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Results 401 - 450 of 1138
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Kulkarni P S - - 1991
Arachidonic acid (AA) metabolism in the human and bovine retina was assessed. This study demonstrates that the human and bovine retina can synthesize prostaglandin (PG) E2, F2 alpha, I2, D2 and thromboxane A2 from 14C-AA. This tissue also synthesized leukotriene (LT) B4 and 12-hydroxyeicosatetraenoic acid (12-HETE). Although human and bovine ...
Conroy M C - - 1991
Meclofenamic acid is a nonsteroidal anti-inflammatory drug (NSAID) approved for use in arthritis (osteo and rheumatoid), analgesia (mild to moderate pain), dysmenorrhea, and heavy menstrual blood loss (menorrhagia). At least three different biochemical effects have been defined for meclofenamic acid. It is a potent inhibitor of the enzyme cyclooxygenase, thereby ...
King R G - - 1991
The human placenta contains both acetylcholine (ACh) and choline acetyltransferase, and in vitro bilaterally perfused placental lobules release ACh. The function of this placental cholinergic system has not yet been clearly defined, although changes occur in it during parturition and it may be linked to placental prostaglandin generation at this ...
Schewe C - - 1991
DL-omega-phenyl amino acid esters turned out to be inhibitors of the sheep vesicular gland prostaglandin H synthase in addition to their antiphlogistic action on the carrageenan-induced oedema of the rat paw and weak antihistaminic actions. The inhibition of the prostaglandin H synthase was dose-dependent, the inhibitory potencies were however much ...
Wilson D E - - 1991
Prostaglandins protect the gastroduodenal mucosa from damage caused by diverse noxious agents. This protection (cytoprotection) occurs under experimental conditions where intraluminal acid is required for maximal expression of damage (e.g., stress, aspirin, and bile acids), as well as where damage occurs irrespective of the presence of acid (e.g., 100% ethanol, ...
Taiwo Y O - - 1990
The nonsteroidal anti-inflammatory drugs are presumed to produce their analgesic effects by inhibiting the cyclooxygenase catalyzed metabolism of arachidonic acid to hyperalgesic prostanoids. This study examined the hyperalgesic effect of a range of prostaglandins. We found, employing the rat paw-withdrawal test, that while intradermal injection of the known hyperalgesic prostaglandins, ...
Herrmann F - - 1990
Peripheral blood-derived human polymorphonuclear leukocytes (PMNL) can be induced to synthesize prostaglandin E2 (PGE2) from endogenous and exogenous arachidonic acid (AA) when exposed to agents such as human recombinant (hr) granulocyte-macrophage (GM) colony-stimulating factor (CSF), hr tumor necrosis factor-alpha, hr granulocyte (G)-CSF, lipopolysaccharide and the chemoattractant N-formyl-methionyl-leucyl-phenylalanine. Treatment of PMNL ...
Hall E R - - 1990
A pan-specific monoclonal antibody that recognizes a variety of prostaglandin moieties and does not recognize arachidonic acid or the hydroxy-eicosatetraenoic acids was used to assess the general ability of a tissue to produce prostaglandins. Although this assay does not give a quantitative measure of PGH synthase activity, it does provide ...
Lippiello L - - 1990
Observations of impaired chondrocyte metabolism in essential fatty acid (EFA) deficiency as well as EFA protection against development of osteoarthrosis in inbred mice suggest the existence of a relationship between EFA, chondrocyte metabolism, and cartilage degeneration. To explore this relationship further, the fatty acid content of lipids in normal fetal ...
Short R M - - 1990
Eicosanoids are potent mediators of inflammation and are synthesized in increased quantity in active ulcerative colitis. To elucidate the role of prostaglandin E2, thromboxane A2, prostaglandin I2, and leukotriene B2 in acute chemical colitis induced by 4% acetic acid, we utilized an animal model which has a deficiency of arachidonic ...
Modéer T - - 1990
Bradykinin stimulated production of prostaglandin E2 (PGE2) and the release of 3H-arachidonic acid by gingival fibroblasts in a time- and dose-dependent manner. The effect on PGE2 biosynthesis was seen already after 15 seconds and was maximal after 5 minutes. Several structurally unrelated inhibitors of arachidonic acid metabolism via the cyclooxygenase ...
Erickson R A - - 1990
In a previous study we found that 16,16-dimethyl prostaglandin E2 protects the small intestine against chenodeoxycholic acid injury in the rat. One possible explanation for prostaglandin's protective action may be that prostaglandin-induced villus contraction accelerates mucosal restitution. This hypothesis was tested in rats by perfusing intestinal segments in vivo in ...
Hamilton S A - - 1990
Two experiments were conducted to determine if intrauterine infusion of nordihydroguaiaretic acid, a lipoxygenase pathway inhibitor, would delay luteolysis (Experiment 1) and inhibit oxytocin-induced release of prostaglandin F2 alpha (as measured by the stable prostaglandin F2 alpha metabolite, 15-keto-13,14-dihydroprostaglandin F2 alpha) in plasma on d 16 (d 0 = estrus) ...
Hsuanyu Y - - 1990
The reduction of prostaglandin H synthase compound II by ascorbic acid in the presence of diethyldithiocarbamate was studied in 0.1 M phosphate buffer (pH 8.0) at 4.0 +/- 0.5 degrees C, by rapid scan spectrometry and transient state kinetics. A saturation effect and nonzero intercept were observed in the plot ...
Mitchell E S - - 1990
Meclofenamic acid was used to inhibit prostaglandin synthesis in lambs challenged with Ostertagia circumcincta. It lowered the number of parasites which established in treated animals but not significantly. In treated animals plasma pepsinogen values were elevated at the time of parasite emergence but had dropped below the values achieved in ...
Aoyama T - - 1990
Cytochromes P450IVA1 and IVA3 display 72% amino acid sequence similarity and are expressed in livers of rats treated with the hypolipidemic drug clofibrate. The catalytic activities of IVA1 and IVA3 were examined by cDNA-directed expression using vaccinia virus. cDNA-expressed IVA1 and IVA3 had relative Mrs of 51,500 and 52,000, respectively, ...
Schlesinger R B - - 1990
Eicosanoids (arachidonic acid metabolites) are potent biological mediators. Modulation of their metabolism by air pollutants may be a possible factor in the pathogenesis of environmentally related lung disease. Sulfuric acid (H2SO4) aerosols are components of ambient air in many areas. Rabbits were exposed to H2SO4 (0.3 microns) at 250, 500, ...
Aungst B J - - 1990
The contributions of several proposed mechanisms by which fatty acids and amines might increase skin permeation rates were assessed. Permeation rates of model diffusants with diverse physicochemical properties (naloxone, testosterone, benzoic acid, indomethacin, fluorouracil, and methotrexate) through human skin were measured in vitro. The enhancers evaluated were capric acid, lauric ...
Ajayi F O - - 1990
Extracts and perfusate effluents of lungs of the rainbow lizard (Agama agama) were assayed for prostaglandin-like activity. Results of differential bioassay and thin-layer chromatography suggested that the prostanoid was predominantly PGE2-like. The mean PGE2-like content of 10 lizard lung extracts was 2.9 micrograms g-1 wet weight compared with 146 ng ...
White D M - - 1990
1. This study examined the effects of the 15-lipoxygenase product of arachidonic acid metabolism, (8R,15S)-dihydroxyicosa-(5E-9,11,13Z)tetraenoic acid (8R,15S-diHETE), on mechanical thresholds and thermal responses of saphenous nerve cutaneous C-fiber nociceptors that innervate the hairy skin of the rat hindpaw. Single C-fiber mechanoheat nociceptors (C-MH) that had von Frey hair (VFH) thresholds ...
Tanaka S - - 1990
The metabolism of arachidonic acid, lauric acid and prostaglandin A1 by rat hepatic microsomes and multiple forms of cytochrome P-450 purified from rat hepatic microsomes was studied. Arachidonic acid was hydroxylated by hepatic microsomes of male rats by omega- and (omega-1)-hydroxylation. Phenobarbital treatment of rats decreased the hydroxylation activity slightly, ...
Heim H K - - 1990
The purpose of this study is to evaluate the effects of different prostaglandin derivatives on protein and glycoprotein synthesis and secretion in isolated and enriched pig gastric mucous cells, as measured by the incorporation of [3H]L-leucine and N-acetyl-[14C]D-glucosamine respectively into acid insoluble macromolecules (AIM). PGE2 and 16,16-dimethyl-PGE2 enhanced the incorporation ...
Knapp H R - - 1990
Marine oils may offer cardiovascular benefits, but inhibition of prostaglandin E and prostaglandin F synthesis by fish oil has been found in animal studies, and such effects could alter physiological responses in man to a clinically significant degree. Since greater amounts of E and F-type prostaglandins are made in human ...
Offenbacher S - - 1990
Considerable evidence has demonstrated the importance of PGE2 synthesis in the pathogenesis of periodontal disease. Although various cyclooxygenase inhibitors have been known to block periodontal PGE2 synthesis and prevent disease progression in animal models, there are few reports comparing relative efficacies of various inhibitors of arachidonic acid (ARA) metabolism. We ...
Bennett P R - - 1990
Prostaglandin E2 production by amnion is thought to be an important event in the onset of human labor. It has been suggested that 5-hydroxyeicosatetraenoic acid, also produced in the amnion, may mediate prelabor contractions. For either of these compounds to play a paracrine role they need to cross the chorion, ...
Merkouris R W - - 1990
The influence of pregnancy on the circulating concentrations of atrial natriuretic factor, the 28 amino acid carboxy (C)-terminal end of the 126 amino acid atrial natriuretic factor prohormone, and the amino (N)-terminus of the prohormone was studied with three specific radioimmunoassays recognizing: (1) atrial natriuretic factor (i.e., amino acids 99 ...
Beck G - - 1990
Peptidoglycan (PG), an essential cell wall polymer of most bacteria, has been isolated from many species of spirochetes. Our interest in the host response to Borrelia burgdorferi led us to isolate and characterize its PG. Extracted cells were solubilized with warm 1% SDS followed by digestion with proteases. Amino acid ...
Itoh F - - 1990
Endothelial cells from human umbilical vein were incubated in vitro with thrombin in the absence or presence of unfractionated heparin (UFH), low molecular weight heparin (LMWH) or dermatan sulfate (DS) to clarify the effect of these glycosaminoglycans on thrombin-stimulated prostaglandin I2 (PGI2) production. Although DS did not affect the thrombin ...
England D W - - 1990
Using a specially designed incubation chamber, differential synthesis and the response to added arachidonic acid (25 mM) and L-alpha-phosphatidylcholine (LAP; 2 mM) was quantified in gallbladders from male and female dogs. Prostaglandin I2 (PGI2) was the predominant prostanoid synthesized, and tissues from females produced much more PGI2 under basal conditions ...
Vilaseca J - - 1990
Eicosanoids, as modulators of inflammation, may be involved in the pathogenesis of inflammatory bowel disease. We investigated their potential role in a rat model of chronic granulomatous colonic inflammation induced by trinitrobenzene sulphonic acid. Luminal eicosanoid release was quantified in vivo using a dialysis bag placed into the distal colon. ...
Kikuta Y - - 1990
Two forms of cytochrome P-450 (P-450), designated as P-450LPGA omega 1 and P-450LPGA omega 2, have been purified to specific contents of 17.9 and 11.1 nmol P-450/mg protein, respectively, from liver microsomes of rabbits treated with di(2-ethylhexyl)phthalate (DEHP), a peroxisomal proliferator. The purified P-450LPGA omega 1 and P-450LPGA omega 2 ...
Refoyo A - - 1990
Little is known about the distribution of prostaglandin E2 (PGE2) and prostacyclin (PGI2) production in the canine kidney. To determine the basal and stimulated profiles of PGE2 and PGI2 production along the corticomedullary axis of the dog kidney, a slice (0.5 mm thick, 10-50 mg) was obtained from six equally ...
Sumimoto H - - 1990
Leukotriene B4 (LTB4) omega-hydroxylase activity in human neutrophil microsomes was significantly inhibited by antisera against three rabbit omega-hydroxylase P-450s, lung prostaglandin omega-hydroxylase (P-450p-2), small intestine prostaglandin A omega-hydroxylase (P-450ia), and kidney fatty acid omega-hydroxylase (P-450kd). In contrast, the activity is not affected by antibodies raised against the phenobarbital-inducible forms of ...
Knowles S O - - 1990
1. The influence of nutrition and chronic lead (Pb) administration on the level of eicosanoids and their precursors was evaluated in serum and liver from chicks fed defined diets. 2. Dietary Pb consistently increased arachidonic acid, the arachidonate/linoleate ratio, and hepatic non-protein sulfhydryl concentration. 3. Hepatic microsomal fatty acid elongation ...
Krishna B R - - 1990
Indomethacin (1, 10 and 100 mumol L-1) was incrementally infused (8 min for each concentration) into the maternal and fetal circulations of dual-perfused human placental lobules, and measurements were made of materno-fetal amino acid transfer (using the non-metabolizable amino acid alpha-aminoisobutyric acid, or AIB) and fetal effluent perfusate prostaglandin (PG) ...
Ali M - - 1990
1. Homogenates of garlic (Allium sativum), onions (Allium cepa) and Allium porum were in vitro incubated with [14C]arachidonic acid. 2. Separation of labelled prostaglandins and thromboxanes were accomplished by thin-layer chromatography (TLC) and the Rf values were compared with those of authentic standards. 3. The prostaglandins identified were 6-keto-PGF1 alpha, ...
Siddiqui R A - - 1990
A proposed role for the hypothesized toxohormone/s (Vasopressin, Prostaglandin E2 and TNF-Cachectin) in the development and maintenance of cancer cachexia was investigated in rats bearing the Walker 256 carcinosarcoma. Elevated levels of arginine vasopressin and prostaglandin E2 in the plasma and urine were associated with reduced hepatic ketogenesis, fatty acid ...
Fedi P - - 1990
Pentagastrin-stimulated gastric luminal prostaglandin E2 (PGE2), 6-keto-PGF1 alpha, PGF2 alpha and thromboxane B2 (TxB2) were measured using a second antibody solid-phase enzyme immunoassay before, during and after cigarette smoking in healthy smokers. Smoking significantly increased PGF2 alpha and TxB2 concentration and output; in contrast no significant changes were found for ...
Adam O - - 1990
N-6 fatty acids comprise linoleic, dihomo-gamma-linolenic and arachidonic acid. Each of these polyunsaturated fatty acids display an individual pattern of cardiovascular effects. Moreover, the supplementation of the diet with one of these n-6 fatty acids results in a concomitant effect on the resorption, distribution and metabolism of the other n-6 ...
Miyazaki T - - 1990
In response to various stimuli, the pericardium produces prostaglandins that might play a role in neural regulation of cardiac electrophysiological properties by modulating epicardial nerve effects. We determined the effects of various epicardial superfusates on efferent cardiac responses, induced by bilateral efferent ansae subclaviae (SS) and cervical vagal (VS) stimulation, ...
Tanamoto K - - 1990
The ability of synthetic lipid A analogs to induce prostaglandin synthesis in macrophages was compared with that of native lipopolysaccharide. The synthetic preparations comprised monomeric or dimeric derivatives of D-glucosamine with different patterns of substitution by phosphate and tetradecanoic, (R)-3-hydroxytetradecanoic, and (R)-3-tetradecanoyloxytetradecanoic acid. All of these preparations are structurally distinct ...
Gimeno M A - - 1989
The uptake of arachidonic acid (AA) and of di-homo-gamma-linolenic acid (DGLA) and their incorporations into phospholipids (PLs) and into neutral lipids (NLs) of uteri isolated from spayed rats and the effect of inhibiting triglyceride (TG) metabolism with 4-pentenoic acid (4-PEA) on tissue TG levels and the output of prostaglandins (PGs), ...
Kohan D E - - 1989
Interleukin-1 (IL-1) has been demonstrated to cause a natriuresis and diuresis in experimental animals. This effect is associated with an increase in prostaglandin E2 (PGE2) excretion and is prevented by pretreatment with cyclooxygenase inhibitors. Micropuncture studies have shown IL-1 inhibition of sodium reabsorption by the rat papillary collecting duct (PCD), ...
Walsh S W - - 1989
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 ...
Rigas B - - 1989
Several products of arachidonic acid metabolism were assayed in whole saliva of patients with cystic fibrosis, a disease affecting primarily the exocrine glands. The levels of prostaglandins (PG) E2 and F2 alpha were elevated fourfold in patients with cystic fibrosis, compared with a control group (mean +/- SEM for PGE2 ...
Doyle M J - - 1989
Gastroprotection associated with the intragastric administration of prostaglandin (PG) precursor fatty acids such as linoleic (LA), gamma-linolenic (GLA), and arachidonic acid (AA) has been reported to be mediated via their conversion to PGs. This report examines the relationship between gastroprotection and the extent/rate of PG-release in rats intragastrically administered PG ...
Zakar T - - 1989
The purpose of this investigation was to study the mechanism of stimulation of PGE2 output from human amnion epithelial cells by the synthetic glucocorticoid dexamethasone. Cells incubated in serum-free pseudo-amniotic fluid produced very low levels of PGE2, even when arachidonic acid (1 microM) was present. Pretreatment of cells with dexamethasone ...
Oliw E H - - 1989
Microsomes of seminal vesicles of the cynomolgus monkey were incubated with [14C]5,8,11,14-eicosatetraenoic (arachidonic) acid and NADPH for 40 min at 37 degrees C and the products were characterized. Prostaglandins F2 alpha and E2 were the two main metabolites (approximately 52% of radioactivity), while 18(R)-hydroxy-cis-5,8,11,14-eicosatetraenoic acid (18(R)-HETE) was identified as the ...
Chandler D B - - 1989
Bleomycin is an anti-neoplastic compound which produces a time- and dose-dependent pulmonary fibrosis. The mechanisms which cause this fibrosis are not known. However, the ability of bleomycin to modulate prostaglandin synthesis, degradation and circulating levels appears to be central to the fibrosis. Previous studies, which have attempt to modulate bleomycin-induced ...
Ohuchi K - - 1989
Okadaic acid and dinophysistoxin-1 isolated from a black sponge, Halichondria okadai are non-12-O-tetrade-canoylphorbol 13-acetate (non-TPA)-type tumor promoters of mouse skin. Okadaic acid at concentrations of 10-100 ng/ml stimulated prostaglandin E2 production in rat peritoneal macrophages. Dinophysistoxin-1 (35-methylokadaic acid) stimulated prostaglandin E2 production as strong as okadaic acid, but okadaic acid ...
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