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1.
The use of mercaptoethanol in the assay of rat kidney 15-hydroxyprostaglandin dehydrogenase (PGDH) was found to have minimal effect on activity assayed with the spectrophotometric and substrate loss assays. However, mercaptoethanol appeared to inhibit PGDH when assayed by thin-layer chromatography, based upon conversion of 3H-PGE1 to 15-keto-3H-PGE1. Mercaptoethanol reacted with 15-keto-PGE1 to alter its chromatographic mobility and to suppress the U.V. absorption spectrum of 15-keto-PGE1. The implication of the use of ME in radiometric assays is discussed. 相似文献
2.
Frances A. Kimball Kenneth T. Kirton Lillian J. Wyngarden 《Prostaglandins & other lipid mediators》1975,10(5):853-864
Myometrial low speed supernatant prepared from non-pregnant rhesus uteri was incubated with 3H-Prostaglandin (PG)E1 with or without addition of unlabelled prostaglandins. The uptake of 3H-PGE1 was inhibited in a dose dependent fashion by PGE2>PGE1>PGA1>PGF2α=PGA1>PGB1=PGB2≥PGD2. PGE1 metabolites inhibited 3H-PGE1 binding in the following order: 13,14-dihydro-PGE1>13,14-dihydro-15-keto-PGE1=15-keto-PGE1. The specific binding of 3H-PGE1 and 3H-PGF2α was similarly affected by the temperature and time of incubation. Equilibrium binding constants determined using rhesus uteri obtained during the luteal phase of the menstrual cycle indicate the presence of high affinity PGE1 binding sites with an average (n=3) apparent dissociation constant of 2.2 × 10−9M and a lower affinity PGE1 binding site with a Kd ≅ 1 × 10−8M. No high affinity — low capacity 3H-PGF2α sites could be demonstrated.Relative uterine stimulating potencies of some natural prostaglandins and prostaglandin analogs tested after acute intravenous administration in mid-pregnant rhesus monkeys corresponded with the PGE1 binding inhibition of the respective compound. The uterine stimulating potencies of the prostaglandin analogs tested were: (15S)-15-methyl-PGE2=16,16-dimethyl-PGE2>17-phenyl-18,19,20-trinor-PGE2>16 phenoxy-17,18,19,20-tetranor-PGF2α=PGE2=PGE1=(15S)-15-methyl-PGF2α>PGF2α. 相似文献
3.
Studies of 3H-PGE1 binding in hamster uterus were conducted with tissue fractions isolated after incubation of tissue slices in media containing 3H-PGE1, or in a total
system, in which 3H-PGE1 was incubated directly with isolated uterine tissue fractions. Bound 3H-PGE1 was seperated from unbound 3H-PGE1 by gel column chromatography or by treatment with activated charcoal. The effects of the non-ionic detergent Triton X-100 on binding were measured in both incubation systems.The presence of a specific binding-protein for 3H-PGE1 in hamster myometrium was demonstrated
. The binding-protein was associated with a membrane fraction of the myometrial cell and was dependent on the integrity of membrane structure for binding specificity. The binding-protein was stabilized by association with its ligand, 3H-PGE1, and binding was irreversible
. 相似文献
4.
Ch. V. Rao 《Prostaglandins & other lipid mediators》1975,9(4):579-584
The specific binding of 3H-prostaglandin E1 (3H-PGE1) to bovine corpus luteum cell membranes was not affected by cholesterol or various progestins at concentrations of up to 9.0 × 10−6M. At concentrations above 2.5 × 10−6M; estrone, 17β-estradiol (but not 17α-estradiol or 17β-estradiol glucuronide), estriol, equilin, D-equilenin, 17-ethynyl estradiol, diethylstilbestrol, cortisol, corticosterone, deoxycorticosterone and aldosterone inhibited specific binding of 3H-PGE1. On the other hand, testosterone and dihydrotestosterone (DHT) (but not androstenedione) significantly enhanced 3H-PGE1 binding. These findings permitted the following correlations between steroid structure and modulation of 3H-PGE1 binding: steroids with a free phenolic ring and a 17β-hydroxyl or 17-keto group or C-21 steroids with a C-20 ketone and a C-21 hydroxy group decrease, whereas C-19 steroids with a C-17 hydroxy group enhance specific binding of 3H-PGE1. PGE receptors are heterogeneous with respect to affinity for 3H-PGE1. The steroids that decreased 3H-PGE1 binding caused a lowering to a complete loss of low affinity PGE receptors. Steroids that increased 3H-PGE1 binding caused appearance of new low affinity PGE receptors. Association rate constants for 3H-PGE1 binding were decreased by 17β-estradiol (61%) and increased by DHT (59%). 相似文献
5.
Ch.V. Rao 《Prostaglandins & other lipid mediators》1975,9(4):569-578
The specific binding of 3H-prostaglandin E1 (3H-PGE1) to bovine corpus luteum cell membranes was not affected by cholesterol or various progestins at concentrations of up to 9.0 × 10−6M. At concentrations above 2.5 × 10−6M; estrone, 17β-estradiol (but not 17α-estradiol or 17β-estradiol glucuronide), estriol, equilin, D-equilenin, 17-ethynyl estradiol, diethylstilbestrol, cortisol, corticosterone, deoxycorticosterone and aldosterone inhibited specific binding of 3H-PGE1. On the other hand, testosterone and dihydrotestosterone (DHT) (but not androstenedione) significantly enhanced 3H-PGE1 binding. These findings permitted the following correlations between steroid structure and modulation of 3H-PGE1 binding: steroids with a free phenolic ring and a 17β-hydroxyl or 17-keto group or C-21 steroids with a C-20 ketone and a C-21 hydroxy group decrease, whereas C-19 steroids with a C-17 hydroxy group enhance specific binding of 3H-PGE1. PGE receptors are heterogeneous with respect to affinity for 3H-PGE1. The steroids that decreased 3H-PGE1 binding caused a lowering to a complete loss of low affinity PGE receptors. Steroids that increased 3H-PGE1 binding caused appearance of new low affinity PGE receptors. Association rate constants for 3H-PGE1 binding were decreased by 17β-estradiol (61%) and increased by DHT (59%). 相似文献
6.
Yu-Hsiang Yu Yi-Cheng Chang Tseng-Hsiung Su Jiun-Yi Nong Chao-Chin Li Lee-Ming Chuang 《Journal of lipid research》2013,54(9):2391-2399
Adipocyte differentiation is a multistep program under regulation by several factors. Peroxisome proliferator-activated receptor γ (PPARγ) serves as a master regulator of adipogenesis. However, the endogenous ligand for PPARγ remained elusive until 15-keto-PGE2 was identified recently as an endogenous PPARγ ligand. In this study, we demonstrate that zinc-containing alcohol dehydrogenase 2 (ZADH2; here termed prostaglandin reductase-3, PTGR-3) is a new member of prostaglandin reductase family that converts 15-keto-PGE2 to 13,14-dihydro-15-keto-PGE2. Adipogenesis is accelerated when endogenous PTGR-3 is silenced in 3T3-L1 preadipocytes, whereas forced expression of PTGR-3 significantly decreases adipogenesis. PTGR-3 expression decreased during adipocyte differentiation, accompanied by an increased level of 15-keto-PGE2. 15-keto-PGE2 exerts a potent proadipogenic effect by enhancing PPARγ activity, whereas overexpression of PTGR-3 in 3T3-L1 preadipocytes markedly suppressed the proadipogenic effect of 15-keto-PGE2 by repressing PPARγ activity. Taken together, these findings demonstrate for the first time that PTGR-3 is a novel 15-oxoprostaglandin-Δ13-reductase and plays a critical role in modulation of normal adipocyte differentiation via regulation of PPARγ activity. Thus, modulation of PTGR-3 might provide a novel avenue for treating obesity and related metabolic disorders. 相似文献
7.
《Prostaglandins and medicine》1980,4(4):227-237
Cyclooxygenase products of arachidonic acid metabolism in the plasma of normal rabbits and animals bearing the VX2 carcinoma were separated by high performance liquid chromatography and the effluent fractions assayed by serologic methods. The products measured were 6-keto-PGFlα, thromboxane B2, PGE2, PGF2α, 13,14-dihydro-PGE2, 13,14-dihydro-15-keto-PGE2, 15-keto-PGE2, and 13,4-dihydro-15-keto-PGF2α. In hypercalcemic, tumor-bearing rabbts, the plasma concentrations o 13,14-dihydro-15-keto-PGE2 and 13,14-dihydro-15-keto-PGF2α were markedly elevated (in the range of 0.5 to 16 ng/ml). Previously unmeasured 6-keto-PGF1α, thromboxape B2, 13,14-dihydro-PGE2 and 15-keto-PGE2 were not found in high concentrations in the plasma of tumor-bearing rabbits. These results add further support to our conclusion that the VX2 tumor produces hypercalcemia in the host by a mechanism which utilizes PGE2, rather than a subsequent metabolite of this prostaglandin, as the mediator between the neoplasm and bone. 相似文献
8.
D.P. Cardinali M.N. Ritta N.S. Speziale M.F. Gimeno 《Prostaglandins & other lipid mediators》1979,18(4):577-589
Incubated bovine pineal glands released prostaglandin E- and prostaglandin F-like material (304 ± 20 and 582 ± 56 pg/mg dry tissue wt/h, respectively) and the release was increased 2.2 2.9-fold by adding 10−4–10−6M of norepinephrine to the medium. Binding assays revealed the existence of high affinity binding of 3H-prostaglandin E2 (3H-PGE2) and 3H-prostaglandin F2α (3H-PGF2α) in low speed supernatants of pineal homogenates. Binding was increased by increasing Ca++ concentration in medium up to 2 mM, was heat-labile and was depressed following incubation with trypsin. In subcellular fractionation studies maximal 3H-PG binding was found in the 27000 × g pellet. Scatchard analysis of 3H-PGE2 binding revealed the presence of a single population of binding sites with a Kd= 1.2 nM and a binding site concentration of 1–2 pmoles/g protein. A single population of binding sites for 3H-PGF2α was also detected with a Kd= 1.7 nM and a similar binding site concentration. Non-radioactive PGE1 and PGE2 were almost equally effective to compete for 3H-PGE2 binding sites (ED50= 5 and 2 nM, respectively). Unlabeled PGF2 was relatively ineffective to compete for 3H-PGE2 binding (ED50>1000 nM) but displaced effectively 3H-PGF2α binding (ED50= 1.2 nM). 相似文献
9.
10.
Ch.V. Rao 《Prostaglandins & other lipid mediators》1973,4(4):567-576
The cell membranes exhibited specific binding to 3H-prostaglandin E1 (3H-PGE1) and 125I-human chorionic gonadotropin (125I-HCG). Unlabeled PGE1,PGE2 (1.4 × 10?7M), PGF1α and PGF2α (1.4 × 10?5M) decreased 3H-PGE1 binding by more than 80%. The binding of 125I-HCG was completely inhibited by 5 × 10?8M unlabeled HCG. However, the unlabeled PGE1 (1.15 × 10?6M) and HCG (8.4 × 10?7M) had no effect on 125I-HCG and 3H-PGE1 binding respectively. A PG antagonist, 7-oxa-13-prostynoic acid, inhibited only 3H-PGE1 binding but not 125I-HCG binding. These results suggest the presence of specific receptors for PGE1 and HCG in the cell membranes and that the binding occurs either at two different sites on the same receptor or that each binds to a “different” receptor molecule. 相似文献
11.
A direct comparison of the relative potencies of the prostaglandins PGI2 and 6-kto-PGE1 to induce renin release was made in the isolated rat kidney, which was perfused with a synthetic medium at constant perfusion pressure.Both prostaglandins stimulated renin release in a dose-dependent manner (0.01 to 1 μM) and with equal potency.Also in the isolated rabbit kidney, PGI2 and 6-keto-PGE1 had the same potency to induce renin release at 1 μM final concentration.Following infusion of 6-keto-PGE1 a small increase of vascular resistance in the rat kidney was observed, whereas in the rabbit kidney no constrictor effect was seen.When perfusate of PGI2 or 6-keto-PGE1-infused rat kidneys were tested for antiaggregatory activity in the ADP induced aggregation of human platelets and compared with authentic standards, the results showed 6-keto-PGE1 passes the kidney essentially unchanged, whereas only 25–40% of the infused PGI2 appear in the venous perfusates, as judged from the recovery of antiaggregatory activity.Analysis of venous perfusates from 3H-PGI2 infused kidneys by high performance liquid chromatography indicates that about 25% of the infused PGI2 remains intact, a major portion of the perfused radioactivity was identified as 6-keto-PGF1α by combined gaschromatography-mass-spectrometry (19).We conclude that the renin-stimulating effect of PGI2 is not secondary to its metabolism to 6-keto-PGE1, as has been suggested in the literature (8). 相似文献
12.
《Prostaglandins and medicine》1979,2(4):277-284
Since prostaglandin E1 (PGE1) is known to have a beneficial effect in hemorrhagic shock, a biologically active derivative of PGE1, 6-keto-PGE1, was examined for its effect on traumatic shock in rats. In sham-operated rats, infusion of 6-keto-PGE1, at a rate of 250 ng/kg/min intravenously decreased arterial blood pressure by 23 mm Hg at 5 hr. In rats subjected to Noble-Collip drum trauma, infusion of 6-keto-PGE1, starting 15 min after the trauma, significantly improved the survival time from 1.0 ± 0.1 hr to 2.6 ± 0.3 hr compared to rats given only the vehicle (i.e., Tris buffer). The improved survival was accompanied by a diminished plasma accumulation of the cardiotoxic peptide, myocardial depressant factor (MDF), and the lysosomal protease cathepsin D. 6-keto-PGE1 also exerted a direct lysosomal stabilizing effect in isolated cat liver lysosomes, as well as reducing cardiac afterload in rats. It is concluded that 6-keto-PGE1 protects in traumatic shock by hemodynamic as well as cytoprotective actions. 相似文献
13.
Preliminary studies indicate the presence of PGF2α specific binding sites in membrane fractions prepared from equine corpora lutea. The equilibrium binding data indicate an apparent dissociation constant of 3.2 × 10?9M and the concentration of binding sites of ~0.1 pmoles/mg membrane protein. Competition of several natural prostaglandins for equine luteal PGF2α specific binding sites indicates specificity for the 9α-hydroxyl moiety and the 5,6-cis doublebond. Significant increases in relative binding affinities were demonstrated for PGF2α analogs with a phenyl ring introduced at carbons 16 or 17. Specific PGF2α binding was demonstrated in corpora lutea collected at known stages of the estrous cycle. There was no pattern in these values based on the stage of the cycle. While specific 3H-PGE1 binding could be demonstrated, no high affinity sites could be quantitated. 3H-PGE1 binding appeared unaffected by changes in temperature or time of incubation, whereas PGF2α specific binding was significantly modified by both these factors. 相似文献
14.
A.L. Gimeno M. Chaud A. Bonacossa A.M. Franchi M.F. Gimeno 《Prostaglandins & other lipid mediators》1983,26(4):663-676
Dose-response curves for several prostaglandins (PGI2; PGD2; PGF2 and PGE2); BaCl2 or prostaglandin metabolites (15-keto-PGF2α; 13, 14-diOH-15-keto-PGF2α; 6-keto-PGF1α and 6-keto-PGE1 in quiescent (indomethacin-treated) uterine strips from ovariectomized rats, were constructed. All PGs tested as well as BaCl2, triggered at different concentrations, evident phasic contractions. Within the range of concentrations tested the portion of the curves for the metabolites of PGF2α was shifted to the right of that for PGF2α itself; the curve for 6-keto-PGF1α was displaced to the right of the curve for PGI2 and that for 6-keto-PGE1 to the left.It was also demonstrated that the uterine motility elicited by 10−5 M PGF2α and its metabolites was long lasting (more than 3 hours) and so it was the activity evoked by PGI2; 6-keto-PGF1α and BaCl2, but not the contractions following 6-keto-PGE1, which disappeared much earlier. The contractile tension after PGF2α; 15-keto-PGF2α; 13, 14-diOH-15-keto-PGF2α and PGI2, increased as time progressed whilst that evoked by 6-keto-PGF2α or BaCl2 fluctuated during the same period around more constant levels.The surprising sustained and gradually increasing contractile activity after a single dose of an unstable prostaglandin such as PGI2, on the isolated rat uterus rendered quiescent by indomethacin, is discussed in terms of an effect associated to its transformation into more stable metabolites (6-keto-PGF1α, or another not tested) or as a consequence of a factor which might protects prostacyclin from inactivation. 相似文献
15.
Patrick Y-K Wong Kafait U. Malik Dominic M. Desiderio John C. McGiff Frank F. Sun 《Biochemical and biophysical research communications》1980,93(2):486-494
Metabolism of [9-3H]-PGI2 was studied in the isolated Tyrode's perfused rabbit liver. Five products, four radioactive and one non-radioactive, were identified in the perfusate: 19-hydroxy-6-keto-PGF1α, 6-keto-PGF1α, dinor-6-keto-PGF1α, pentanor PGF1α and a 6-keto-PGE1-like substance. The first two, 19-hydroxy-6-keto-PGF1α and 6-keto-PGF1α, represented 5% and 45% respectively, of the total radioactivity; the last two accounted for 39%. The presence of dinor and pentanor derivatives of 6-keto-PGF1α indicated that β -oxidation and oxidative-decarboxylation occurs in the liver as the major metabolic pathway of PGI2. One non-radioactive metabolite which co-migrated with authentic 6-keto-PGE1 was found to inhibit platelet aggregation, having a potency similar to authentic 6-keto-PGE1, and its effect can be eliminated by boiling and by alkali treatment. This metabolite, having similar Rf value on TLC and biological behavior as 6-keto-PGE1, may arise from oxidation of 6-keto-PGF1α via the 9-hydroxyprostaglandin dehydrogenase pathway, as suggested by recovery of tritiated water in the aqueous phase of the perfusate. This material, a potent inhibitor of platelet aggregation, may arise from PGI2 or its hydrolysis product, 6-keto-PGF1α. 相似文献
16.
Dr. David P. Penney J. Olson G. V. Marinetti S. Vaala K. Averill 《Cell and tissue research》1973,146(3):309-317
Summary To determine whether or not prostaglandins enter adrenocortical parenchymal cells,3H-PGE1 was injected intravenously into rats. In histological preparations, grains denoting activity were noted in intracellular
lipid droplets and nuclei and in sinusoids. At the fine structural level, activity was observed in lipid droplets, mitochondria,
the agranular endoplasmic reticulum, nuclei and the plasma membrane. Biochemical lipid analyses of the adrenals revealed activity
in the cholesterol and cholesterol ester fractions. Large amounts of unaltered3H-PGE1 and its degradation products were also present. Compared to the liver, the adrenal was more effective in degrading prostaglandin,
when expressed on a weight basis. The possible roles of the organelles in PGE1 degradation and in prostaglandin-related hormone synthesis are discussed.
Supported by N.I.H. Grants AM-09561 and RR-05403. 相似文献
17.
A charcoal adsorption method was developed to measure specific prostaglandin binding in low speed supernates of hamster myometrial homogenates. This method was used to characterize and quantitate PGE1-specific binding. The equilibrium binding constants and the concentration of specific PGE1 binding sites were determined during the hamster estrous cycle. The apparent association constant for 12 different preparations was 1.16 ± 0.08 × 109M−1. The concentration of PGE1 specific binding sites was significantly higher on Days 2 and 3 of the estrous cycle than it was on Days 1 or 4. The competition for PGE1 binding sites by PGE2, PGF2α, PGA1 and various PGE1 metabolites and derivatives was measured in hamster myometrial homogenates. Relative affinities of the natural prostaglandins for the PGE1 binding sites, calculated by parallel line assay, were: PGE2>PGE1>PGA1>PGF2α. For PGE1 metabolites the relative affinities were: PGE1>13,14-dihydro-PGE1>13,14-dihydro-15-keto-PGE1>15-keto-PGE1. For the analogs and derivatives the compounds tested ranked as: 16,16-dimethyl-PGE1≥PGE1>PGE1 methyl ester>17-phenyl-18,19,20-trinor-PGE1>15(S)15-methyl-PGE1 methyl ester. Arachidonic acid, bis-homo-γ-linolenic acid and 7-oxa-13 prostynoic acid had relative affinities ≥0.1 compared to PGE1=100. Indomethacin had a relative affinity of 0.4 compared to PGE1. 相似文献
18.
Binding of biologically active 3H-PGE2 to particulate fractions of porcine gastrointestinal mucosa and muscle was investigated. Specific binding activity was detected in the 2500 xg and 30,000 xg sedimentation fractions of mucosa from esophagus, fundus, antrum, duodenum, ileum and colon, as well as in serosal muscle taken from the antrum, ileum, and colon. Optimal binding (> 40 fmol/mg protein) was observed in the 30,000 xg fraction of fundic mucosa incubated at pH 5.0. The characteristics of 3H-PGE2 binding were variable in the remainder of the gastrointestinal tract although binding in these tissues was significantly less (0.2 to 15 fmol/mg protein) than that observed in the fundic mucosa. These data suggest that the cellular and/or subcellular site of PG binding is not uniform throughout the gastrointestinal tract. In fundic mucosa removal of the surface epithelial layer by scraping did not significantly alter the total binding activity for PGE. This result suggests that in gastric secretory mucosa optimal binding activity for PGE2 occurs within the gastric pits deep to the surface epithelium. 相似文献
19.
Nargis A. Alam Patricia Clary P.T. Russell 《Prostaglandins & other lipid mediators》1973,4(3):363-370
3H-Prostaglandin E1 metabolism has been assessed in 15,000 × g supernatant preparations from human placentas of normal and toxemic pregnancies. The ability of the toxemic tissue to metabolize 3H-PGE1 is depressed in direct relationship to the severity of the disease. This impaired metabolism of prostaglandin E1 appears to be a biochemical characteristic of the toxemia of pregnancy. 相似文献
20.
A.M. Franchi A. Faletti M.F. Gimeno A.L. Gimeno 《Prostaglandins & other lipid mediators》1985,29(6):953-960
The present experiments report the effects of estradiol or of progesterone on the activity of 15-prostaglandin-dehydrogenase (PGDH) in the uterus of spayed rats. When the substrate was PGF2α the treatment with progesterone (4 mg.day−1, two days) or with estradiol-17-beta (0.5 ug + 1 ug) did not show any effect on the activity of the enzyme. On the contrary, uteri from ovariectomized rats injected with a higher dose of estradiol- 17-beta (0.5 ug + 50 ug) exhibited a significant increment. When the substrate was PGE2, progesterone failed again to modify the enzyme activity, whereas estradiol, both at a low and at a high doses, enhanced significantly the uterine PGDH activity. The possibility of two different PGDHs for each PG and the role of estradiol in enhancing PGE2 catabolism into 15-keto- PGE2 as a mechanism subserving the effect of estrogens on the output of this PG in the rat uterus, are discussed. 相似文献