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1.
A rapid and convenient method is described for methylating prostanoids and other arachidonic acid metabolites. With 3H-methyl iodide of high specific activity, tracers for radioimmunoassay can be produced at a cost which is only a fraction of that of labeled compounds currently available. In radioimmunoassays for PGE2, TXB2 and 6-keto -PGF1α, labeled methyl esters gave results which were comparable to those obtained with the use of tritiated free acids as radioligands. 相似文献
2.
《Biochemical and biophysical research communications》1986,138(1):496-501
We have tested the direct regulatory effect of synthetic Atrial Natriuretic Peptide (ANP, 8-33aa) on prostaglandins and renin release by isolated rat glomeruli. Variable incubation times and doses of ANP did not modify the rate of PGE2, PGF2a and TXB2 production. Similar results were obtained for renin release. These data do not support a role for ANP in the regulation of prostaglandins and renin release by rat glomeruli. 相似文献
3.
The conversion of arachidonic acid to prostaglandins (PG's) and thromboxane B2 (TXB2) was investigated in homogenates from fetal and adult bovine and rabbit lungs. Adult bovine lungs were very active in converting arachidonic acid (100 μg/g tissue) to both PGE2 (10.7 μg/g tissue) and TXB2 (6.2 μ/g tissue). Smaller amounts of PGF2α (0.9 μ/g) and 6-oxoPGF1α were formed. Homogenates from fetal calf lungs during the third trimester of pregnancy were quite active in converting arachidonic acid to PGE2, but formed very little TXB2, PGF2α or 6-oxoPGF1α. Homogenates from rabbit lungs converted arachidonic acid (100 μg/g) mainly to PGE2, both before and after birth. The amount of PGE2 formed increased during gestation to a maximum of about 6 μg/g tissue at 28 days of gestation. It then decreased to a minimum (1.5 μg/g) which was observed 8 days after birth, followed by an increase to about 4 μg/g in older rabbits. 相似文献
4.
Bovine gastric mucosal and muscle microsomes synthesize prostaglandins and thromboxane B2 (TXB2) from arachidonic acid (AA). TXB2 and 6-keto-prostaglandin F1α (6-keto-PGF1α) were the major products synthesized by pylorus, body, and cardiac region of the gastric mucosa. Gastric muscle mainly synthesized 6-keto-PGF1α. TXB2 and 6-keto-PGF1α synthesis occurs at an appreciable rate from endogenous precursors but more rapidly with added arachidonate. Prostaglandins E2, F2α and D2 were synthesized in smaller amounts under the conditions studied. 相似文献
5.
《Prostaglandins, Leukotrienes and Medicine》1983,10(3):309-317
6 patients with end-stage renal disease underwent hemoperfusion with charcoal colums, for 60 min. Blood samples anticoagulated with 2% EDTA/aspirin solution were obtained from arteriovenous fistulas in the basal condition, 5 min after a bolus injection of heparin (7,500 U), at the end of hemoperfusion, and 30 min after. The study was repeated few days later, in the same patients, two hours after 100 mg aspirin by mouth. TXB2 and 6-keto-PGF1α were assayed with RIA in unextracted (U) and extracted (E) and chromatographed platelet poor plasma (PPP). Platelet counts before and after hemoperfusion were also performed. Low levels of the two prostaglandins were found in plasma; this could be related to the procedures for collection and processing of plasma samples; no significant differences were observed between extracted and unextracted samples: there were slightly higher levels of 6-keto-PGF1α in unextracted samples. After charcoal hemoperfusion there was only a slight and not significant increase of TXB2 and 6-keto-PGF1α; low dose aspirin did not modify significantly plasma levels of the two prostaglandins before hemoperfusion but it reduced TXB2 and 6-keto-PGF1α levels after charcoal hemoperfusion. The platelet count fell (−22%) after charcoal hemoperfusion with heparin alone and in a similar manner after lowdose aspirin pretreatment (−24,7%). 相似文献
6.
C.W. Bales M.C. Wang J.H. Freeland-Graves R.S. Pobocik 《Prostaglandins & other lipid mediators》1986,31(5)
Zinc has been implicated in the regulation of prostaglandins and other arachidonic acid derivatives. Studies of zinc-deficient animals, however, are compromised by concomitant reduction in food intake that may also alter eicosanoid levels in body tissues and fluids. In this study, three groups of rats, designated as zinc-deficient, pair-fed and control, were fed diets containing 1 ppm, 15 ppm (in amounts paired to deficient rats) and 15 ppm Zn adlibitum, respectively, for 6 weeks. Saliva and blood were analyzed for PGE2 adn TXB2 by radioimmunoassay. Saliva concentrations of both eicosanoids were lower (p<0.05) in the pair-fed animals, but not significantly altered by zinc deficiency. Plasma levels of PGE2 and TXB2 were unchanged by either zinc deficiency or food restriction. The results of this study support the contention that the effect of zinc on these prostaglandins is not mediated by altered rates of synthesis or degradation but rather by effects on eicosanoid function. 相似文献
7.
Nine underivatized prostaglandins were examined using direct exposure, ammonia, chemical-ionization, pulsed positive-negative ion mass spectrometry. The positive ion spectra were characterized by (M+18)+ ion adducts. The negative ion spectra were characterized by ions which dependence upon the functionality present in the cyclopentane ring system (acetal for TXB2). The E and D series prostaglandins gave (M-18)− as the major negative ion, while the F series and TXB2 were characterized by negative ions corresponding to (M-1)−, and PGA2 by the parent (M)− ion. Prostaglandin 6-keto-PGF1α was anomalous in this respect showing apparent dehydration, interpreted as an overall (M-18+1)+ and (M-18-1)− in the positive and negative ion spectra, respectively. All major ion types were shown to give essentially a linear response with respect to concentration in the 10–1000 ng range. Although these initial studies were conducted under ideal conditions, it would appear that direct chemical ionization techniques show promise for providing direct structural information on prostaglandins without the need for prior chemical derivation. 相似文献
8.
Kennedy Michael S. John D. Stobo Marc E. Goldyne 《Prostaglandins & other lipid mediators》1980,20(1):135-145
This report focuses on the identification of the human peripheral blood mononuclear cells that do or do not produce prostaglandins (PGs) and related arachidonic acid metabolites. Our results, using two different assay systems, indicate that the monocyte/macrophage (MØ) is the major and possibly sole source of thromboxane (TXB2) and prostaglandin E2 (PGE2) among peripheral blood mononuclear cells. Adherent peripheral blood monocytes (> 95% esterase positive) produced substantial amounts of these compounds. Quantitation of products which had incorporated exogenous 14C-arachidonic acid and radioimmunoassay of adherent cell culture fluids demonstrated that the amount of TXB2 produced by these cells was appreciably greater than the amount of PGE2 produced. Additional confirmation of TXB2 synthesis was shown by abolishing the TXB2 peak on TLC and TXB2 activity detected by RIA by treating cells with a specific inhibitor of thromboxane synthetase. In contrast, non-adherent T cells failed to synthesize either PGE2 or TXB2. Non-adherent B cells (95% Ig positive) incubated with 14C-arachidonic acid produced a small peak of radioactivity co-chromatographing with TXB2, and no PGE2. All three cell populations incorporated similar amounts of 14C-arachidonic acid into hydroxy-fatty acids. We were unable to detect 6-keto-F1α, the hydrolysis product of prostacyclin (PGI2) in any of the cell types tested. The absence of PG synthesis among normal peripheral blood T and B cells was also noted among established human lymphoid cell lines. Neither a human T (CCRF), nor a human B-cell line (GM-130), produced PGE2 or TXB2. Three murine macrophage cell lines, P388D1, J774.2, and WHI-3 produced PGE2 and the latter TXB2 as well. 相似文献
9.
Jose Sraer Nicole Ardaillou Jean-Daniel Sraer Raymond Ardaillou 《Prostaglandins & other lipid mediators》1982,23(6):855-864
We have investigated in vitro prostaglandin synthesis by human isolated glomeruli and papillary homogenates and compared the results with those obtained in parallel studies using rat material. Prostaglandins were measured by two methods, namely radiometric high performance liquid chromatography after incubation with 14C arachidonic acid and radioimmunoassay. The relative abundance of various prostaglandins synthesized by glomeruli was different in man (6 keto PGF1α > TXB2 > PGF2α > PGE2) and in the rat (PGE2 TXB2 > 6 keto PGF1α). Unidentified peaks eluting between 6 keto PGF1α and TXB2 were observed only in rat glomeruli. These peaks were suppressed by indomethacin. Direct radioimmunoassay of prostaglandins in the incubation medium of human glomeruli confirmed the predominance of 6 keto PGF1α synthesis and showed its stimulation by arachidonic acid, its progressive decrease with time and its linear relationship with glomerular protein at low concentrations. On the contrary, the profile of prostaglandin synthesis by the papilla was similar in man and in the rat, PGE2 and PGF2α being the major products in both species. However, related to one mg of protein, papillary synthesis of these two prostaglandins was greater in the rat. These results show that PGI2 is the major prostaglandin synthesized in human glomeruli and suggest a role for this prostaglandin in glomerular physiology in man. 相似文献
10.
J. Morley M.A. Bray R.W. Jones D.H. Nugteren D.A. van Dorp 《Prostaglandins & other lipid mediators》1979,17(5):729-736
The ability of partially purified human and guinea-pig haematogenous cell populations, when cultured in vitro, to metabolise arachidonic acid (AA) has been studied. Supernatants from 24 hour cell culture have been subjected to analysis for products of AA metabolism by gas chromatography with electron-capture detection.The cell types studied were human peripheral blood monocytes (both glass adherent and non-adherent), neutrophils, eosinophils and leukemic leucocytes; thoracic duct lymphocytes and lung alveolar macrophages. From the guinea-pig, induced and non-induced macrophage or neutrophil enriched peritoneal exudate populations, lymph node cells, peritoneal eosinophils and peripheral blood platelets were examined. Supernatants were assayed for the presence of PGE2, PGD2, PGF2α, TXB2 and 6-keto-PGF1α. In all types studied PGE2 and TXB2 were the major products formed. The identification of PGE2 and TXB2 was confirmed by GC/MS with multiple ion monitoring.The results have been compared with other reports and their possible significance discussed in relation to the proposed role of prostaglandins as mediators and modulators in immunopathology. 相似文献
11.
Isolated perfused sensitized guinea pig hearts release relatively larhe amounts of radioimmunologically measurable thromboxane B2 (TXB2) as well as smaller amounts of prostaglandins (PGs) after antigenic challenge. Using thin layer chromatography the major PG released was shown to co-chromatograph with PGD2, while smaller amounts of immunoreactive PGF2α were found. The TX-synthetase inhibitor imidazole (100 μg/ml) significantly decreased TXB2 release and simultaneously increased PG release during cardiac anaphylaxis. On the other hand, the β-sympathomimetic drug isoproterenol decreased both TXB2 and PG release from the anaphylactic hearts. While isoproterenol significantly diminished anaphylactic coronary flow reduction, imidazole was without effect in this respect. PGD2 (0.5 μ/min and 5.0 μg/min) infused intraaortally into non-sensitized guinea pig hearts reduced coronary flow dose-dependently. These results are compatible with the view that release of TX and PGs might contribute to coronary flow reduction in cardiac anaphylaxis. 相似文献
12.
Effects of 10 ppm nitrogen dioxide (NO2) exposure on the contents of prostaglandins (PGs) and thromboxane (TX) B2 in broncho-alveolar lavage (BAL) of rats were studied. In the BAL of normal rats, the amounts of PGs and TXB2 in the whole lavage were 6-keto-PGF1α (38.0 ± 6.4 ng) > TXB2 (11.8 ± 4.0 ng) > PGF2α (5.7 ± 1.6 ng) PGE (0.5 ± 0.3 ng). Rats were exposed to NO2 for 1, 3, 5, 7 and 14 days. The NO2 exposure decreased in the level of 6-keto-PGF1α by about 35% throughout the exposure. The level of TXB2 was higher in the day 5 exposure group (155%). The contents of PGF2α and PGE first, decreased and then transiently increased on days 3 and 5. PG 15-hydroxy-dehydrogenase activity of lung homogenate decreased correspondingly on day 3 and 5. Then the contents PGF2α and PGE decreased on day 7 and 14.6-keto-PGF1α and TXB2 are stable metabolites of PGI2, a strong bronchorelaxant and TXA2, a strong bronchoconstrictor respectively. Therefore the results suggested that the decrease in 6-keto-PGF1α, a major prostanoid in the BAL and the increase in TXB2 may correlate with broncho constriction by NO2 exposure. 相似文献
13.
Lidia Sautebin Hans Kindahl Maria Kumlin Elisabeth Granstrm 《Prostaglandins & other lipid mediators》1985,30(3):435-456
Conjugates of prostaglandins and thromboxanes with tritium labeled amino acids were prepared and employed as labeled ligands in porstaglandin and thromboxane radioimmunoassays. Assays for PGF2α, 15-keto-13, 14-dihydro-PGF2α, TXB2 and 15-keto-13, 14-dihydro-TXB2 were evaluated in comparative studies using either these heterologous ligands or the corresponding homologus tritiated eicosanoid as tracers. Binding properties for the respective antibodies were found to be similar using either tracer.Three biological studies were also conducted, viz. study of the release of TXB2 during collagen induced platelet aggregation, of 15-keto-13, 14-dihydro-TXB2 during guinea pig pulmonary anaphylaxis, and of PGF2α (measured as 15-keto-13, 14-dihydro-PGF2α in peripheral plasma) during bovine luteolysis. The analyses gave comparable results using either the heterologous or the homologous assay.Thus, this type of labeled prostanoid conjugates may serve as a convenient alternative to homologous tracers in radioimmunoassay. Heterologous tracers may even in certain cases provide the only simple solution to the problem of preparing a labeled ligand of high specific activity. 相似文献
14.
S. Nigam R. Becker U. Rosendahl J. Hammerstein C. Benedetto M. Barbero T.F. Slater 《Prostaglandins & other lipid mediators》1985,29(4):513-528
Peripheral plasma concentrations of 6-keto-PGF1α and TXB2 were measured in patients with benign and malignant tumours of the breast, in patients with nongynecological disease,a nd in healthy female controls. The values were significantly higher in female patients with maligants tumours of the breast than in healthy controls (146 ± 28 vs 13 ± 2.5 pg/ml for 6-keto-PGF1α p<0.01 and 78 ± 17 vs 11 ± 2 pg/ml for TXB2, p<0.01). Benign tumours of the breast were also associated with significantly raised plasma levels of 6-keto-PGF1α and TXB2 compared to normal controls (52 ± 5 vs 13 ± 2.5 pg/ml for 6-keto-PGF1α, p < 0.01 and 26 ± 5 vs 11 ± 2 pg/ml for TXB2, p < 0.05). The high levels of 6-keto-PGF1α and TXB2 were not found to be correlated with clinical and histopathological data. The surgical removal of the primary tumour has apparently no effect on the plasma concentration of 6-keto-PGF1α and TXB2 over a follow-up period of 9 days after operation. The lack of alterations in the ratio of TXB2: 6-keto-PGF1α in the cancer patients and other subjects studied before and after surgery is indicative of the regulatory power of metabolic systems to preserve the homeostatic balance. 相似文献
15.
Raymond F. Anton Cleatus Wallis Carrie L. Randall 《Prostaglandins & other lipid mediators》1983,26(3):421-429
A focused microwave fixation technique was tested for use in determining basal PGE and thromboxane B2 levels of mouse brain. Focused microwave irradiation (3.5 Kw/0.4 sec) to the head of C3H mice produced basal values of PGE and TXB2 which were five-fold less than those in animals killed by decapitation. Indomethacin (10 mg/kg) pretreatment blocked the decapitation rise in PGE and TXB2 levels and gave values similar to focused microwave irradiation. Indomethacin pretreatment combined with microwave fixation did not reduce PG levels more tham microwave treatment alone. When microwave fixation was used, there was no difference in regional (cerebral cortex, whole cerebellum, midbrain, hypothalamus) levels of either PGE or TXB2. However, PGE levels were significantly higher than TXB2 in all regions. After decapitation there was a greater increase in TXB2 than PGE. The cerebellum produced less PGE and TXB2 after decapitation compared to the other regions. Our results confirm the usefulness of the focused microwave irradiation technique for examining basal prostaglandin levels in mouse brain. 相似文献
16.
Continuously superfused rat anterior pituitary cells were used to study the effects of exogenous prostaglandins (PGs) and thromboxanes (TXz) on the secretion of prolactin (PRL). No change in hormone release was observed upon superfusion with TXB2 (10−5M) or the TX synthesis inhibitor, imidazole (1.5 mM). PGs A2, B2, d2, e1, e2, f1α, F2α, and endoperoxide analogs, U-44069 and U-46619, also had no effect on PRL secretion (all at 10−5M), In contrast 10−5M PGI2 was repeteadly found to stimulate PRL release to a level at least 125% above control, while producing no apparent change in the amount of hormone secreted in response to TRH. Somatostatin (SRIF), at a dose of 10−M, maximally inhibited TRH-induces PRL output, but failed to alter the PRL response to PGI2. These studies indicate that PGI2 may have a direct effect on the anterior pituitary to modify PRL secretion. 相似文献
17.
Jean H.M. Feyen Gertjan van der Wilt Peter Moonen Alfredo Di Bon Peter J. Nijweide 《Prostaglandins & other lipid mediators》1984,28(6):769-781
The effects of parathyroid hormone (PTH), dihydroxycholecalciferol (1,25-(OH)2 D3), thrombin, epidermal growth factor (EGF) and 12-o-tetradecanoylphorbol-13-acetate (PMA) on the biosynthesis and release of arachidonic acid metabolites were studied in primary cultures of osteoblast-like cells isolated from 18-day-old chick embryo calvaria. Cells were labelled with (14C)-arachidonic acid for 30 h. The radioactive eicosanoids were extracted from the cell culture media after a further 30 h stimulation period and analysed on a PRP-1 column by HPLC. The radioactive products were characterized by co-elution of (3H) standard prostanoids. Osteoblasts showed a basal release of the prostanoids 6-keto-PGF1α, TXB2, PGF2α, PGE2, PGD2 and PGB2, the latter being the most abundant one. Indomethacin (10−5 M) effectively inhibited the basal release, but not that of an as yet unidentified compound. The release of prostanoids was stimulated by PTH (2 U/ml), thrombin (0.4 NIH/ml), EGF (50 ng/ml) and PMA (25 ng/ml), the latter being by far the most potent one. 1,25-(OH)2D3 was found to slightly inhibit the prostanoid release. These results indicate: (1) primary cultures of osteoblasts synthesize several prostaglandins, thromboxane B2 and one unidentified product. (2) the action on bone of PTH and the various drugs tested may be, at least partly, mediated by an increased prostaglandin production by osteoblasts. Clearly this does not apply to 1,25-(OH)2D3. 相似文献
18.
Role of prostaglandins in calcium-induced corticosteroid secretion by isolated frog interrenal gland
I. Lihrmann C. Delarue F. Homo-Delarche P. Netchitailo F. Leboulenger H. Vaudry 《Prostaglandins & other lipid mediators》1986,32(1):127-131
The role of prostaglandins (PGs) in calcium-induced corticosteroid secretion by frog adrenal (interrenal) gland examined
using a perifusion technique. Increasing concentrations of CaCl2 (4–10 mM) stimulated in a dose-dependent manner aldosterone, PGE2 and 6-keto-PGF1α production, whereas TXB2 was not affected. The kinetics of the adrenal response to CaCl2 indicated that the increase in PG output always preceded that of steroid. Administration of cobalt (4 mM), a calcium-channel inhibitor, blocked the calcium-induced stimulation of PGs and corticosteroids. Infusion of indomethacin (5 × 10−6M), a specific cyclooxygenase inhibitor, significantly decreased the basal production of PGs and steroids, and prevented the stimulatory effect of CaCl2 (6 mM). Infusion of the calcium ionophore A 23187 (10−6 M), for 20 min, induced a marked stimulation of PG and steroid production. Taken together, these data support the notion that biosynthesis of prostaglandins is associated with calcium-induced corticosteroid secretion in frog adrenal cells. 相似文献
19.
The effects of alterations in extracellular calcium concentration on prostaglandin (PGE) and thromboxane (TXB2) syntheses were studied in isolated epithelial cells from the urinary bladder of the toad, Bufo marinus. In epithelial cells prepared using collagenase, basal iPGE synthesis was greater than iTXB2 synthesis. Increasing extracellular calcium from zero to 1 mm increased iPGE synthesis and decreased iTXB2 synthesis equivalently such that total conversion of endogenous arachidonate to these two metabolites was unaltered. Vasopressin stimulated iPGE and iTXB2 syntheses when the incubation buffer contained 1 mm calcium but had no effect in the presence of 0.4 μm calcium. In contrast, using an EDTA isolation method, basal iPGE and iTXB2 syntheses were equal in the presence of zero calcium. Increasing extracellular calcium concentration to 1 mm caused a greater enhancement in iTXB2 synthesis compared to iPGE. Increasing extracellular calcium to 2 mm was associated with a decline in iPGE and iTXB2 syntheses back to the levels observed with no calcium added to the medium. The effect of increasing the calcium concentration was greater in phosphate than in bicarbonate buffer. In a Tris buffer the effect of altered calcium was almost completely abrogated. These studies demonstrate that the choice of buffer and alterations in extracellular calcium concentration differentially alter basal arachidonic acid metabolism to prostaglandins and thromboxane in isolated toad urinary bladder cells. The results suggest that there may exist several endogenous pools of arachidonic acid which are differentially influenced by calcium. Furthermore, the pool sensitive to vasopressin has an absolute requirement for calcium. 相似文献
20.
Paulette Mehta Jawahar Mehta Fulton Crews Louis Roy Nancy Ostrowski Christine Horalek 《Prostaglandins & other lipid mediators》1982,24(6):743-749
There is growing evidence that blood vessels generate TXA2 in addition to PGI2. We examined effluents from continously perfused human umbilical vein and supernatants from umbilical vein rings for TXB2 and 6-keto-PGF1α measurements (stable metabolites of TXA2 and PGI2, respectively). TXB2 and 6-keto-PGF1α were identified in all samples. 6-keto-PGF1α to TXB2 ratio was higher in intact vein effluents than in the venous ring supernatants (112:1 and 28:1, respectively, P<0.01). Arachidonate stimulation increased 6-keto-PGF1α and TXB2 levels similarly in the intact vein effluent. In contrast, stimulation of the venous rings resulted in a relatively larger increase in TXB2 than in 6-keto-PGF1α. This caused 6-keto-PGF1α to TXB2 ratio to decline (p<0.01). The identity of TXB2 was confirmed in several different ways. These data suggest that 1) human umbilical veins produce TXA2 in addition to PGI2, 2) TXA2 release is more by venous rings than by the intact vein probably reflecting contribution from non-endothelial layers, and 3) arachidonate stimulation causes relatively greater release of TXA2 than of PGI2 from the venous rings, whereas release of PGI2 and TXA2 is similar from the intact vein. 相似文献