. 210.3±18.5 pg/mL, respectively; P=0.12), but tended (P=0.08) to be greater for whole compared with extended semen (255.5±29.8 vs. 194.5±17.0 pg/mL). Whole semen was extended at eight dilution rates (regardless of initial sperm concentration), using a diluent consisting of two fractions. Samples collected after each dilution step resulted in four subsamples. Concentrations of PGF2α in subsamples decreased (P<0.001) at higher dilution rates and later steps of extension. Subsequently, whole semen and seminal plasma were extended at three dilution rates. Initial PGF2α concentration was greater (P<0.001) for whole semen compared with seminal plasma. During extension, PGF2α synthesis or release resulted in less disparity, but the amount synthesized or released was greater (P=0.03) for semen compared with seminal plasma. We concluded that synthesis or release of PGF2α during extension resulted in concentrations similar to whole semen., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Introduction: Vascular cell adhesion molecule (VCAM-1) plays a critical role in the inflammatory processes by stimulating the recruitment, extravasation, and migration of leukocytes. Its expression and regulation in the dental pulp is not well elucidated., Methods: Primary dental pulp cells were exposed to prostaglandin E(2) (PGE(2)), prostaglandin F(2α) (PGF(2α)), or interleukin 1β (IL-1β) with/without aspirin. VCAM-1 messenger RNA expression was analyzed by reverse transcriptase-polymerase chain reaction. Soluble VCAM-1 (sVCAM-1) in the culture medium was determined by enzyme-linked immunosorbent assay, and the number of viable cells was estimated by (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay., Results: IL-1β induced VCAM-1 gene expression of pulp cells. IL-1β also stimulated sVCAM-1 production. The IL-1β-induced sVCAM-1 production was not inhibited but rather enhanced by aspirin, a cyclooxygenase (COX) inhibitor. PGE(2) and PGF(2α) decreased the VCAM-1 expression and sVCAM-1 production of pulp cells. U0126 (1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthio]butadiene), a mitogen-activated protein kinase kinase (MEK) inhibitor, attenuated IL-1β-induced sVCAM-1 production. However, no marked cytotoxicity was noted in these experimental conditions as analyzed by MTT assay., Conclusions: IL-1β may be involved in the pulpal inflammatory processes via stimulation of VCAM-1 expression and sVCAM-1 production. This event is not mediated by COX activation and prostanoid production but is associated with MEK signaling. PGE(2) and PGF(2α) may potentially regulate inflammatory processes by the inhibition of VCAM-1., (Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Accumulation of collagen I and III in the myocardium is a prominent feature of interstitial fibrosis. Prostaglandin F(2α) (PGF(2α)) facilitates fibrosis by increasing collagen synthesis. However, the underlying mechanisms mediating the effect of PGF(2α) on collagen expression in cardiac fibroblasts are not yet fully elucidated. We measured the mRNA and protein levels of collagen I and III by quantitative real-time PCR and ELISA, respectively. Activation of signaling pathways was determined by western blot analysis. In primary rat cardiac fibroblasts, treatment with PGF(2α) stimulated both the mRNA and protein levels of collagen I and III, and pretreatment with the F-prostanoid (FP) receptor antagonist AL-8810, protein kinase C inhibitor LY-333531, and Rho kinase inhibitor Y-27632 significantly inhibited PGF(2α)-induced collagen I and III expression. FP receptor, protein kinase C, and Rho kinase were activated with PGF(2α) treatment. PGF(2α) may be an important regulator in the synthesis of collagen I and III via an FP receptor/protein kinase C/Rho kinase cascade in cardiac fibroblasts, which might be a new therapeutic target for myocardial fibrosis., (Published by Elsevier Ltd.)

Recent findings on the luteolytic process in mares are reviewed and differences from other farm species are noted. It is well known that the luteolysin, PGF2α (PGF), is secreted from the endometrium in the absence of pregnancy in farm animal species. But PGF is a potent chemical and safeguards have evolved so that only the corpus luteum (CL) is affected. The safeguards include a short PGF half-life and secretion in two or three pulses per day. In mares, endogenous PGF travels from the uterus to the CL through the systemic circulation, but the luteal-cell membranes are highly efficient in capturing the PGF molecules. In ruminants, luteal affinity is lower, but an efficient pathway has evolved for local delivery of PGF from a uterine horn to the adjacent ovary. The beginning of transition from luteal control is manifested within 1 h in mares and heifers, as indicated by a dynamic change in systemic progesterone concentrations. In mares, the transition into luteolysis begins during a relatively small transitional pulse of PGFM (a PGF metabolite) and oxytocin increases with the PGFM pulse. During luteolysis, estradiol increases in stepwise fashion within the hours of each PGFM pulse, with a plateau between pulses. Progesterone decreases linearly within the hours of a PGFM pulse and continuing during the interval between pulses, whereas luteal blood flow decreases during the declining portion of the pulse. In contrast, in heifers, progesterone decreases and increases within the hours of a PGFM pulse, and luteal blood flow increases and decreases concomitantly with the pulse., (Copyright © 2012 Elsevier Inc. All rights reserved.)

To advance the understanding of early pregnancy and pregnancy failure in horses, this study determined how luteolysis induced by cloprostenol (an analogue of prostaglandin F2α) affects conceptus development. Mares were injected on Days 12, 14, 16 or 18 of pregnancy with either cloprostenol (treatment groups, total n=83 pregnancies) or saline (controls, n=81), and growth of the conceptuses was monitored and compared by daily ultrasonography until they were collected transcervically on Days 15-22, 1-4 days after the injections. The comparisons were extended in the recovered conceptuses by counting somites, measuring the volume and osmolality of yolk-sac fluid and its concentrations of proteins, estrone sulfate and progesterone, and by assessing the morphology of the capsule and vascular system. When luteolysis was initiated on or before Day 16, most pregnancies survived until the time of collection and the conceptuses in respective treated and control groups on Days 15-20 were very similar except for some effects of treatment on the capsule and vascular development. In contrast, after luteolysis was initiated on Day 18, abortion often ensued within 3 days and most conceptuses collected had degenerated, therein constituting a predictable system in which to study the pathogenesis of a particular cause of pregnancy failure.

Maternal recognition of pregnancy in the horse is the sum of events leading to maintenance of pregnancy; in a narrow sense, maternal recognition of pregnancy refers to the physiological process by which the lifespan of the corpus luteum is prolonged. The horse is one of the few domestic species in which the conceptus-derived pregnancy recognition signal has not been identified. The presence of the conceptus reduces pulsatile prostaglandin F(2α) secretion by the endometrium during early gestation in the mare, partly attributed to the reduced expression of cyclooxygenase-2. Cyclooxygenase-2 has therefore been suggested as one of the regulators of endometrial prostaglandin F(2α) release modified by the antiluteolytic factor secreted by the conceptus. In addition, altered oxytocin responsiveness has been implicated in the adjustment of prostaglandin release in pregnant mares. While conceptus mobility has proven to be essential for establishment of pregnancy, conceptus-derived oestrogens and prostaglandins, principally prostaglandin E(2), have not been confirmed as the critical antiluteolytic factor. Various ways to induce prolonged luteal function in the non-pregnant mare will be highlighted in the current review, specifically, how they may pertain to the process of maternal recognition of pregnancy. Furthermore, recently published microarray experiments comparing the transcriptome of pregnant and non-pregnant endometria and different stages of conceptus development will be reviewed. Findings include the prevention of conceptus adhesion, the provision of nutrients to the conceptus and the avoidance of immunological rejection, among others.

Objective: Preeclampsia is characterized by hypertension and proteinuria developing after 20 weeks of gestation. Increased vasoconstriction can be one of the major underlying pathophysiological event in this syndrome. We examined the role of vasoconstrictor prostanoid, prostaglandin F2α (PGF2α) in preeclamptic and normotensive human umbilical veins., Methods: Umbilical veins were set up in organ bath. The concentration-response curves of PGF2α (endogenous agonist of prostaglandin F receptor) and fluprostenol (prostaglandin F receptor selective agonist) were determined in normal and preeclamptic veins either in the absence or presence of BAY u3405 (thromboxane A2 receptor selective antagonist). PGF2α and its major metabolite concentrations were measured by enzyme immunoassay kit. The expression of vasoconstrictor prostanoid receptors was determined by western blot., Results: The concentration-dependent contractions to PGF2α and fluprostenol were significantly increased in umbilical vein preparations derived from preeclamptic women compared with those of normotensives. Increased reactivity was related with enhanced sensitivity to these spasmogens in preeclamptic veins. BAY u3405 (10 μmol/l) did not modify the responsiveness to PGF2α in normal umbilical veins whereas moderately reduced the contractions in preeclamptic preparations. Serum concentrations of PGF2α and its major metabolite, 13,14-dihydro-15-keto-PGF2α, were comparable between preeclamptics and normotensives whereas the metabolite concentration was elevated in umbilical cord serum of preeclamptics. 13,14-dihydro-15-keto-PGF2α, release was also increased in umbilical vein preparations of preeclamptic women. An increased prostaglandin F receptor protein expression was determined whereas EP3 and thromboxane A2 protein expressions were unchanged in preeclamptic umbilical veins., Conclusion: Prostaglandin F and thromboxane A2 receptors activation by PGF2α could be involved in umbilical vasospasm observed in preeclampsia.

The dynamic expression for estrogen receptor subtype-1 (ESR1), interleukin-1beta (IL1B), and apoptosis-associated genes, as well as nitric oxide synthase activity, were examined in corpora lutea (CL) of rabbits after prostaglandin F(2alpha) (PGF(2alpha)) administration on either day 4 or day 9 of pseudopregnancy. By reverse transcriptase polymerase chain reaction, the steady-state level of ESR1 transcript was lower (P < 0.01) and that of anti-apoptotic B-cell CLL/lymphoma 2 (BCL2) -like 1 (BCL2L1) was greater in day 4 (P < 0.01) than in day 9 CL. Western blot analysis revealed that BCL2-associated X protein (BAX) abundance was greater in day 4 (P < 0.01) than in day 9 CL, whereas BCL2L1 protein was undetectable at both luteal stages. After PGF(2alpha), ESR1 transcript decreased (P < 0.01) in day 9 CL, whereas IL1B mRNA showed a transitory increase (P < 0.01) at both stages. The pro-apoptotic tumor protein p53 (TP53) gene had diminished (P < 0.01) on day 4 and on day 9 after a transitory increase (P < 0.01), whereas the BAX/BCL2L1 expression ratio increased (P < 0.01) in day 9 CL 24 h after treatment. Following PGF(2alpha), TP53 protein increased (P < 0.01) at both luteal stages, and BAX decreased (P < 0.01) in day 4 CL but increased (P < 0.01) 24 h later in day 9 CL; BCL2L1 became detectable 6 h later in day 4 CL. Nitric oxide synthase activity temporarily increased (P < 0.01) following PGF(2alpha). These findings suggest that PGF(2alpha) regulates luteolysis by ESR1 mRNA down-regulation and modulation of pro- and anti-apoptotic pathways in CL that have acquired a luteolytic capacity., (Copyright 2010 Elsevier Inc. All rights reserved.)

Objective: To investigate the involvement of 8-iso-PGF(2alpha) and 25-hydroxycholesterol (25-OH-Chol) in the pathophysiology of endometriosis., Design: Observational case-control study using enzyme immunoassay and high-performance liquid chromatography (HPLC)., Setting: Postgraduate Institute of Medical Education and Research., Patient(s): Forty-five women undergoing laparoscopy (n = 25), laparotomy (n = 19), or tubal ligation (n =1)., Intervention(s): Venipuncture and laparoscopic peritoneal fluid (PF) collection., Main Outcome Measure(s): The levels of 8-iso-PGF(2alpha) were determined both in urine and PF of all the patients using enzyme immunoassay. The levels of 25-OH-Chol were determined by using reversed phase HPLC both in the plasma and PF samples. Oxidative damage to DNA was assessed by agarose gel electrophoresis., Result(s): Significantly increased levels of 8-iso-PGF(2alpha) were observed both in urine and PF of women with endometriosis compared with control women. Similarly, higher levels of 25-OH-Chol were observed both in plasma and PF of patients compared with controls and the difference was statistically significant. A clear-cut tailing pattern was observed in DNA of patients with endometriosis, indicating significant DNA damage., Conclusion(s): Our observations implicate oxidative stress in the pathophysiology of endometriosis. For the first time, we demonstrate that 8-iso-PGF(2alpha) and oxysterols (the known promoters of steroidogenesis) might be the culprits in this disease., (Copyright (c) 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

The essential role of endometrial prostaglandin F2 alpha (PTGF) for induction of the corpus luteum (CL) regression is well documented in the cow. However, the acute effects of PTGF on known local luteotropic factors (oxytocin [OXT] and its receptor, insulin-like growth factor [IGF] 1, and progesterone and its receptor), the principal angiogenic factor vascular endothelial growth factor (VEGF) A and the capillary destabilization factor angiopoietin (ANGPT) 2 were not thoroughly studied in detail. The aim of this study was therefore to evaluate the tissue concentration of these factors during PTGF induced luteolysis. In addition the mRNA expression of progesterone receptor (PGR), OXT receptor (OXTR), IGF1, IGFBP1, ANGPT1, and ANGPT2 was determined at different times after PTGF treatment. Cows (n = 5 per group) in the mid-luteal phase (Days 8-12, control group) were injected with the PTGF analog (cloprostenol), and CL were collected by transvaginal ovariectomy at 0.5, 2, 4, 12, 24, 48, and 64 h after injection. The mRNA expression was analyzed by quantitative real-time PCR, and the protein concentration was evaluated by enzyme immunoassay or radioimmunoassay. Progesterone concentrations, as well as mRNA expression of PGR, in CL tissue were significantly down-regulated by 12 h after PTGF. Tissue OXT peptide and OXTR mRNA decreased significantly after 2 h, followed by a continuous decrease of OXT mRNA. IGF1 and VEGFA protein already decreased after 0.5 h. By contrast, the IGFBP1 mRNA was up-regulated significantly after 2 h to a high plateau. ANGPT2 protein and mRNA significantly increased during the first 2 h, followed by a steep decrease after 4 h. The acute decrease of local luteotropic activity and acute changes of ANGPT2 and VEGFA suggest that modulation of vascular stability may be a key component in the cascade of events leading to functional luteolysis.

To address the potential luteolytic role for prostaglandin F(2 alpha) (PGF(2 alpha)) in the corpus luteum of the common marmoset monkey (Callithrix jacchus), the ability of marmoset luteal cells, maintained in monolayer culture, to produce PGF(2 alpha) was determined in vitro in the presence and absence of human chorionic gonadotrophin (hCG) and other established pharmacological modulators of PGF(2 alpha) synthesis. We also assessed the effects of the PGF(2 alpha) analogue, cloprostenol, on progesterone output from luteal cells isolated in the early luteal phase versus the mid-luteal phase (days 3 and 14 post ovulation, respectively). Cloprostenol had no effect on progesterone output from luteal cells isolated on day 3 of the luteal phase, whereas it significantly inhibited both basal and hCG-stimulated progesterone synthesis by day 14 luteal cells during the culture period 48-72 h (P<0.001). Intra-luteal PGF(2 alpha) concentrations were 5-fold higher in luteal cells isolated in the early luteal phase than in mid-luteal phase cells (16.5+/-3.5 versus 3.5+/-0.6 pmol/10(5) cells). While PGF(2 alpha) production was unaffected by hCG in vitro, it was decreased by indomethacin (1000 ng/ml) (P<0.05) and stimulated by the calcium ionophore A23187 (10 micromol/l) (P<0.05) in luteal cells from both stages of the luteal phase. Phospholipase A(2) did not influence PGF(2 alpha) production by day 3 luteal cells whereas at 10 IU/ml, it significantly stimulated PGF(2 alpha) production by day 14 luteal cells (P<0.05). Hence, the timing of luteolysis in the common marmoset monkey appears to involve changes in both the luteal cell response to and production of PGF(2 alpha)., ((c) 2010 Elsevier Inc. All rights reserved.)

The corpus luteum (CL) of the estrous cycle in the cow is a dynamic organ which has a lifespan of approximately 17-18 days. The main function of the CL is to produce progesterone (P) that requires for achievement and maintenance of pregnancy. If pregnancy does not occur successfully, the CL must regress within a few days to induce the next chance of ovulation. As the CL matures, the steroidogenic cells establish contact with many capillary vessels, consequently the CL is composed of a large number of vascular endothelial cells that can account for up to 50% of all cells. Therefore, blood vessels and blood flow within the CL have an essential role in luteal function. Nitric oxide (NO), a strong vasorelaxant, is now known to play key roles in a variety of physiological process. Indeed, NO has established itself as a polyvalent molecule which plays a decisive role in regulating multiple functions within female reproductive system. In the CL, NO is produced and regulates luteal blood flow, P secretion and apoptosis of luteal cells as well as endothelial cells. This review describes the current investigation for possible roles of NO in the luteolytic cascade within the bovine CL.

The present review focuses primarily on the studies we made in recent years to improve the understanding of the molecular mechanisms of PGF2alpha-induced hypertrophy of Vascular Smooth Muscle Cells (VSMC). In this review, we will summarize the recent findings in the context of the PGF2alpha signaling pathway in three parts: PGF2alpha binding to its receptor, transactivation of EGF receptor, two independent signaling transduction pathways increasing the expression of NOX1 gene.

Thirty to 40% of pregnancies are lost during the first third of pregnancy, which has been hypothesized to be due to inadequate progesterone secretion by the corpus luteum. Loss of luteal progesterone secretion during the estrous cycle is via uterine secretion of prostaglandin F(2)alpha (PGF(2)alpha). Cow luteal tissue secretion of prostaglandins (PG) E (PGE(1)+PGE(2)) and PGF(2)alpha are derived from precursors in membrane phospholipids. Cow luteal tissue secretion of PGE and PGF(2)alpha increased linearly with time in culture with the PGE: ratio being 1:1. PGE(1) or PGE(2) are luteotropic in cows and ewes and antiluteolytic in vitro and in vivo in ewes. Endocannabinoids are also derived from phospholipids and are associated with infertility, presumably by reducing implantation; however, effects of endocannabinoids on luteal function have not been addressed. The objective of this experiment was to determine the effects of endocannabinoid type 1 and 2 receptor agonists and receptor antagonists or a fatty acid amide hydrolase (FAAH; catabolizes endocannabinoids) inhibitor, PGE(1), or PGF(2)alpha on bovine luteal secretion of progesterone, PGE, and PGF(2)alphain vitro. PGE and PGF(2)alpha was increased (P< or =0.05) with time in culture, while progesterone did not change (P> or =0.05) with time in vehicle-treated luteal slices in vitro. Progesterone was increased (P< or =0.05) by PGE(1) and decreased (P< or =0.05) by PGF(2)alpha, CB(1) or CB(2) receptor agonists, or a FAAH inhibitor. Both PGE and PGF(2)alpha were decreased (P< or =0.05) by CB(1) or CB(2) receptor agonists or a FAAH inhibitor when compared to vehicle controls. It is concluded that endocannabinoid receptor agonists negatively affect cow luteal function in vitro and that the corpus luteum may also be a site for endocannabinoid decreased fertility as well as a reduction in implantation.

The corpus luteum (CL) of the estrous cycle in the cow is a dynamic organ which has a life time of approximately 17-18 days. The main function of the CL is to secrete a large amount of progesterone (P) thereby supporting the achievement of pregnancy. As the CL matures, the steroidogenic cells establish contact with many capillaries and the matured CL is composed of many vascular endothelial cells that account for up to 50% of all CL cells. The bovine CL produces several major angiogenic and vasoactive foctors such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), angiopoietin-1 and -2 (ANPT-1 and -2), prostaglandin F(2alpha) (PGF(2alpha)), endothelin-1 (EDN1), angiotensin II (Ang II) and nitric oxide (NO). These factors regulate P secretion directly and/or indirectly within the CL. Moreover, different actions of PGF(2alpha) in the early cycle CL (non-luteolytic) and the mid cycle CL (luteolytic) may provide insight into the luteolysis cascade in the cow. The aim of the present review is to describe the current concepts of the local mechanisms for the cascade of development and regression of the bovine CL as regulated by luteal angiogenic and vasoactive factors.

Little is known about prostaglandin F(2alpha) in cardiovascular homeostasis. Prostaglandin F(2alpha) dose-dependently elevates blood pressure in WT mice via activation of the F prostanoid (FP) receptor. The FP is expressed in preglomerular arterioles, renal collecting ducts, and the hypothalamus. Deletion of the FP reduces blood pressure, coincident with a reduction in plasma renin concentration, angiotensin, and aldosterone, despite a compensatory up-regulation of AT1 receptors and an augmented hypertensive response to infused angiotensin II. Plasma and urinary osmolality are decreased in FP KOs that exhibit mild polyuria and polydipsia. Atherogenesis is retarded by deletion of the FP, despite the absence of detectable receptor expression in aorta or in atherosclerotic lesions in Ldlr KOs. Although vascular TNF(alpha), inducible nitric oxide enzyme and TGF(beta) are reduced and lesional macrophages are depleted in the FP/Ldlr double KOs, this result reflects the reduction in lesion burden, as the FP is not expressed on macrophages and its deletion does not alter macrophage cytokine generation. Blockade of the FP offers an approach to the treatment of hypertension and its attendant systemic vascular disease.

To study the effect of bacteria in the uterus on the fate of the corpus luteum (CL), Arcanobacterium pyogenes was inoculated into the uteri of cows on Day 3 (Day 0=day of spontaneous ovulation). Plasma concentrations of 13,14-dihydro-15-keto-PGF(2alpha) (PGFM), 13,14-dihydro-15-keto-PGE(2) (PGEM) and progesterone (P(4)) were determined. In five cows, the developing CL regressed and first-wave dominant follicles, which normally become atretic, ovulated (Group OV) after bacterial inoculation. In another five cows (Group NOV) and five control cows, the developing CL did not regress and first-wave dominant follicles did not ovulate. In Group OV, PGFM concentrations increased by 126.2pg/mL (from 36.8+/-7.8pg/mL on Day 3 to 163+/-37.2pg/mL on Day 6), with an increase ratio of 5.8-fold. Conversely, in Group NOV, PGFM had a greater increase of 198.4pg/mL (from 128.2+/-27.8pg/mL on Day 3 to 326.6+/-115.1pg/mL on Day 5), but the increase ratio was only 2.3-fold. Although PGEM tended to increase in both groups, raw increases and increase ratios were small. Bacterial inoculation into the uterus stimulated the release of prostaglandins and affected the fate of the CL; in that regard, the CL was affected more by PGF(2alpha) than by PGE(2), and the increase ratio of PGF(2alpha) was more important than the raw increase.

Purpose: To determine whether a topically instilled prostaglandin analogue inhibits endothelin-1 (ET-1)-induced vasoconstrictive effects in the posterior retina by its local effects, and the duration of the effect in normal rabbit eyes., Methods: Travoprost, a potent selective FP-agonist, or unoprostone, a prostone that also has a weak non-selective FP-agonistic activity, solution was instilled once, or once daily (travoprost) or twice daily (unoprostone) for 7 days in one randomly chosen Dutch rabbit eye, and vehicle in the contralateral eye. ET-1 was intravitreously injected in both eyes 30 min after a single instillation of a test drug or its vehicle, or just after, 30, 60, 90 or 180 min after the final instillation of a 7-day instillation, and fundus photographed before, 30 and 60 min after the injection to study whether difference was seen in the ET-1-induced constriction of retinal vessels between the drug- and vehicle-instilled eyes. The same experimental procedures were conducted with indomethacin pretreatment., Results: In the rabbit eyes where travoprost was instilled for 7 days, the ET-1-induced constriction of retinal vessels was significantly inhibited only on the drug-treated side, when ET-1 was injected 30 or 60 min after the final instillation (P = 0.026-0.005), which was abolished by indomethacin pretreatment. A single instillation of travoprost or unoprostone and 7-day instillation of unoprostone showed no effect., Conclusions: After a 7-day instillation in normal rabbit eyes, topical travoprost suppressed ET-1-induced vasoconstrictive effects only in the ipsilateral posterior retina by its local effect; this effect was maintained at least for 30 min and mediated by endogenous prostaglandins.

Prostaglandins are primary mediators of pain and are involved in pathological conditions such as hypertension, cancer and inflammation but are also needed for normal function of the female reproductive system. This may hold true for other systems because long term use of selective COX-2 inhibitors such as VIOXX and BEXTRA was associated with heart failure, leading to their withdrawal. A thorough study of the contribution of prostaglandins in the regulation of normal body function is clearly needed. A major drawback of the current therapeutic strategies aiming at controlling PGs is that they aim at early steps of biosynthesis thus blocking all PGs, good and bad. However, PGs often work as opposing dyads such as PGI2-TXA2 in the vascular system and PGF2alpha-PGE2 in the female reproductive system. The paradigm thus appears as effecting selective synthesis, transport and action of individual PG isoforms. In this respect, the female reproductive system appears as an ideal study model. Data from human and animal genome projects allowed identifying the corresponding members of the biosynthetic and signal transduction components of the PG system in different animal species. Of particular interest was that PG terminal synthase shared similarities or identity with enzymes previously known for steroid or sugar metabolism and free radical detoxification. We present here an integrated view of PG action based on observations in the female reproductive system, but with potential strategic implications for cardiovascular and metabolic complications.

The main function of the corpus luteum (CL) is production of progesterone (P4). Adequate luteal function to secrete P4 is crucial for determining the physiological duration of the oestrous cycle and for achieving a successful pregnancy. The bovine CL grows very fast and regresses within a few days at luteolysis. Mechanisms controlling development and secretory function of the bovine CL may involve many factors that are produced both within and outside the CL. Some of these regulators seem to be prostaglandins (PGs), oxytocin, growth and adrenergic factors. Moreover, there is evidence that P4 acts within the CL as an autocrine or paracrine regulator. Each of these factors may act on the CL independently or may modify the actions of others. Although uterine PGF(2 alpha) is known to be a principal luteolytic factor, its direct action on the CL is mediated by local factors: cytokines, endothelin-1, nitric oxide. The changes in ovarian blood flow have also been suggested to have some role in regulation of CL development, maintenance and regression.

There is an increasing body of evidence that prostanoids modulate mast cell functions and contribute to the development of allergic inflammation. The present study aimed to identify an undetermined function of prostaglandin (PG) F(2alpha) in mast cell activation and the signaling mechanism involved in it. Simultaneous quantification of prostanoids by liquid chromatography/tandem mass spectrometry revealed the constitutive release of PGF(2alpha), thromboxane B(2), and 6-keto-PGF(1alpha) from bone marrow-derived mast cells (BMMCs). Upon activation of BMMCs by lipopolysaccharide, the cytokine production in BMMCs was enhanced when the culture was supplemented with PGF(2alpha). However, F prostanoid receptor-a selective receptor for PGF(2alpha)-was not detected in BMMCs. Further investigations performed using prostanoid receptor antagonists revealed an alternative mechanism wherein the receptors for PGE species-E prostanoid receptors-mediated the PGF(2alpha) signal in BMMCs. The present study provides an insight into a novel function of PGF(2alpha), i.e., an autocrine accelerator for mast cell activation.

Background: Exhaled nitric oxide and induced sputum eosinophils are well established as direct markers of inflammation/oxidative stress in asthma. Recently, it has been proposed that sputum 8-isoprostane concentrations may present a reliable index for measuring oxidative stress in asthmatic patients. We assessed the value of sputum 8-isoprostane in mild asthma in children and adolescents., Methods: Patients with newly diagnosed asthma (children, n = 23; adults, n = 14) and age-matched healthy controls (children, n = 13; adults, n = 15) were studied. Lung function was measured by spirometry, sputum was induced by hypertonic saline, and fractional exhaled nitric oxide (FeNO) was measured with standard methods. Cell differential counts were obtained from sputum slides and the concentration of 8-isoprostane was measured with an enzyme immunoassay from sputum supernatants., Results: High-quality sputum specimens could be obtained from 10 children and 10 adults, and the sputum analyses were conducted only for the representative specimens. Asthmatics had increased FeNO (children 35.5 vs. 11.9 ppb; adults 81.1 vs. 16.6 ppb; p < 0.001) and sputum eosinophils (children 2.4% vs. 1.4%; adults 10.4% vs. 0.2%; p = 0.005) compared to healthy controls. There was a significant correlation between FeNO and eosinophils (R = 0.65; p < 0.0001). Sputum 8-isoprostane was not elevated in asthmatics compared to healthy subjects (children 81.1 vs. 89.9 and adults 76.9 vs. 73.4 pg/mL) and did not correlate with lung function or other measurements of airway inflammation. However, increased 8-isoprostane levels were detected in patients with chronic obstructive pulmonary disease (n = 11, 184.7 pg/mL, used as controls for assays)., Conclusions: In agreement with earlier studies, FeNo is sensitive in detecting oxidative/nitrosative stress in asthmatic airways. However, our results suggest that 8-isoprostane may not be sensitive in reflecting oxidant burden in mild asthma.

Knowing how mutations disrupt the interplay between atrioventricular valve (AVV) morphogenesis and function is crucial for understanding how congenital valve defects arise. Here, we use high-speed fluorescence microscopy to investigate AVV morphogenesis in zebrafish at cellular resolution. We find that valve leaflets form directly through a process of invagination, rather than first forming endocardial cushions. There are three phases of valve function in embryonic development. First, the atrioventricular canal (AVC) is closed by the mechanical action of the myocardium, rolls together and then relaxes. The growing valve leaflets serve to block the canal during the roll and, depending on the developmental stage, either expand or hang down as a leaflet to block the canal. These steps are disrupted by the subtle morphological changes that result from inhibiting ErbB-, TGFbeta-or Cox2 (Ptgs2)-dependent signaling. Cox2 inhibition affects valve development due to its effect on myocardial cell size and shape, which changes the morphology of the ventricle and alters valve geometry. Thus, different signaling pathways regulate distinct aspects of the behavior of individual cells during valve morphogenesis, thereby influencing specific facets of valve function.

A critical analysis of the results of research in the function of the endometrium was carried out and a view point presented. The role of the endometrium in endocrine regulation of the oestrus cycle can be summarized as follows: 1. The transfer of prostaglandin F(2alpha) (PGF(2alpha)) from the uterus to an ovary, which causes luteolysis, occurs mainly via the lymphatic pathways. 2. The system of retrograde transfer of PGs enables PGF(2alpha) and PGE(2) to reach the myometrium and endometrium with arterial blood at high concentration. In the luteal phase, PGF(2alpha), together with the increasing concentration of progesterone, constricts the arterial vessels of the uterus; in the follicular phase and in early pregnancy, PGE(2) together with oestrogen and embryonic signals, relaxes the arterial vessels. In addition, this system protects the corpus luteum from premature luteolysis during the cycle and luteolysis during early pregnancy. 3. In days 10-12 of the cycle, the blood flow in the uterus decreases by 60-70% in pigs and around 90% in sheep. This causes ischaemia and local hypoxia confirmed by the presence of hypoxia inducible factor and thus remodelling of the endometrium commences. 4. The pulsatile elevations in PGF(2alpha) concentration occurring in the blood flowing out of the uterus during the period of luteolysis and the next few days, do not result from increased PGF(2alpha) synthesis as suggested in numerous studies. They are the effect of excretion of PGF(2alpha) and its metabolites together with lymph and venous blood and tissue fluids in which prostaglandin accumulates.

Prostaglandin F2alpha (PGF2alpha) increases reactive oxygen species (ROS) and induces vascular smooth muscle cell (VSMC) hypertrophy by largely unknown mechanism(s). To investigate the signaling events governing PGF2alpha-induced VSMC hypertrophy we examined the ability of the PGF2alpha analog, fluprostenol to elicit phosphorylation of Akt, the mammalian target of rapamycin (mTOR), ribosomal protein S6 kinase (p70S6k), glycogen synthase kinase-3beta (GSK-3beta), phosphatase and tensin homolog (PTEN), extracellular signal-regulated kinase 1/2 (ERK1/2) and Jun N-terminal kinase (JNK) in growth arrested A7r5 VSMC. Fluprostenol-induced hypertrophy was associated with increased ROS, mTOR translocation from the nucleus to the cytoplasm, along with Akt, mTOR, GSK-3beta, PTEN and ERK1/2 but not JNK phosphorylation. Whereas inhibition of phosphatidylinositol 3-kinase (PI3K) by LY-294002 blocked fluprostenol-induced changes in total protein content, pre-treatment with rapamycin or with the MEK1/2 inhibitor U0126 did not. Taken together, these findings suggest that fluprostenol-induced changes in A7r5 hypertrophy involve mTOR translocation and occur through PI3K-dependent mechanisms.

Objectives: Cardiovascular diseases are the most common cause of death in the world. Oxidative stress has been proved to play a role in atherosclerotic diseases and 8-isoprostane is one of the most valid markers of in-vivo oxidative stress. We aimed to investigate the 8-isoprostane levels in relation to surrogate and direct angiographic indexes of atherosclerosis., Methods: Urinary 8-isoprostane levels were measured and a B-mode carotid ultrasound examination was performed in 100 consecutive patients scheduled for coronary angiography., Results: In patients with angiographic coronary artery disease (CAD) urinary 8-isoprostane levels were significantly (P<0.001) higher than in patients without CAD (68.75+/-5.5 vs. 38.27+/-3.7 pg/ml). Moreover, 8-isoprostane levels of patients with increased carotid intima media thickness (CIMT) were higher (P<0.001) than in patients with normal CIMT values (75.12+/-6.4 vs. 38.72+/-2.7 pg/ml). Moreover log(8-isoprostane) levels were significantly correlated with maximum and mean CIMT values (P<0.001) and across univessel and multivessel CAD groups levels of log(8-isoprostane) showed a significantly (P<0.001) increasing trend. Logistic regression analysis revealed that 8-isoprostane levels were an independent predictor for both intima-media thickening and angiographic CAD., Conclusion: These findings indicate that elevated urinary levels of 8-isoprostane are associated with both subclinical atherosclerosis and manifest CAD. The results therefore support the hypothesis that isoprostanes-related oxidative stress is involved in the whole atherosclerotic process.