PGF2α Levels Research Articles

Evaluation of oxidative stress markers in first trimester for assessment of preeclampsia risk

The aim of this study is to determine the predictive values of oxidative stress markers and antioxidants in the development of preeclampsia between 10-14 and also at 20-24 weeks of gestation, after the completion of vascular transformation. Levels of oxidative stress parameters such as malondialdehyde (MDA), lipidhydroperoxide (LHP) and prostaglandin F(2α) (PGF(2α)), oxidized LDL (oxLDL), and antioxidant status parameters such as paraoxonase 1 (PON1), superoxide dismutase (SOD) and total antioxidant capacity (TAC) levels were measured and compared in 21 preeclamptic and 24 healthy pregnant women. In preeclamptic women, both between 10-14 and also at 20-24 weeks of gestation the levels of oxLDL, MDA and PGF(2α) were significantly higher (P < 0.001, P < 0.001, respectively), PON1, SOD and TAC were significantly lower (P < 0.01, P < 0.001, P < 0.05, respectively) compared to healthy pregnant women; yet there was no significant difference in LHP levels. Increased levels of serum MDA and PGF(2α), low levels of SOD and PON1 activity, in 10-14 GW may have been associated with preeclampsia etiology. High levels of MDA and PGF(2α) indicate that the oxidative damage is present well before the clinical symptoms occur. A panel of oxidative stress markers such as MDA and PGF(2α) in maternal blood can predict the development of preeclampsia long before clinical onset.

Cyclooxygenase-2 Deficiency Attenuates Adipose Tissue Differentiation and Inflammation in Mice

Obesity is associated with a variety of disorders and is a significant health problem in developed countries. One factor controlling the level of adiposity is the differentiation of cells into adipocytes. Adipocyte differentiation requires expression of peroxisome proliferator-activated receptor γ (PPARγ), which is activated by ligands to regulate expression of genes involved in adipocyte differentiation. Although 15-deoxy-Δ(12,14)-prostaglandin (PG) J(2) (15d-PGJ(2)) has long been known to be a potent activator of PPARγ, the importance of its synthesis in adipose tissue in vivo is not clear. The current study utilized mice deficient in cyclooxygenase-2 (COX-2) to examine the role of COX-2-derived PGs as in vivo modulators of adiposity. As compared with strain- and age-matched wild-type controls, the genetic deficiency of COX-2 resulted in a significant reduction in total body weight and percent body fat. Although there were no significant differences in food consumption between groups, COX-2-deficient mice showed increased metabolic activity. Epididymal adipose tissue from wild-type mice produced a significantly greater level of 15d-PGJ(2), as compared with adipose tissue isolated from mice deficient in COX-2. Furthermore, production of the precursor required for 15d-PGJ(2) formation, PGD(2), was also significantly reduced in COX-2-deficient adipose tissue. The expression of markers for differentiated adipocytes was significantly reduced in adipose tissue from COX-2-deficient mice, whereas preadipocyte marker expression was increased. Macrophage-dependent inflammation was also significantly reduced in adipose tissue of COX-2-deficient mice. These findings suggest that reduced adiposity in COX-2-deficient mice results from attenuated PPARγ ligand production and adipocyte differentiation.

Maternal Levels of Prostacyclin, Thromboxane, ICAM, and VCAM in Normal and Preeclamptic Pregnancies

To evaluate whether impaired endothelial function and endothelial inflammatory response occur in parallel in the women with preeclampsia. Venous blood was drawn from normal (n=40) and severe preeclamptic (sPE) (n=40) pregnant women when they were admitted to the L&D Unit and 24 hrs after delivery. Plasma and serum samples were extracted and measured for 6-keto PGF1α and TXB(2) (stable metabolites of PGI2 and TXA2), and intercellular adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM) by ELISA. Data are analyzed by Mann-Whitney test and paired t-test. The statistical significance is set as P<0.05. Results Plasma 6-keto PGF1α levels were significantly reduced at admission and 24hr after delivery in sPE compared to normal pregnant controls, P<0.01. The ratio of 6-keto PGF1α and TXB(2) was significant less in sPE than that in normal pregnant controls before delivery. There was no significant difference for ICAM and VCAM levels between normal and patients with sPE before and after delivery. Maternal 6-keto PGF1α levels and the ratio of 6-keto PGF1α and TXB(2) were decreased in patients with sPE compared to normal pregnant controls. In contrast, maternal ICAM and VCAM levels were not different between the two groups. These data suggest that serum ICAM and VCAM levels may not be sensitive inflammatory biomarkers for preeclampsia.

Plaque regression in one artery is not necessarily associated with parallel changes in other vascular beds

It remains unclear whether atherosclerosis in one vascular bed progresses in parallel with that in other vascular beds. We investigated serial changes in vessel wall areas (VWAs) in various vessels over 2 years of follow-up. Vessel wall areas in the thoracic descending aorta (TDA), common carotid artery (CCA), right (RCA), and left main trunk (LMT) of coronary artery were determined in 52 patients with coronary artery disease (CAD) using 64-slice multidetector computed tomography. Plasma levels of high-sensitivity CRP (hs-CRP) and matrix metalloproteinase (MMP)-9, as well as urinary 8-iso-prostaglandin F2α (PGF2α) were determined at the baseline. After the follow-up period, plaque progression in a specific vessel did not parallel that of other vessels, although changes in TDA-VWAs were weakly correlated with those of LMT-VWAs. Basal levels of hs-CRP, MMP-9, and PGF2α did not predict progression or regression of VWAs in any vessels. Multivariate analyses showed that LDL-cholesterol < 100 mg/dl and use of statin emerged as predictors of regressing VWAs in TDA (p < 0.05 and p < 0.05, respectively) and LMT (p < 0.05 and p = 0.13, respectively). Changes in soft plaques over 2 years paralleled those of VWAs in both coronary arteries. In conclusion, the progression or regression of atherosclerotic plaques is inhomogeneous among the vascular beds of patients with CAD.

The 5‐lipoxygenase inhibitor, zileuton, suppresses prostaglandin biosynthesis by inhibition of arachidonic acid release in macrophages

Zileuton is the only 5-lipoxygenase (5-LOX) inhibitor marketed as a treatment for asthma, and is often utilized as a selective tool to evaluate the role of 5-LOX and leukotrienes. The aim of this study was to investigate the effect of zileuton on prostaglandin (PG) production in vitro and in vivo. Peritoneal macrophages activated with lipopolysaccharide (LPS)/interferon γ (LPS/IFNγ), J774 macrophages and human whole blood stimulated with LPS were used as in vitro models and rat carrageenan-induced pleurisy as an in vivo model. Zileuton suppressed PG biosynthesis by interference with arachidonic acid (AA) release in macrophages. We found that zileuton significantly reduced PGE2 and 6-keto prostaglandin F1α (PGF1α) levels in activated mouse peritoneal macrophages and in J774 macrophages. This effect was not related to 5-LOX inhibition, because it was also observed in macrophages from 5-LOX knockout mice. Notably, zileuton inhibited PGE2 production in LPS-stimulated human whole blood and suppressed PGE2 and 6-keto PGF1α pleural levels in rat carrageenan-induced pleurisy. Interestingly, zileuton failed to inhibit the activity of microsomal PGE2 synthase1 and of cyclooxygenase (COX)-2 and did not affect COX-2 expression. However, zileuton significantly decreased AA release in macrophages accompanied by inhibition of phospholipase A2 translocation to cellular membranes. Zileuton inhibited PG production by interfering at the level of AA release. Its mechanism of action, as well as its use as a pharmacological tool, in experimental models of inflammation should be reassessed.

Urinary Prostaglandin E2 Was Increased in Patients With Suprapontine Brain Diseases, and Associated With Overactive Bladder Syndrome

To investigate the association between the urinary levels of prostaglandins (PGE(2) and PGF(2α)), nerve growth factor (NGF) and substance P, and overactive bladder (OAB) symptoms in patients with suprapontine brain diseases. The subjects were 114 patients in the chronic phase of a brain disease and 27 healthy controls with no brain disease or lower urinary tract symptoms (LUTS). The OAB symptoms were assessed with the OAB symptom score and the subjects were then classified into 5 groups: healthy control, patients without LUTS, increased bladder sensation (IBS), OAB dry, and OAB wet. Urinary mediator concentrations were measured using enzyme-linked immunosorbent assay and normalized to the urinary creatinine concentration, and then compared among the 5 groups. The urinary PGE(2) level was significantly higher in patients with brain diseases than in healthy controls, even in the patients without any OAB symptoms, and compared with patients without LUTS, a significant increase in the urinary PGE(2) was observed in patients with OAB dry or wet (P = .004 or .015, respectively). The PGF(2α) level showed a significant increase in OAB wet compared with patients without LUTS (P = .001). The urinary levels of NGF and substance P were not significantly associated with OAB as a result of this type of brain disease. The urinary PGE(2) level was putatively elevated in patients with suprapontine brain diseases and associated with the presence of OAB. The PGF(2α) level may also be associated with OAB.

Lipidomic profiling of endometrial fluid as a non-invasive diagnostic tool of human endometrial receptivity

OBJECTIVE: To investigate the lipid content in human endometrial fluid and the molecular mechanisms of endometrial prostaglandin (PG) production, in order to develop a non-invasive diagnostic tool of endometrial receptivity. DESIGN: Open blinded study on healthy female donors. MATERIALS AND METHODS: Endometrial fluid samples were collected from 39 fertile, regularly cycling volunteers aged 19-36 years with a normal BMI. Lipids content was identified by liquid chromatography combined with tandem mass-spectrometry. PG production was investigated using qPCR and immunohistochemistry in endometrial tissue. RESULTS: Lipids profile in endometrial fluid samples was analyzed in group I (days 0-8, n=8), group II (days 9-14, n=8), group III (days 15-18, n=8), group IV (days 19-23, n=8) and group V (days 24-30, n=7). Interestingly, during the clinical window of implantation (Group IV) PGE2 and PGF2α levels were significantly increased compared to all other groups. Analyses of endometrial epithelium at the mRNA and protein level point at mPGES1 and AKR1C3 as the enzymes responsible for the production of PGE2 and PGF2α, respectively, during the periimplantation period. We did not detect significant changes in the levels of CBR1 and AKR1C1, suggesting that production of PGE2 and PGF2α is mainly the result of PGH2 metabolism rather than an enzyme-driven switch between them.Tabled 1PGE2 and PGF2α concentration in human endometrial fluidPGE2 (moles/g ± SD)PGF2α (moles/g ± SD)Group I1.3E-09 ± 1.5E-092.9E-09 ± 2.9E-09Group II9.2E-11 ± 1.4E-101.1E-10 ± 1.4E-10Group III2.6E-09 ± 4.1E-094.5E-09 ± 5.4E-09Group IV∗U-Mann Whitney p<0.01 between group IV and all other groups.6.7E-09 ± 5.7E-092.4E-08 ± 1.9E-08Group V1.6E-09 ± 2.5E-093.5E-09 ± 4.1E-09∗ U-Mann Whitney p<0.01 between group IV and all other groups. Open table in a new tab CONCLUSION: PGE2 and PGF2α may represent novel predictors of human endometrial receptivity, thus opening the possibility for a non-invasive method to determine the clinical window of implantation.

Contribution of Vasoactive Eicosanoids and Nitric Oxide Production to the Effect of Selective Cyclooxygenase‐2 Inhibitor, NS‐398, on Endotoxin‐Induced Hypotension in Rats

Our previous studies with the use of non-selective cyclooxygenase (COX) inhibitor, indomethacin, demonstrated that prostanoids produced during endotoxaemia increase inducible nitric oxide synthase (iNOS) protein expression and nitric oxide synthesis, and decrease cyctochrome P450 (CYP) 4A1 protein expression and CYP 4A activity. The results suggest that dual inhibition of iNOS and COX by indomethacin restores blood pressure presumably due to increased production of 20-hydroxyeicosatetraenoic acid (20-HETE) derived from CYP 4A in endotoxaemic rats. The present study examined whether increased levels of vasoconstrictor eicosanoids, 20-HETE, prostaglandin F(2α) (PGF(2α) )and thromboxane A(2) (TxA(2) ), would contribute to the effect of selective COX-2 inhibition to prevent endotoxin (ET)-induced fall in blood pressure associated with an increase in the production of vasodilator prostanoids, prostaglandin I(2) (PGI(2) ) and prostaglandin E(2) (PGE(2) ) and nitric oxide synthesis. Mean arterial blood pressure fell by 31 mmHg and heart rate (HR) rose by 90 beats/min. in male Wistar rats treated with ET (10 mg/kg, i.p.). The fall in mean arterial pressure and increase in HR were associated with increased levels of 6-keto-prostaglandin F(1α) (6-keto-PGF(1α) ), PGE(2) , TxB(2) , and nitrite in the serum, kidney, heart, thoracic aorta and/or superior mesenteric artery. Systemic and renal 20-HETE and PGF(2α) levels were also decreased in endotoxaemic rats. These effects of ET were prevented by a selective COX-2 inhibitor, N-(2-cyclohexyloxy-4-nitrophenyl)methansulphonamide (10 mg/kg, i.p.), given 1 hr after injection of ET. These data suggest that an increase in 20-HETE and PGF(2α) levels associated with decreased production of PGI(2) , PGE(2) , and TxA(2) , and nitric oxide synthesis contributes to the effect of selective COX-2 inhibitor to prevent the hypotension during rat endotoxaemia.

Effects of regular black tea consumption on the antioxidant activity

Tea consumption is associated with the reduced risk of coronary heart disease.In order to evaluate the effects of black tea consumption on the antioxidant activity, we designed a randomized, controlled study that involves 5 servings (200 ml)/d of black tea for 6 weeks in 16 healthy female volunteers who do not normally consume tea in their life. Subjects were randomly divided into 2 groups (study and control). Plasma levels of total antioxidant activity (TOAC), malondialdehyde (MDA), oxidized LDL (ox‐LDL), 8‐isoprostane (8‐epi PGF2α), and some amino acids susceptible to oxidation, namely histidine, proline, lysine, threonine, leucine, isoleucine, tyrosine, phenylalanine, tryptophan, and valine were measured.TOAC significantly increased in the study group compared to the control group (1.81 ±0.1 vs 1.68 ±0.1). Plasma 8‐epi PGF2α level significantly decreased in the study group compared with the baseline (181.4 ±85.9 vs 164.0 ±94.1) however did not statistically changed between two groups. Although there was a positive trend in the results of oxidative biomarkers (MDA 1.46± 0.14 vs 1.42± 0.50, ox‐LDL 1928.9± 373.9 vs 1892.6± 284.6), we did not find significant difference between two groups. Amino acids susceptible to oxidation, except tryptophan, were significantly increased (p&lt; 0.05) in the study group.Daily 5 servings of black tea consumption significantly increased antioxidant activity.

The combined impact of plant-derived dietary ingredients and acute stress on the intestinal arachidonic acid cascade in Atlantic salmon (Salmo salar)

A study was conducted to assess the effect of substituting high levels of dietary fish oil (FO) and fishmeal (FM) for vegetable oil (VO) and plant protein (PP) on the intestinal arachidonic acid (AA) cascade in the carnivorous fish species Atlantic salmon. Four diets were fed to salmon over a period of 12 months, including a control FMFO diet, with varying replacements of plant-derived ingredients: 80 % PP and 35 % VO; 40 % PP and 70 % VO; 80 % PP and 70 %VO. Subsequently, fish were examined pre- (0 h) and post- (1 h) acute stress for blood parameters and intestinal bioactive lipidic mediators of inflammation (prostaglandins). Plasma cortisol responses were greatest in the FMFO group, while 80 % PP and 70 % VO fish exhibited increased plasma chloride concentrations. The n-3:n-6 PUFA ratio in intestinal glycerophospholipids from 70 % VO groups significantly decreased in both proximal and distal regions due to elevated levels of 18 : 2n-6 and the elongation/desaturation products 20 : 2n-6 and 20 : 3n-6. Increases in n-6 PUFA were not concomitant with increased AA, although the AA:EPA ratio did vary significantly. The 40 % PP and 70 % VO diet produced the highest intestinal AA:EPA ratio proximally, which coincided with a trend in elevated levels of PGF2alpha, PGE2 and 6-keto-PGF1alpha in response to stress. PGE2 predominated over PGF2alpha and 6-keto-PGF1alpha (stable metabolite of PGI2) with comparable concentrations in both intestinal regions. Cyclo-oxygenase-2 (COX-2) mRNA expression was an order of magnitude higher in distal intestine, compared with proximal, and was significantly up-regulated following stress. Furthermore, the 80 % PP and 70 % VO diet significantly amplified proximal COX-2 induction post-stress. Results demonstrate that high replacements with plant-derived dietary ingredients can enhance COX-2 induction and synthesis of pro-inflammatory eicosanoids in the intestine of salmon in response to acute physiological stress.

Effects of progesterone on motility and prostaglandin levels in the distal guinea pig colon

Progesterone (P4) inhibits the gastrointestinal muscle contraction by downregulating Galpha(q/11) proteins that mediate contraction, by upregulating Galpha(s) proteins that mediate relaxation, and by altering the pattern of cyclooxygenase (COX) enzymes and prostaglandins. We aimed to examine whether P4 treatment of guinea pigs in vivo affects basal colon motility [basal motility index (MI)] by altering the levels and actions of PGF(2alpha) and PGE(2). Guinea pigs were treated with intramuscular (IM) P4 for 4 days. The BASAL MI, the PGF(2alpha)-induced contraction, and PGE(2)-induced inhibition of contraction were examined in muscle strips and cells. The levels of PGF(2alpha) and PGE(2) were measured by radioimmunoassay. Treatment with P4 reduced the basal MI, the levels of PGF(2alpha), and PGF(2alpha)-induced contraction. P4 increased PGE(2) levels, and PGE(2) induced relaxation. Pretreatment with IM RU-486 (10 mg/kg per day), a P4 receptor antagonist, 1 h before P4 blocked the actions of P4. The PGF(2alpha) antagonist Al-1180 abolished basal MI and PGF(2alpha)-induced contraction. N-ethylmaleimide, which blocks unoccupied membrane receptors, blocked Ach and VIP actions but had no effect on PGF(2alpha) and PGE(2) effects. A COX-1 inhibitor decreased and a COX-2 inhibitor increased PGF(2alpha) levels; GTPgammaS increased and GDPbetaS decreased the levels of PGF(2alpha). Galpha(q/11) protein antibodies (Abs) reduced PGF(2alpha) levels, and Galpha(i3) Abs blocked its motor actions. Galphas Abs increased PGF(2alpha) but decreased PGE(2) levels. We concluded that P4 decreases basal MI by reducing PGF(2alpha) levels caused by downregulation of Galpha(q/11) and that PGF(2alpha)-induced contraction was blocked by downregulating Galpha(i3). P4 also decreased the basal MI by increasing PGE(2) levels, and PGE(2) induced relaxation by upregulating Galpha(s) proteins.

Moderate altitude but not additional endurance training increases markers of oxidative stress in exhaled breath condensate

Oxidative stress occurs at altitude, and physical exertion might enhance this stress. In the present study, we investigated the combined effects of exercise and moderate altitude on redox balance in ten endurance exercising biathletes, and five sedentary volunteers during a 6-week-stay at 2,800 m. As a marker for oxidative stress, hydrogen peroxide (H(2)O(2)) was analyzed by the biosensor measuring system Ecocheck, and 8-iso prostaglandin F2alpha (8-iso PGF2alpha) was determined by enzyme immunoassay in exhaled breath condensate (EBC). To determine the whole blood antioxidative capacity, we measured reduced glutathione (GSH) enzymatically using Ellman's reagent. Exercising athletes and sedentary volunteers showed increased levels of oxidative markers at moderate altitude, contrary to our expectations; there was no difference between both groups. Therefore, all subjects' data were pooled to examine the oxidative stress response exclusively due to altitude exposure. H(2)O(2) levels increased at altitude and remained elevated for 3 days after returning to sea level (p < or = 0.05). On the other hand, 8-iso PGF2alpha levels showed a tendency to increase at altitude, but declined immediately after returning to sea level (p < or = 0.001). Hypoxic exposure during the first day at altitude resulted in elevated GSH levels (p < or = 0.05), that decreased during prolonged sojourn at altitude (p < or = 0.001). In conclusion, a stay at moderate altitude for up to 6 weeks increases markers of oxidative stress in EBC independent of additional endurance training. Notably, this oxidative stress is still detectable 3 days upon return to sea level.

Ozone modulates IL-6 secretion in human airway epithelial and smooth muscle cells

Although ozone enhances leukocyte function and recruitment in airways, the direct effect of ozone in modulating structural cell-derived inflammatory mediators remains unknown. Using a coculture model comprised of differentiated human airway epithelial cells (NHBE) and smooth muscle cells (ASM), we postulate that ozone regulates IL-6 secretion in basal and cytokine-primed structural cells. Air-liquid interface (ALI) cultures of NHBE cells underwent differentiation as determined by mucin secretion, transepithelial electrical resistance (TEER), and ultrastructure parameters. Whereas TNF enhanced basal secretion of IL-6 (57 +/- 3%), ozone exposure at 0.6 ppm for 6 h augmented IL-6 levels in basal (41 +/- 3%) and TNF- (50 +/- 5%) primed cocultures compared with that derived from NHBE or ASM monolayers alone. Levels of PGE(2), 6-keto-PGF(1alpha), PGF(2alpha), and thromboxane B(2) (TxB(2)) levels in basal and TNF-primed cocultures revealed that ozone selectively enhanced PGE(2) production in TNF- (6 +/- 3-fold) primed cocultures, with little effect (P > 0.05) on diluent-treated cultures. In accordance with ozone-induced increases in PGE(2) levels, cyclooxygenase inhibition with indomethacin partially abolished IL-6 secretion. Surprisingly, indomethacin had little effect on constitutive secretion of IL-6 in cocultures, whereas indomethacin completely restored ozone-mediated TEER reduction in TNF-primed cocultures. Collectively, our data for the first time suggest a dual role of ozone in modulating IL-6 secretion and TEER outcomes in a PGE(2)-dependent (in presence of TNF stimulus) and -independent manner (in absence of cytokine stimulus).

257 DEVELOPMENT OF HEAT-STRESSED OVA MATURED IN THE PRESENCE OF A PROSTAGLANDIN F2ALPHA RECEPTOR ANTAGONIST

Studies in the literature have shown that cumulus–oocyte complexes produce PGF2α, that ova and cumulus cells have PGF2α receptors, and that PGF2α addition to maturing ova, above what would normally be produced, decreases blastocyst development. Because previous studies have shown elevated systemic and tissue levels of PGF2α as a consequence of heat stress, it was hypothesized that detrimental effects of exposing maturing ova to elevated temperatures may be mediated in part through heat-induced increases in PGF2α. To test this hypothesis, cumulus–oocyte complexes were matured at 38.5 or 41.0°C in the presence of a PGF2α receptor antagonist (AL-8810). Preattachment embryo development of AL-8810-treated ova was compared with development of ova matured in media with or without diluent (DMSO added at the same concentration as AL-8810; diluent and developmental controls, respectively), resulting in 6 total treatment combinations. Data were analyzed as a randomized block design (blocking on oocyte collection date) with fixed effects of maturation temperature, AL-8810, and the respective interaction included in the statistical model. In experimental replicates in which the effects of heat stress decreased blastocyst development greater than 10% (n = 14), a significant maturation temperature × AL-8810 interaction was noted when evaluating blastocyst development (P = 0.05). Specifically, when ova were heat stressed during the first 12 h of in vitro maturation, blastocyst development was reduced in developmental and diluent controls (26.2 v. 18.8 and 24.4 v. 19.9, respectively; SEM = 1.6). In contrast, when ova were matured under the same conditions but in the presence of a PGF2α receptor antagonist, the effects of heat stress to reduce blastocyst development after in vitro fertilization were no longer observed (22.5 v. 22.5; SEM = 1.6). When using abattoir-derived ovaries, it is not uncommon to collect, on occasion, ova that are developmentally challenged (i.e. blastocyst development is less than the 20 to 50% expected). In this experiment, this occurred on 5 occasions. Data from these experimental replicates were analyzed and reported separately because previous efforts had shown that the responsiveness of ova to changes in culture environment differs depending on the level of developmental competence. Relevant to this study, addition of AL-8810 to developmentally challenged ova matured under thermoneutral conditions increased cleavage (60.4 v. 55.4%, respectively; P = 0.06) and blastocyst development (17.7 v. 13.7%, respectively; P = 0.07). In summary, data illustrate that developmentally challenged ova, heat-stressed or otherwise, are susceptible to detrimental effects of PGF2α. The ability to increase blastocyst development approaching or exceeding the values expected for competent ova suggests the usefulness of a PGF2α receptor antagonist during in vitro maturation to improve the efficiency of in vitro production procedures.

An investigation into the role of prostaglandins in zebrafish oocyte maturation and ovulation

This study explored the potential for ovarian-derived prostaglandins (PGs) to be involved in the regulation of oocyte maturation and ovulation in zebrafish. It was demonstrated that cultured vitellogenic follicles have the capacity to produce prostaglandin E 2 (PGE 2) and PGF 2α in response to arachidonic acid (AA) in a concentration-dependent manner, and that AA stimulates the in vitro production of 17β-estradiol (E 2). The production of AA-stimulated PGF 2α was significantly reduced by treatment with the non-selective cyclooxygenase (COX) inhibitor, indomethacin (INDO). Treatment of full-grown follicles with AA did not induce oocyte maturation as assessed by germinal vesicle breakdown, but INDO significantly decreased the rate of spontaneous maturation. Using Real-Time PCR, it was shown that follicles of different developmental size classes (primary growth and pre-vitellogenic, early-vitellogenic, and mid- to full-grown vitellogenic) express enzymes that release (cytosolic phospholipase A 2 (cPLA 2); phospholipase Cγ1) or metabolize (COX-1, COX-2, and prostaglandin synthase-2) AA to PG metabolites. The expression of cPLA 2 was found to be significantly greater in full-grown follicles compared to follicles of the pre- and early-vitellogenic stages. In vivo studies demonstrated that breeding groups of zebrafish exposed to 100 μg/L INDO exhibited reduced spawning rates and clutch sizes compared with control and 1 μg/L INDO exposed fish. In other studies, it was shown that naturally spawning groups of females exhibit increased ovarian levels of PGF 2α, E 2, and 17α,20β-dihydroxy-4-pregnen-3-one (a maturation-inducing hormone in zebrafish) near the time of ovulation compared with non-breeding females. Collectively, these experiments indicate that the AA pathway in zebrafish ovaries is involved in the regulation of oocyte maturation and ovulation and a non-selective inhibitor of COX disrupts these processes.

High levels of urinary F2-isoprostanes predict cardiovascular mortality in postmenopausal women

F2-isoprostanes are prostaglandin-like compounds formed via arachidonic acid oxidation during oxidative stress. To study the relation between urinary concentrations of 8-iso-prostaglandin F2α (8-iso PGF2α) and mortality due to cardiovascular disease (CVD) in a nested case-cohort design. Follow-up duration of this prospective study among postmenopausal women was 18 years. Cases included 141 women who died of coronary heart disease and 109 women who died of stroke, whereas controls were a random cohort sample of 142 women. The concentration of 8-iso PGF2α was determined with liquid chromatography/tandem mass spectrometry in urine samples collected at baseline. Smokers had 34.8% higher urinary 8-iso PGF2α concentrations than nonsmokers (P < 0.001). High levels of urinary 8-iso PGF2α were associated with increased incidence of fatal CVD. Women who were in the highest quartile of urinary 8-iso PGF2α levels had, independently of age, an odds ratio of 1.8 (95% confidence interval, 1.1-3.1, P < 0.05) for CVD mortality. Further adjustment by systolic blood pressure, history of CVD, diabetes, smoking, and body mass index did not attenuate this association. Women with high levels of urinary 8-iso PGF2α had an 80% increased risk of dying of coronary heart disease or stroke, supporting involvement of oxidative stress in the pathophysiology of cardiovascular disease.

Two pathways for prostaglandin F2α synthesis by the primate periovulatory follicle

Prostaglandin E2 (PGE2) has been identified as a PG necessary for ovulation, but the ovulatory gonadotropin surge also increases PGF2 alpha levels in primate periovulatory follicles. To better understand the role of PGF2 alpha in ovulation, pathways utilized for PGF2 alpha synthesis by the primate follicle were examined. Monkeys were treated with gonadotropins to stimulate multiple follicular development; follicular aspirates and whole ovaries were removed before and at specific times after administration of an ovulatory dose of hCG to span the 40 h periovulatory interval. Human granulosa cells were also obtained (typically 34-36 h after hCG) from in vitro fertilization patients. PGF2 alpha can be synthesized from PGH2 via the aldo-keto reductase (AKR) 1C3. AKR1C3 mRNA and protein levels in monkey granulosa cells were low before hCG and peaked 24-36 h after hCG administration. Human granulosa cells converted PGD2 into 11 beta-PGF2 alpha, confirming that these cells possess AKR1C3 activity. PGF2 alpha can also be synthesized from PGE2 via the enzymes AKR1C1 and AKR1C2. Monkey granulosa cell levels of AKR1C1/AKR1C2 mRNA was low 0-12 h, peaked at 24 h, and returned to low levels by 36 h after hCG administration. Human granulosa cell conversion of [(3)H]PGE2 into [(3)H]PGF2 alpha was reduced by an AKR1C2-selective inhibitor, supporting the concept that granulosa cells preferentially express AKR1C2 over AKR1C1. In summary, the ovulatory gonadotropin surge increases granulosa cell expression of AKR1C1/AKR1C2 and AKR1C3. Both of these enzyme activities are present in periovulatory granulosa cells. These data support the concept that follicular PGF2 alpha can be synthesized via two pathways during the periovulatory interval.

Influence of Stress, Exertion, and Dietary Natural Source Vitamin E on Prostaglandin Synthesis, Hematology, and Tissue Fatty Acid Composition of Sunshine Bass

AbstractWe evaluated the effect of dietary natural source vitamin E (NSVE) on hematology and tissue composition of sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis) at rest and under the physical stress of exertion. Experimental diets were formulated to contain 1, 2, 5, or 30 times the dietary vitamin E requirement of sunshine bass as met by NSVE (22 mg NSVE/kg of feed, supplemental). After an 8‐week feeding trial, dietary treatment groups were subdivided for experimental exertion (forced swimming at 0.12 m/s): Control (no exercise), short‐term exertion (30 min), and long‐term exertion (180 min). Short‐term exertion induced the greatest plasma cortisol concentrations and depressed hematocrit. Dietary NSVE and exertion treatments were observed to affect eicosanoid synthesis via significant effects on cytosolic phospholipase (cPLA2) activity in adipose tissue but not white muscle or hepatic tissue. At rest, increasing NSVE was associated with increased adipose cPLA2 activity, suggesting elevated liberation of arachidonic acid (20:4[n‐6], where 20 is the number of carbon atoms, 4 is the number of double bonds, and 6 is the position of the first double bond from the methyl end) from this storage site; the ratio of 20:4(n‐6) to eicosapentaenoic acid (20:5[n‐3]) was accordingly reduced in adipose tissue. Resultant cardiac prostaglandin F2α (PGF2α) was also affected by dietary and exertion treatments; however, these results were not wholly congruent with alterations in cPLA2 activity. Levels of PGF2α decreased in association with the stress response but only among super‐requirement NSVE groups. Across all dietary treatments, exertion resulted in increased glucose liberation and minor reductions in hepatic glycogen stores. Exertion was not observed to affect tissue fatty acid composition, whereas increasing dietary NSVE was associated with minor changes in tissue composition. We conclude that dietary NSVE has some regulatory influence over eicosanoid synthesis but the mechanism is apparently not restricted to cPLA2‐mediated 20:4(n‐6) release. Moreover, NSVE may affect response to stressor exposure or exertion; however, further research is needed to fully elucidate the physiological consequences of super‐requirement NSVE supplementation.

Prostacyclin and Thromboxane Levels in Women with Severe Preeclampsia Undergoing Magnesium Sulfate Therapy During Antepartum and Postpartum Periods

Objective: To study effects of magnesium sulfate (MgSO4) on prostacyclin (PGI2) and thromboxane A2 (TXA2) levels in women with severe preeclampsia during antepartum and postpartum periods. Methods: Women with severe preeclampsia were randomized into two groups. Patients in Group A were continuously infused with MgSO4 for 24 hours postpartum. In Group B, MgSO4 administration was discontinued when urinary output was of ≥100 ml/hr for 2 consecutive hours. Patient demographic data were collected. Venous blood was drawn at time of MgSO4 administration and 24 hours after delivery. Plasma levels of 6-keto-PGF1α and TXB2, stable metabolites of PGI2 and TXA2, were measured by enzyme-linked immunosorbent assay (ELISA). Data are presented as mean ± SE, and analyzed by paired t-test. Results: A total of 50 patients were recruited, with 27 in Group A and 23 in Group B. There were no statistical differences for demographic data between the two groups with regards to maternal age; gestational age; systolic and diastolic blood pressures at admission, 12 hours postpartum, and 24 hours postpartum; and mode of delivery. Platelet counts were all within the normal range at the time of enrollment. MgSO4 was administered for an average of 10 hours postpartum in Group B. Maternal blood pressures returned to normal or close to normal levels in both groups at 24 hours postpartum. 6-keto PGF1α levels were significantly decreased 24 hours after delivery compared with the levels at enrollment in both groups, (Group A: 98 ± 13 vs. 180 ± 28 pg/mL; Group B: 142 + 17 vs. 194 ± 31 pg/mL, p < 0.05, respectively). However, there was no difference detected between the two groups. TXB2 levels were not different between group A and Group B at the time of enrollment, 38 ± 9 vs. 33 ± 8 pg/mL, and 24 hours postpartum, 26 ± 5 vs. 25 ± 3 pg/mL, respectively. Conclusions: Administration of MgSO4 does not affect prostacyclin and thromboxane levels in the maternal circulation in women with preeclampsia during antepartum and postpartum periods. We speculate that a higher level of prostacyclin before delivery may reflect compensatory effects of this vasodilator to offset increased maternal blood pressure during pregnancy.

Obese related effects of inflammatory markers and insulin resistance on increased carotid intima media thickness in pre-pubertal children

Obesity in children appears to be associated with increased risk of cardiovascular and metabolic diseases later in life. Early development of insulin resistance and impaired oxidant–antioxidant status may lead to endothelial dysfunction and increased carotid intima media thickness (IMT) even in childhood. The aim of this study was to measure IMT and the relationship between IMT, insulin resistance and oxidant status in obese pre-pubertal children. In 53 obese pre-pubertal children (27M/26F, mean age 8 ± 2 years), anthropometric measurements and inflammatory markers (hs-CRP and PGF-2α), were evaluated compared with 41 healthy pre-pubertal subjects (21M/20F, mean age 7 ± 2 years). OGTT was performed and insulin resistance (IR) indices (HOMA-IR, WBISI, G/I and QUICKI) were calculated in all patients. High-resolution ultrasound techniques were used to evaluate IMT. Obese children had higher levels of PGF-2α and hs-CRP compared to healthy subjects ( p = 0.001 and p = 0.005). Furthermore, fasting insulin levels and HOMA-IR were higher in obese children than in controls ( p = 0.001 and p = 0.001) while WBISI was significantly lower ( p = 0.002). In addition, obeses had an increased IMT ( p = 0.001). In obese children there was a significant correlation between IMT and indices of IR (HOMA-IR: β = −1.233, p = 0.002; WBISI: β = −0.921, p = 0.008; G/I: β = −0.811, p = 0.003) and between IMT and PGF-2α ( β = 0.505, p = 0.004). After categorizing subjects according to tertiles of body mass index (BMI) (≤21.42, 21.42–26.23 and ≥26.23 kg/m 2) and to waist circumference (WC) (≤68.28, 68.28–79.04 and ≥79.04 cm), no influence of BMI or WC on IMT were found in the three groups. In conclusion, early changes in glucose metabolism and an alteration of oxidant–antioxidant status may be present in obese pre-pubertal children; this could lead to increase IMT and early cardiovascular disease.