dinoprost and 5-hydroxy-6-8-11-14-eicosatetraenoic-acid

This study aimed to investigate the metabolite differences between patients with keratoconus and control subjects and identify potential serum biomarkers for keratoconus using a non-targeted metabolomics approach. Venous blood samples were obtained from patients with keratoconus (n = 20) as well as from age-, gender- and race-matched control subjects (n = 20). Metabolites extracted from serum were separated and analyzed by liquid chromatography/quadrupole time-of-flight mass spectrometer. Processing of raw data and analysis of the data files was performed using Agilent Mass Hunter Qualitative software. The identified metabolites were subjected to a principal component and hierarchical cluster analysis. Appropriate statistical tests were used to analyze the metabolomic profiling data. Together, the analysis revealed that the dehydroepiandrosterone sulfate from the steroidal hormone synthesis pathway was significantly upregulated in patients with keratoconus (p < 0.05). Also, a combination of eicosanoids from the arachidonic acid pathway, mainly prostaglandin F2α, prostaglandin A2, 16,16-dimethyl prostaglandin E2, and 5-hydroxyeicosatetraenoic acid were collectively up-regulated as a group in keratoconus patients (p < 0.05). On the other hand, glycerophospholipid PS(17:2(9Z,12Z)/20:4(5Z,8Z,11Z,14Z)) was found to be significantly upregulated in the metabolomics profiles of control subjects (p < 0.05). The differently regulated metabolites provide insights into the pathophysiology of keratoconus and could potentially be used as biomarkers for keratoconus to aid in screening for individuals at risk hence, enabling early diagnosis and timely monitoring of disease.

Topics: Adolescent; Adult; Biomarkers; Chromatography, High Pressure Liquid; Chromatography, Liquid; Dehydroepiandrosterone; Dinoprost; Dinoprostone; Female; Humans; Hydroxyeicosatetraenoic Acids; Keratoconus; Male; Metabolome; Metabolomics; Middle Aged; Prostaglandins A; Tandem Mass Spectrometry; Young Adult

To identify oxidative stress in peritoneum during laparoscopic and open surgery by measuring products of lipid peroxidation, and to determine whether surgical approach influences the type of oxidative metabolite synthesized.. Retrospective analysis (Canadian Task Force classification II-2).. University-affiliated hospital.. Twenty-eight consecutive women with uterine myomas or ovarian cysts.. Laparoscopic or open surgery (14 patients each).. We obtained 1 x 1-cm squares of peritoneum at the beginning and end of surgical procedures away from sites of surgery. 8-Isoprostaglandin F(2alpha), hydroxyeicosatetranoic acids (HETEs), and malondyaldehyde (MDA) were measured by enzyme-immunoassay, high-performance liquid chromatography, and thiobarbituric acid adduction method, respectively. Comparisons showed significant increases in 5-HETE and 8-prostane in the laparoscopy group, which were correlated with duration of pneumoperitoneum and volume of carbon dioxide (CO(2)) insufflated, respectively. In the laparotomy group only MDA rose significantly related to duration of surgery.. Lipid peroxidation was observed in peripheral peritoneum during laparoscopic surgery, mediated through noncyclooxygenase and lipoxygenase pathways, and appears to be due to effects of CO(2) pneumoperitoneum. Biochemical reactions were also observed in the laparotomy group, but are thought to be related to mechanisms other than lipid peroxidation.

Topics: Adult; Chromatography, High Pressure Liquid; Cohort Studies; Dinoprost; Enzyme-Linked Immunosorbent Assay; Female; Humans; Hydroxyeicosatetraenoic Acids; Laparoscopy; Laparotomy; Leiomyoma; Lipid Peroxidation; Malondialdehyde; Middle Aged; Ovarian Cysts; Oxidative Stress; Peritoneum; Pneumoperitoneum, Artificial; Probability; Retrospective Studies; Sensitivity and Specificity; Statistics, Nonparametric; Uterine Neoplasms

We investigated the effects of azelastine, an anti-allergic agent, on the release of arachidonic acid metabolites from cultured human umbilical vein endothelial cells (HUVEC). High performance liquid chromatography (HPLC) revealed that HUVEC treated with 10(-5) M azelastine released smaller amounts of arachidonic acid metabolites into the medium than control HUVEC. Azelastine significantly reduced the release of prostaglandin F2 alpha (PGF2 alpha), leukotriene B4 (LTB4) and 5-hydroxy-eicosatetraenoic acid (5-HETE) by HUVEC. These results suggest that azelastine may inhibit contraction of bronchial smooth muscle cells and reduce bronchial inflammation by suppressing the release of arachidonic acid metabolites from vascular endothelial cells.

Topics: Anti-Allergic Agents; Arachidonic Acid; Bronchoconstriction; Cells, Cultured; Chromatography, High Pressure Liquid; Dinoprost; Endothelium, Vascular; Humans; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Muscle Contraction; Phthalazines; Umbilical Veins

Renal glomerular injury frequently results in proliferation of a specialized supporting cell of the glomerular capillary known as the mesangial cell. In various forms of renal injury there is enhanced glomerular synthesis of specific eicosanoids of the arachidonic cyclooxygenase and lipoxygenase pathways including prostaglandin (PG) F2 alpha, thromboxane (Tx) A2, the hydroxyeicosatetraenoic acids 12-HETE and 5-HETE, and the leukotrienes LTB4 and LTD4 and attempts have been made to link these eicosanoids with injury-induced mesangial cell growth. In this study, the growth promoting effect of these eicosanoids on glomerular mesangial cells was correlated with activation of two growth regulatory enzymes: phospholipase C (PLC) and protein kinase C (PKC). PGF2 alpha, and TxA2 endoperoxide analog U-46619, and LTD4 significantly enhanced DNA synthesis [(as assessed by [3H]thymidine (TdR) incorporation)] in relatively quiescent (0.5% serum) mesangial cells, activated PLC [as assessed by increased 1,4,5-inositol tris-phosphate (IP3) generation and diacylglycerol (DAG) synthesis], and activated PKC (as assessed by translocation of the enzyme activity from the cytosol to the membrane). The effect of PGF2 alpha on IP3 generation was not blocked by the TxA2 receptor antagonist, SQ-29,548. PGF2 alpha was the most effective eicosanoid in inducing all three events, and concentrations that enhanced TdR incorporation (1 microM) also activated PLC and PKC. In contrast, concentrations of U-46619 and LTD4 which enhanced TdR incorporation (1 microM), also activated PLC, but were insufficient to also activate PKC. Our observations indicate that the growth-promoting effect of PGF2 alpha, U-46619, and LTD4 can best be correlated with PLC activation. In addition, PGF2 alpha does not mediate PLC activation through binding to the TxA2 receptor.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Animals; Cell Division; Diglycerides; Dinoprost; DNA; Eicosanoids; Enzyme Activation; Glomerular Mesangium; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Leukotriene D4; Prostaglandin Endoperoxides, Synthetic; Protein Kinase C; Rats; Rats, Sprague-Dawley; Receptors, Thromboxane; Signal Transduction; Thromboxane A2; Type C Phospholipases

Alveolar macrophages (AM) have been found to suffer significant functional deficits in response to nitrogen dioxide (NO2) exposure. The present investigation examined changes in the activation of AM arachidonate metabolism and superoxide production in response to an environmentally relevant level of NO2. Rats were exposed to 0.5 ppm NO2 for periods of 0.5-10 d and AM were obtained by bronchoalveolar lavage (BAL). NO2 exposure produced complex effects upon both unstimulated and stimulated AM arachidonate metabolism. Unstimulated AM synthesis of leukotriene B4 (LTB4) was depressed rapidly within 1 d of exposure, and depressed again at 5 d. Alveolar macrophage production of thromboxane B2 (TxB2), LTB4, and 5-hydroxyeicosatetraenoate (5-HETE) in response to stimulation with the calcium ionophore, A23187, were acutely depressed within 1 d of exposure; however, generation of these compounds recovered to air-control levels with longer exposure, while 5-HETE was increased at 10 d. In contrast, AM production of LTB4 in response to another stimulus, zymosan-activated rat serum (ZAS), was not depressed until following 5 d of exposure and remained slightly lower than air-control levels at 10 d. Levels of TxB2, LTB4, prostaglandin E2 (PGE2), and prostaglandin F2 alpha (PGF2 alpha) measured in BAL fluid (BALF) were found to be depressed within 4 h of exposure, suggesting an acute decrease in the in vivo pulmonary arachidonate metabolism; however, production of these compounds generally recovered to air-control levels with longer exposure. The AM superoxide production stimulated by phorbol myristate acetate (PMA) was decreased rapidly and continuously throughout the study. Thus, exposure to a low concentration of NO2 acutely depresses activation of AM arachidonate metabolism and superoxide production in response to external stimuli, and may impede defense against pulmonary infection.

Topics: Animals; Arachidonic Acids; Bronchoalveolar Lavage Fluid; Cell Count; Dinoprost; Dinoprostone; Glutathione; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Macrophages, Alveolar; Male; Nitrogen Dioxide; Oxidation-Reduction; Rats; Rats, Sprague-Dawley; Respiratory Burst; Specific Pathogen-Free Organisms; Superoxides; Thromboxane B2

We evaluated the effect of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 alpha (IL-1 alpha) on pig cardiopulmonary function by intravenously infusing each cytokine individually or in combination (0.5 microgram/kg from 0 to 0.5 h + 5 ng.kg-1 x min-1 from 0.5 to 6 h for each cytokine). The role of eicosanoids in mediating the TNF-alpha + IL-1 alpha-induced cardiopulmonary dysfunction was also investigated by pretreating cytokine-infused pigs with CGS 8515 (5-lipoxygenase inhibitor) or indomethacin (cyclooxygenase inhibitor). Coinfusion of TNF-alpha with IL-1 alpha caused additive increases (P < 0.05) in total peripheral resistance and plasma concentrations of 6-keto-prostaglandin F1 alpha (PGF1 alpha). The increases in mean pulmonary arterial pressure (Ppa), pulmonary vascular resistance (PVR), alveolar-arterial O2 gradient (AaDO2), alveolar dead space-to-tidal volume ratio (VD/VT), and plasma concentrations of thromboxane B2 were either additive or synergistic. CGS 8515 blocked the TNF-alpha + IL-1 alpha-induced increases (P < 0.05) in mean aortic pressure, total peripheral resistance (4-6 h), VD/VT (5-6 h), and, at 6 h, attenuated the increases in Ppa, PVR, and AaDO2. Indomethacin blocked or attenuated the cytokine-induced increases (P < 0.05) in Ppa, PVR, AaDO2, VD/VT, and plasma concentrations of thromboxane B2 and 6-keto-PGF1 alpha. The 1-to 2-h systemic hypotension, caused by TNF-alpha + IL-1 alpha, was not abrogated by either indomethacin or CGS 8515. The cytokines did not alter plasma concentrations of leukotriene B4 or 5-hydroxyeicosatetraenoic acid. We conclude that coinfusion of TNF-alpha with IL-1 alpha induces physiological responses that are additive or synergistic and that cyclooxygenase and 5-lipoxygenase products (other than leukotriene B4 and 5-hydroxyeicosatetraenoic acid) importantly mediate cardiopulmonary dysfunction in pigs infused with TNF-alpha + IL-1 alpha.

Topics: 6-Ketoprostaglandin F1 alpha; Albumins; Animals; Arachidonic Acids; Bronchoalveolar Lavage Fluid; Chromatography, High Pressure Liquid; Cyclooxygenase Inhibitors; Cytokines; Dinoprost; Drug Synergism; Eicosanoids; Heart; Heart Diseases; Hydroxyeicosatetraenoic Acids; Indomethacin; Injections, Intravenous; Interleukin-1; Leukotriene B4; Lipoxygenase Inhibitors; Lung; Lung Diseases; Naphthoquinones; ortho-Aminobenzoates; Swine; Thromboxane B2; Tumor Necrosis Factor-alpha; Vascular Resistance

The present study was undertaken to determine the ability of cultured luteal cells from human corpora lutea to secrete progesterone (P4) and prostaglandins (PGs), and to assess the effects of the products of the lipoxygenase pathway on luteal P4 production. Luteal cells responded to human chorionic gonadotropin (hCG) with a significant increase (2- to 7-fold) in P4 production. Arachidonic acid significantly stimulated PGE2 synthesis by luteal cells in a dose-dependent manner. Both basal PGE2 production and the responsiveness to arachidonic acid were maintained for 8 days. In contrast, both PGF2 alpha and 6-keto-PGF1 alpha production abruptly declined as the culture proceeded. However, the addition of hCG did not further stimulate the accumulation of the 3 PGs assayed. In the subsequent experiment, 5-hydroxyeicosatetraenoic acid (5-HETE) and the reaction products of soybean lipoxidase of arachidonic acid (AA-LIP) were utilized for evaluating the involvement of the lipoxygenase pathway in luteolysis. The addition of 5-HETE dose-dependently inhibited P4 production by the cultured luteal cells. Although treatment with either arachidonic acid or lipoxidase alone had no effect on P4 production, AA-LIP significantly reduced P4 production in the presence or absence of hCG. These results suggest that the products of the lipoxygenase as well as of the cyclo-oxygenase pathway may be important in regulating the life span and function of human corpora lutea.

Topics: Adult; Arachidonic Acid; Cell Division; Cells, Cultured; Chorionic Gonadotropin; Corpus Luteum; Dinoprost; Dinoprostone; Dose-Response Relationship, Drug; Female; Humans; Hydroxyeicosatetraenoic Acids; Lipoxygenase; Progesterone; Prostaglandins; Prostaglandins F

Arachidonic acid is metabolized by cyclooxygenase leading to prostaglandins (PG), and by lipoxygenases leading to hydroxyeicosatetraenoic acids (HETE) and leukotrienes (LT). PGs are potent uterine constrictors. 5-HETE and LTC4 also stimulate uterine contractions, but their role in labor is not known. To estimate the activities of these pathways before parturition and their relationship to uterine contractility, amniotic fluid (AF) concentrations of 5-HETE, LTC4 and PGF2 alpha were determined in 5 chronically catheterized rhesus monkeys. Uterine contractility was continually assessed by changes in AF pressure.. AF concentrations at the time of intrauterine surgery were 4.4 +/- 0.8 ng/ml for 5-HETE and 2.5 +/- 0.7 ng/ml for LTC4. PGF2 alpha levels were nondetectable. Indomethacin infusion into the mother, although effective in suppressing PGF2 alpha levels, did not prevent the onset of premature labor and vaginal delivery in 2 animals. PGF2 alpha did not increase in 1 monkey with term labor. Approximately 1 week before delivery, 5-HETE and LTC4 concentrations increased sharply in all animals in association with a nocturnal pattern of labor contractions. Peak AF concentrations during labor were 5-HETE: 40 +/- 8 ng/ml, LTC4: 20 +/- 4 ng/ml, and PGF2 alpha: 5.4 +/- 2.1 ng/ml.. LTC4 and 5-HETE stimulate uterine contractility in vitro, and probably act in concert with PGF and PGE to stimulate uterine contractions during parturition. HETEs may also act as a signal to recruit white blood cells to the uterus and to activate them, there to augment PG and LT production and act as a first line of defense against any infection that might enter the uterus from the vagina during or after delivery.. 1) 5-HETE and LTC4, but not PGF2 alpha, are associated with uterine contractility after preterm intrauterine surgery. Surprisingly, AF PGF2 alpha levels were nondetectable for 1 to 2 weeks after surgery. 2) 5-HETE and LTC4 are present in higher concentrations than PGF2 alpha in AF. 3) 5-HETE, LTC4 and PGF2 alpha all increase with the onset of labor. AF concentrations of 5-HETE and LTC4 are significantly higher than PGF2 alpha before and during term and preterm labor. 4) Labor can occur with suppressed PGF2 alpha levels, but with increasing 5-HETE and LTC4 levels. 5) These data suggest that 5-HETE and LTC4 are important components of the parturitional process, and they challenge the dogma that PGs are the universal mediators of labor.

Topics: Amniotic Fluid; Animals; Dinoprost; Female; Hydroxyeicosatetraenoic Acids; Labor, Obstetric; Macaca mulatta; Pregnancy; SRS-A

The present study was undertaken to assess the effects of the products of the lipoxygenase pathway on steroidogenesis and the production of prostaglandins (PGs) by human corpora lutea in the midluteal phase. In the first experiment luteal cells were cultured with 5-hydroxyeicosatetraenoic acid (5-HETE) at 10, 100, 500, or 1000 ng/mL in the presence or absence of hCG at 100 ng/mL for 10 days. The addition of 5-HETE dose-dependently inhibited progesterone (P) production by the cultural luteal cells. P production stimulated by exposure to hCG was also reduced significantly in response to 5-HETE. However, 5-HETE had no effect on the production of 6-keto-PGF1 alpha, PGF2 alpha, or PGE2 by cultured luteal cells at any point during the culture period. In the second experiment the reaction products of soybean lipoxidase of arachidonic acid (AA-LIP) were added to cultured luteal cells. Treatment with either AA or LIP alone had no effect on basal P production. The addition of AA-LIP at all concentrations tested reduced P production by cultured luteal cells in the presence or absence of hCG. AA-LIP significantly reduced basal 6-keto-PGF1 alpha secretion in cultured luteal cells on day 2. Although the stimulatory effect of AA on luteal PGE2 production was maintained throughout the entire culture period, the lipoxygenase products of AA did not affect AA-stimulated PGE2 production by cultured luteal cell. These results suggest that the products of the lipoxygenase pathway may be important in the involution of human corpora lutea.

Topics: Adult; Arachidonic Acid; Arachidonic Acids; Cells, Cultured; Chorionic Gonadotropin; Corpus Luteum; Dinoprost; Dinoprostone; Dose-Response Relationship, Drug; Female; Humans; Hydroxyeicosatetraenoic Acids; Lipoxygenase; Luteal Cells; Progesterone; Prostaglandins; Prostaglandins F

We attempted to explore possible mechanism(s) subserving the influence of oxytocin on uterine motility by studying the action of the hormone on: 1) the contractile activity of isolated rat uteri in the presence or absence of indomethacin; 2) the synthesis and release of prostaglandins (PGs) into the solution incubating the uterine tissue as well as the metabolism of labelled arachidonic acid; 3) the uptake of 45Ca2+ by uterine strips. The experiments were bone with uterine preparations isolated from spayed rats treated or not with 17-beta-estradiol. The values of isometric developed tension (IDT) and of frequency of contractions (FC) induced by oxytocin in uterine strips isolated from spayed and spayed-estrogenized rats, were not modified by indomethacin at 10(-6) M. On the other hand, uterine strips from untreated spayed rats, release into the incubating medium approximately equal amounts of PGE1, PGE2 and PGF2 alpha. The in vitro presence of oxytocin (50 mU/ml) increased significantly (p 0.05) the output of PGF 2 alpha without changing the release of PGE1 or PGE2. Uteri from spayed rats injected prior to sacrifice with 17-beta-estradiol released significantly less PGE1 and PGE2 (p less than 0.005) than preparations from non-injected animals, whereas the output of PGF2 alpha in the suspending solution remained unchanged. Following estrogenization the addition of oxytocin to preparations obtained from spayed-estrogenized rats also increased the output of uterine PGF2 alpha (p less than 0.001) without changing that of PGs E1 or E2.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Alprostadil; Animals; Arachidonic Acids; Calcium; Dinoprost; Dinoprostone; Estradiol; Female; Hydroxyeicosatetraenoic Acids; Indomethacin; Muscle Contraction; Oxytocin; Rats; Rats, Inbred Strains; Uterus

Recently identified Ascaris suum sensitive cynomolgus monkeys were further characterized to determine if a chronologic relationship existed between mediator release and onset of bronchoconstriction. In these anesthetized Ascaris-sensitive monkeys, aerosol antigen challenge of each animal produced rapid and severe bronchoconstriction, as determined by decreases in dynamic lung compliance (-80.2 +/- 4.1%) and airway conductance (-64.5 +/- 13.8%). Maximum changes were achieved within 5 min following exposure and remained substantially altered throughout the 30 min observation period. However, changes in pulmonary function related to duration of onset and maximum change seemed to have some correlation with each animals' sensitivity to the antigen. Comparison of pre- and post-challenge blood gas profiles, showed a progressive formation of respiratory acidosis through decreases in arterial blood pH, partial pressure of O2 (pO2), O2 saturation (sO2) and an increase in partial pressure of CO2 (pCO2). When arterial blood plasma was assayed by RIA for mediators of anaphylaxis, large increases in 5-hydroxyeicostetraenoi acid (5-HETE), leukotriene B4 (LTB4) and histamine were observed. No amount of prostaglandin F2-alpha (PGF2 alpha) or thromboxane A2 were detected. Two of the three monkeys also produced detectable amounts of leukotriene C4 (LTC4). Therefore, in Ascaris-sensitive monkeys, histamine is the predominate mediator released and is probably responsible for at least the early part (5-10 min) of the observed bronchoconstriction. However, mediators from the lipoxygenase pathway may also be playing a role in the antigen-induced bronchoconstriction, especially beyond the 10 min period following anaphylaxis.

Topics: Animals; Antigens, Helminth; Ascaris; Asthma; Dinoprost; Histamine; Histamine Release; Hydroxyeicosatetraenoic Acids; Leukotrienes; Macaca fascicularis; Male; Radioimmunoassay; Respiratory Function Tests; Thromboxane B2; Time Factors

Arachidonic acid is metabolized by cyclooxygenase leading to prostaglandins and by lipoxygenases leading to hydroxyeicosatetraenoic acids (HETE) and leukotrienes (LT). Prostaglandins are potent uterine constrictors. 5-HETE and LTC4 also stimulate uterine contractions but their role in labor is not known. To estimate the activities of these pathways before parturition and their relationship to uterine contractility, amniotic fluid concentrations of 5-HETE, LTC4, and prostaglandin F2 alpha (PGF2 alpha) were determined in five chronically catheterized rhesus monkeys. Uterine contractility was continually assessed by recording changes in amniotic fluid pressure. The results obtained indicate the following conclusions: (1) 5-HETE and LTC4, but not PGF2 alpha, are associated with uterine contractility after preterm intrauterine surgery. Surprisingly, amniotic fluid PGF2 alpha, levels were nondetectable for 1 to 2 weeks after surgery. (2) 5-HETE and LTC4 are present in higher concentrations than PGF2 alpha in amniotic fluid. (3) 5-HETE, LTC4, and PGF2 alpha all increase with the onset of labor. Amniotic fluid concentrations of 5-HETE and LTC4 are significantly higher than those of PGF2 alpha before and during term and preterm labor. (4) Labor can occur with suppressed PGF2 alpha levels but with increasing 5-HETE and LTC4 levels. (5) These data suggest that 5-HETE and LTC4 are important components of the parturitional process.

Topics: Amniotic Fluid; Animals; Dinoprost; Female; Hydroxyeicosatetraenoic Acids; Labor, Obstetric; Macaca mulatta; Obstetric Labor, Premature; Osmolar Concentration; Pregnancy; SRS-A

The profile of cyclooxygenase and lipoxygenase products in normal rat colonic epithelium and subepithelium was examined. Colons were thoroughly perfused to eliminate contamination with blood. Two preparations of colonic epithelium were employed. The first consisted of intact colonic crypts and epithelial sheets. The second yielded single cell suspensions of superficial versus proliferative epithelial cells. Lipoxygenase product formation by colonic epithelium as measured by hydroxyeicosatetraenoic acid (HETE) and leukotriene B4 (LTB4) production (5-HETE greater than 12-HETE greater than 15-HETE greater than LTB4) accounted for 58% of the total colonic production of these moieties, whereas epithelium accounted for only 20% of total colonic protein. By contrast, prostaglandin (PG) E2 and PGF2 alpha production occurred predominantly (greater than 97%) in the subepithelial layers. The present studies also demonstrate markedly higher levels of accumulation of lipoxygenase products in proliferative versus superficial epithelial cells, whereas prostaglandin accumulation was greater in superficial cells. Previous studies have supported a role for lipoxygenase and cyclooxygenase products in the control of colonic secretion, inflammatory cell infiltration and proliferative activity. The present results raise the possibility that the striking differences in the sites of production of these products within the colon has functional implications.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Colon; Dinoprost; Dinoprostone; Eicosanoic Acids; Epithelium; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Lipoxygenase; Prostaglandin-Endoperoxide Synthases; Prostaglandins E; Prostaglandins F; Radioimmunoassay; Rats

To determine whether chronic glucocorticoid excess influences the metabolism of arachidonic acid to prostaglandins (PGs) in the renal cortex, the authors investigated the effects of dexamethasone treatment (2.5 mg/kg/week) on the metabolism of arachidonic acid by renal cortex homogenates and microsomes and by isolated glomeruli, and on the release of immunoreactive prostanoids from isolated glomeruli incubated for 30 min in buffered salt solution at 37 degrees C. Glomeruli from dexamethasone-treated rats released, during basal incubation conditions, about twice (P less than .01) as much PGE2 and PGF2 alpha as did glomeruli from vehicle-treated rats. During incubation with arachidonic acid (33 microM) or calcium ionophore, A23187 (2.0 micrograms/ml), the release of PGE2 and PGF2 alpha from glomeruli of rats receiving dexamethasone also exceeded (P less than .01) the release from glomeruli of control rats. The rate of conversion of [1-14C]arachidonic acid to PGE2 and PGF2 alpha and to less polar metabolites having the chromatographic mobility of 5-hydroxyeicosatetraenoic acid and 12-hydroxyeicosatetraenoic acid, by isolated glomeruli and by renal cortex homogenates and microsomes from dexamethasone-treated rats, was higher (P less than .01) than the conversion by glomeruli and renal cortex homogenates and microsomes from control rats. The metabolism of arachidonic acid to the nonpolar metabolite(s) was not inhibited by indomethacin (10 microM), suggesting that it is not catalyzed by cyclooxygenase. The authors conclude that chronic dexamethasone treatment increases the release of glomerular PGE2 and PGF2 alpha and the metabolic transformation of arachidonic acid by glomeruli and by renal cortex homogenates and microsomes via both cyclooxygenase and noncyclooxygenase pathways.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Arachidonic Acid; Arachidonic Acids; Calcimycin; Dexamethasone; Dinoprost; Dinoprostone; Hydroxyeicosatetraenoic Acids; Indomethacin; Kidney Cortex; Kidney Glomerulus; Male; Microsomes; Prostaglandins; Prostaglandins E; Prostaglandins F; Rats; Rats, Inbred Strains

It has been demonstrated that the level of prostaglandin F2 alpha and 5-hydroxyeicosatetraenoic acid (5-HETE) in the serum of alloxan-diabetic rats is reduced by 85% and 25%, respectively, whereas that of prostaglandin E2 is increased by 34%. The administration of trihydroxyoctadecadienoic acids, that have a hypoglycemic effect, to diabetic animals brings about a rise in the level of prostaglandins F2 alpha, E2 and 5-HETE by 33%, 64% and 279%, respectively, as compared to the control.

Topics: Animals; Diabetes Mellitus, Experimental; Dinoprost; Dinoprostone; Drug Evaluation, Preclinical; Fatty Acids, Unsaturated; Hydroxy Acids; Hydroxyeicosatetraenoic Acids; Hypoglycemic Agents; Male; Prostaglandins E; Prostaglandins F; Rats

Within 5 min, resting macrophages metabolize microM quantities of exogenous arachidonic acid (20:4) to cyclooxygenase and lipoxygenase products. Mono-HETEs represent a major class of metabolites recovered from the medium. However, the quantity of mono-Hetes progressively decreases over a 60-min incubation period, with a concomitant increase in more polar lipoxygenase products, suggesting additional metabolic fates for these hydroxy acids. This was directly confirmed by exposing resident macrophage cultures to radiolabeled 15-, 12-, and 5-HETEs (1 microM). 12-30% of the recovered HETEs were cell-associated and predominantly esterified into phospholipid. High pressure liquid chromatography analyses of medium extracts indicated that 50% of each HETE was also converted to 10 or more metabolites over a 60-min time-course, a rate slower than for 20:4. The major metabolite generated from each mono-HETE had the elution characteristics of a di-HETE. The 5-HETE product has a triene spectrum similar to that of 5(S), 12(S)-di-HETE, whereas the 15- and 12-HETE products exhibited single ultraviolet absorption maxima, indicating a metabolic pathway for 5-HETE distinct from the other mono-HETEs. None of the stable cyclooxygenase products of 20:4 (6-keto PGF1 alpha, PGF2 alpha, PGE2, TXB2) nor polar metabolites of mono-HETEs are either incorporated or metabolized. The results indicate that macrophages have the capacity to specifically metabolize 20:4 and mono-HETEs to polar oxygenated products in the absence of a discernible trigger.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Arachidonic Acids; Dinoprost; Dinoprostone; Female; Humans; Hydroxyeicosatetraenoic Acids; Macrophage Activation; Macrophages; Male; Mice; Mice, Inbred ICR; Phosphatidylcholines; Phospholipids; Prostaglandins E; Prostaglandins F; Thromboxane B2; Time Factors

The capacity of chicken aorta to produce prostaglandins both from exogenous and endogenous arachidonic acid has been evaluated. The metabolism of arachidonic acid in this tissue is mainly directed to PGE2 and, in contrast to mammalian species, virtually no prostacyclin synthetase is present. However, the capacity of chicken thrombocytes to generate thromboxane A2 and 12-L-hydroxy-5, 8, 10, 14-eicosatetraenoic acid is similar to that observed for the mammalian blood platelets.

Topics: Animals; Aorta; Arachidonic Acid; Arachidonic Acids; Blood Platelets; Chickens; Dinoprost; Dinoprostone; Epoprostenol; Hydroxyeicosatetraenoic Acids; Male; Muscle, Smooth, Vascular; Prostaglandin D2; Prostaglandins; Prostaglandins D; Prostaglandins E; Prostaglandins F; Thromboxane A2; Turkeys