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1.
Acetylsalicylic acid (ASA), indomethacin, sodium meclofenamate (FEN), phenylbutazone (PB), phloretin phosphates (PP), SC-19220, and diethylcarbamazine citrate (DECC) were screened against histamine, 5-hydroxytryptamine (5-HT), bradykinin, acetylcholine, and prostaglandins (PG) E1, E2, and F2α to determine their specificity in antagonizing PG's on the bovine pulmonary vein. PG E2 relaxed the smooth muscle preparation at low concentrations and induced contraction at higher concentrations. PG E1 consistently evoked dose-related relaxations, whereas PG F2α contracted the bovine pulmonary vein. Studies with inhibitors suggest that the different actions of prostaglandins could be mediated through different receptors. Sodium meclofenamate and PP dimer blocked PG E2-induced contractions, whereas relaxations were not blocked. DECC inhibited the relaxant effect of PG E2. DECC also antagonized histamine, 5-HT, and PG F2α, suggesting the drug is rather non-specific. Phenylbutazone antagonized the actions of both PG E2 and PG F2α on the bovine pulmonary vein. By classifying receptors by antagonism the bovine pulmonary vein appears to contain PG E2 (PP-type), PG E2 (FEN-type), PG E2 (PB-type), and PG F2α (PB-type) receptors. An absence of SC-type PG-receptors is noted. 相似文献
2.
Ronald I. Clyman Louise Wong Michael A. Heymann Abraham M. Rudolph 《Prostaglandins & other lipid mediators》1978,15(2):325-331
The relative potencies of the prostaglandins A1, A2, E1, E2, F2α and their 15-keto-, 15-keto-13,14-dihydro-, and 13,14-dihydro-metabolites were investigated on isolated lamb ductus arteriosus preparations contracted by exposure to elevated PO2. All the prostaglandins (except PGF2α and its 15-keto-metabolites) relaxed the tissue. However, only PGE1, E2, and their 13,14-dihydro-metabolites, were effective at concentrations below 10−8 M. Therefore, events that alter metabolism of circulating PGs in the perinatal period may have significant effects on the relative patency or closure of the ductus arteriosus. 相似文献
3.
The release of prostaglandin E2 and F2α, thromboxane B2 and 6-keto-prostaglandin F1α was measured in isolated human placental cotyledons perfused under high- and low-oxygen conditions. Also the effect of reoxygenation on prostaglandin production was studied. During the high-oxygen period, prostaglandin E2 accounted for 44 % and 6-keto-prostaglandin F1α for 28 % of all prostaglandin release, and the rank order of prostaglandin release was E2 > 6-keto-prostaglandin F1α > thromboxane B2 > prostaglandin F2α. Hypoxia had no significant effect on quantitative prostaglandin release, but the ration of prostaglandin E2 to prostaglandin F2α was significantly increased. After the hypoxic period during reoxygenation the release of 6-keto-prostaglandin F1α was significantly decreased, as was the ratio of 6-keto-prostaglandin F1α to thromboxane B2. Also the ratio of the vasodilating prostaglandins (E2, 6-keto-prostaglandin F1α) to the vasocontricting prostaglandins (thromboxane B2, prostaglandin F2α) was decreased during reoxygenation period. With the constant flow rate, the perfusion pressure increased during hypoxia in six and was unchanged in three preparation. The results indicate that changes in the tissue oxygenation in the placenta affect prostaglandin release in the fetal placental circulation. This may also have circulatory consequences. 相似文献
4.
This study establishes some correlations between molecular structure and surface function of six prostaglandins in a model membrane system. Using spread films at the air/water interface, we determined surface pressure and surface potential of PGs A1, A2, E1, E2, F1α and F2α. All the PGs formed films with low pressure (0 to 9 dyne/cm) and relatively low surface potentials (ΔV = 10 to 250 mV). On 0.15 M NaCl, the π and ΔV values were in the order E1 > F1α > A1 > F1α > A1 > F2α = A2 > E2 and F1α > E1 > A1 > A2 > F2α > E2 respectively. Clearly, the cis unsaturation in the carboxylic chain of the PG2 series conferred greater instability to the films, as indicated by the lowest π and ΔV values. Also, members of the PG1 series penetrated films of dipalmitoyl phosphatidyl choline (DPPC) better than PG2 did, the ablest being E1 (Δπ = 12 dyne/cm) and the poorest F2α (Δπ = 2 dyne/cm); penetration of E1 and F2α was independent of the initial pressure (πi) of the DPPC film, whereas with A1 and F1α Δπ decreased as πi increased. The PGs expressed marked discriminating capacities for the electrolyte, as indicated by differences in their π and ΔV responses to Na+ and Ca++ as well as for the lipid, as indicated by different penetration (Δπ values) into DPPC films. 相似文献
5.
Michitaro Nagasawa James Amigo Chan Charles J. Sih 《Prostaglandins & other lipid mediators》1974,8(3):221-230
Prostaglandins E1, F1α and A2 were covalently joined to the surface of Sepharose as carboxamide linkages. The insolubilized prostaglandins were shown to function effectively in the purification of 15(S) -hydroxyprostaglandin dehydrogenase. 相似文献
6.
Michel Lagarde Marc Dechavanne Michel Rigaud Jacqueline Durand 《Prostaglandins & other lipid mediators》1979,17(5):685-705
Radioimmunoassays of platelet prostaglandins E1 and F1α in platelet rich plasma or platelet suspension, demonstrate that both PGE1 and PGF1α are present at higher concentrations than prostaglandins E2 and F2α. Gas chromatography — mass spectrometry determinations of prostaglandins E1 and E2 in resting washed platelets confirm this difference. Lastly, there is a greater incorporation of [1-14C] acetate into prostaglandins E1 and F1α compared to that into prostaglandins E2 and F2α. 相似文献
7.
Effects of prostaglandins e(2) and f(2alpha) on the electrofusion of pea mesophyll protoplasts
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The effects of prostaglandins E2 and F2α on the electrofusion of pea (Pisum sativum cv Ran 1) mesophyll protoplasts were examined. Prostaglandins E2 and F2α influenced electrofusion by lowering the threshold voltage necessary for fusion of dielectrophoretically arranged pairs of protoplasts. The direct current voltage threshold decreased with increasing Ca2+ concentration up to 0.1 millimolar CaCl2 and the effects of prostaglandins E2 and F2α were more pronounced when CaCl2 was present in the medium. Treatment with calcium channel blocker methoxy verapamil did not change the prostaglandin effects, while the addition of ethyleneglycol-bis (β-aminoethyl either)-N,N,N′,N′-tetraacetic acid, which binds free Ca2+, increased the threshold voltage. Influence of prostaglandins E2 and F2α and Ca2+ on the membrane fluidity was investigated by analysis of pyrene fluorescence spectra. The values of the ratio between the maximum fluorescence emission intensities of the excimer and the monomer forms (Iex/Imon) indicated that prostaglandins and Ca2+ decrease the membrane fluidity. It is proposed that electrically evoked displacement of plasmalemma components takes part in the fusion process (U Zimmermann 1982 Biochim Biophys Acta 694: 227-277). We suggest that prostaglandins E2 and F2α facilitate the electrofusion of pea mesophyll protoplasts by changing the fluidity of plasmalemma. 相似文献
8.
Effects of prostaglandins (PGs) E1, E2, F2α and I2 in a wide range of concentration were examined in mesenteric and cerebral arteries isolated from mature baboons. PGs E1, E2 and F2α at low concentrations (10−10 to 10−7 M) elicited relaxation in helically cut strips of cerebral arteries precontracted with phenylephrine. In contrast, the PGs did not cause relaxation in the mesentric artery. PGI2 (10−9 to 10−6 M) produced marked relaxation in both arteries. The EC25 for PGI2 in the mesenteric artery was significantly lower than that in the cerebral artery. During baseline conditions, cerebral arteries contracted in response to high concentrations (greater than 10−7 M) of PGs E1, E2 and F2α. In mesentric arteries, a large contraction was induced by PGs F2α and E2 but not by PGE1. Arachidonic acid (10−6 M) produced an aspirin-inhibitable relaxation in both arteries to a similar extent, so that the vasodilator PG(s) formed in the two different arterial walls appear to exert a similar relaxant action. Thus, the baboon mesenteric artery was more sensitive to PGI2 for the relaxant effect than was the cerebral artery, while PGs F2α, E1 and E2 caused only a contraction in the mesenteric artery but both relaxation and contraction in the cerebral artery. 相似文献
9.
The effect of six naturally occurring prostaglandins on isolated umbilical arteries and veins has been studied. All six prostaglandins had a constricting effect on the umbilical vessels. On the umbilical artery preparations the potencies in decreasing order were A2>B2>F2α>B1>E2>A1. Prostaglandin B2 was more potent than PGA2 on the umbilical vein. Polyphloretin phosphate (PPP) antagonised the constricting effect of all six prostaglandins without altering responses to 5-hydroxytryptamine. 相似文献
10.
Norman A. Nelson Robert W. Jackson Andrew T. Au 《Prostaglandins & other lipid mediators》1975,10(2):303-306
The synthesis of 2-decarboxy-2-(tetrazol-5-yl)prostaglandins of the E1, E2, F1α and F2α series is described together with their biological effects on gerbil colon smooth muscle and rat blood pressure. 相似文献
11.
Enrique Hong 《Prostaglandins & other lipid mediators》1974,8(3):213-220
Dose-response curves to prostaglandins (PG) E1, E2, F1α, F2α, A1 and A2 were carried out in the rat stomach fundus, rat colon, chick rectum and rabbit aortic strip superfused with Krebs solution containing adrenergic, cholinergic, serotonergic and histaminergic blockers, and arranged in a cascade fashion. In the stomach and rectum, the order of potency was PGE's > PGF's > PGA's. In the aorta and colon, PG2's were more active than their corresponding PG1's. By determining the colon/stomach and aorta/colon activity ratios, it was possible to define differential patterns of activity for PGE1, PGE2, PGF1α, PGF2α and PGA's. The present results indicate the importance of determining complete dose-response curves in the cascade for the characterization of PG-like activity. 相似文献
12.
Norman A. Nelson Robert W. Jackson Andrew T. Au 《Prostaglandins & other lipid mediators》1975,10(4):303-306
The synthesis of 2-decarboxy-2-(tetrazol-5-yl)prostaglandins of the E1, E2, F1α and F2α series is described together with their biological effects on gerbil colon smooth muscle and rat blood pressure. 相似文献
13.
Both sphincter and dilator muscle preparations of the cat iris contract to prostaglandins; F2α and E2 are the most potent and A1 and B1 the least. Ciliary muscle strips relax to PG's provided that the strips are precontracted. E1, E2 and often F2α are more potent relaxants than the remaining PG's. The effects of PG's are not altered by α or β blockade nor by atropine; however, propranolol blocks the PG induced relaxation of the ciliary muscle. The effects of PG's on the sphincter are antagonized by catecholamines; but the latter act synergistically in contracting the dilator and in relaxing the ciliary muscle. Indomethacin markedly potentiates the effects of PG's on all three muscle preparations. 相似文献
14.
Yoichi Chijimatsu Thinh Van Nguyen Sami I. Said 《Prostaglandins & other lipid mediators》1977,13(5):909-916
Prostaglandin endoperoxides are formed in the lung as intermediate compounds in the biosynthesis of prostaglandins and thromboxanes. The effects of different doses of two analogs of prostaglandin endoperoxide PGH2 were compared with those of PGF2α and PGE2 on superfused preparations of isolated trachea, bronchiole, peripheral lung, pulmonary artery and gastrointestinal smooth-muscle tissues. Endoperoxide analogs induced contraction of all smooth-muscle structures in the lung and airways. Compared to PGF2α, analog I was approximately 71 times as potent on guinea-pig trachea, 214 times as potent on guinea-pig lung, and 57 times as potent on guinea-pig polmunary artery. Analog II was moderately less potent on all tissues than analog I. On gastrointestinal smooth-muscle organs, the PGH2 analogs were generally closer in activity to PGF2α and PGE2, or even weaker. The findings show that PG endoperoxide vessels, and suggest that the naturally occurring compounds may participate in the mediation of bronchoconstriction and pulmonary vasoconstriction in disease states. 相似文献
15.
Recently we have found that chemotactic factors stimulate neutrophils in suspension to aggregate. Because of an obvious analogy to platelet aggregation, we examined the influence of three prostaglandins on this process. Prostaglandins E1, E2 and F2α alone did not cause aggregation of the neutrophils but were able to partially inhibit the aggregation response induced by the synthetic chemotactic tripeptide, formly-methionyl-leucyl-phenylalanine. The minimal inhibitory concentrations for prostaglandins E1, E2 and F2α were 10−7, 10−6 and 10−5M, respectively. These results are similar to those found for the prostaglandin-induced inhibition of platelet aggregation. It may be, therefore, that neutrophil aggregation, like platelet aggregation, is modulated by intracellular prostaglandins and other products of arachidonic acid metabolism. 相似文献
16.
T.G. Kennedy 《Prostaglandins & other lipid mediators》1976,12(6):1061-1071
Experiments were performed to determine if prostaglandins were able to reduce cervical tone in the rat. Cervical tone was assessed indirectly by measuring uterine luminal fluid accumulation in ovariectomized rats implanted subcutaneously with Silastic capsules containing crystalline estradiol-17β. When given subcutaneously in separate experiments, 16,16-dimethyl-prostaglandin E2, methyl ester, and 15(S)-15-methyl-prostaglandin F2α, analogous of prostaglandins E2 and F2α, respectively, caused the loss of uterine luminal fluid. Fluid accumulation in uterine horns ligated at the cervical end did not differ in control and treated rats, whereas in non-ligated horns the prostaglandin analogues reduced fluid accumulation, suggesting the cervix as their site of action. For both prostaglandin analogues, the effects on uterine luminal fluid accumulation were seen within 45 min of administration and were related to the dose administered. The effects of submaximal doses of the analogues were additive. These results suggest that prostaglandins are able to reduce cervical tone in the estrogen-treated rat. 相似文献
17.
P.L. Taylor 《Prostaglandins & other lipid mediators》1979,17(2):259-267
Evidence is presented for the existence of a group of 8-iso prostaglandins in human semen, comprising 8-iso PG E1*, 8-iso PG E2, 8-iso PG F1α, 8-iso PG F2α and the four corresponding 19-hydroxy prostaglandins. The E and F compounds have been positively identified by comparison of their mass spectra and chromatographic properties with those of authentic standards. Preliminary measurements of levels of these compounds in pooled semen are presented. 相似文献
18.
The relative bronchomotor activities of prostaglandins (PG) E1, E2, F2α, F2β and I2 and of three synthetic E prostaglandin analogues (TR4161, TR4367 and TR4752) were determined on a large number of isolated preparations of guinea-pig trachea and human bronchial muscle. Each prostaglandin was capable of eliciting both contraction and relaxation, the relative incidence of these responses partly depending on concentration. TR4161 was a virtually pure relaxant; TR4367 was virtually devoid of bronchomotor activity; and TR4752 was a potent relaxant, devoid of contractant activity. The results also provided distinct rank orders of approximate potency for contraction and relaxation. Tachyphylaxis to the relaxant activities of PGE1 and TR4752 confirmed the underlying contractant activity of the two natural E prostaglandins. Antagonism with a high dose of indomethacin of the contractant actions of PGE1, PGE2 and PGF2α confirmed the presence of relaxant activities in each.Inhaled aerosols of the same natural and synthetic prostaglandins were evaluated for irritant activity on the airways, using the cough response of the restrained conscious cat. All of them, except TR4161, elicited severe coughing. The rank order of potencies for irritancy differed from those for tracheobronchial contractant and relaxant activities.These findings suggest that the three responses studied arise from the activation of three distinct PG receptors in the airways. We propose the terms χ (contractant), ψ (relaxant) and ω (irritant) for these putative receptors for prostaglandins or possibly other prostanoids. 相似文献
19.
G. Dhondt A. Houvenaghel G. Peeters W. Jchle 《Prostaglandins & other lipid mediators》1977,13(6):1185-1199
The influence of prostaglandins (PG) F2α and E2 on milk ejection, mammary artery blood flow and arterial blood pressure was studied in lactating cows. Injections of both PG in the jugular vein or the carotid artery induced milk ejection after a relatively long latency period. The minimal effective dose amounted to 1 to 5 μg and to 100 to 300 μg for PGF2α and PGE2 respectively. In several cases with PGF2α and once with PGE2 milk ejection was accompanied with a simultaneous increase in blood flow through the mammary artery whereas arterial blood pressure remained unchanged. Both routes of administration showed the same response. It was suggested that the effect of the PG on the bovine myoepithelium is indirect, possibly secondary to a release of oxytocin from the neurohypophysis. 相似文献
20.
Prostaglandins A2, B1, E1, E2, F1α and F2α were added to cultures of human epidermal cells (keratinocytes) for 24 hours at 37°C, and the effects on 3H-thymidine uptake into DNA was measured. At 70 μg/ml all prostaglandins tested except PGF2α inhibited the uptake of 3H-thymidine greater than 50%. However, at 35 μg/ml, PGA2 and PGB1 were the only two prostaglandins to show significant inhibition, 96% and 51% respectively. At 17.5 μg/ml only PGA2 caused substantial inhibition, 68%. In order to determine if the PGA2 action was mediated by membrane receptors propranolol, phentolamine, metiamide and prostynoic acid were added in conjunction with PGA2. None of the above receptor antagonists were able to reduce the PGA2-induced inhibition of 3H-thymidine uptake. These results indicate that the pre-incubation of human keratinocytes with prostaglandins for 24 hours results in a decrease of 3H-thymidine incorporation in DNA. The precise mechanism of action is unknown at this time. 相似文献