Leukotrienes
Mostrando 25-36 de 171 artigos, teses e dissertações.
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25. Agentes antiasmáticos modernos: antagonistas de receptores de leucotrienos cisteínicos
In the early 1990s numerous clinical trials with antileukotriene drugs confirmed the hypothesis that cysteinyl leukotrienes are important bronchoconstrictor agents in asthma. Newly released"antiasthmatic medications include antileukotriene agents which function either by blocking the interaction of leukotrienes with receptors or by inhibiting leukotriene syn
Química Nova. Publicado em: 2002-09
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26. Effect of fatty acids on leukocyte function
Fatty acids have various effects on immune and inflammatory responses, acting as intracellular and intercellular mediators. Polyunsaturated fatty acids (PUFAs) of the omega-3 family have overall suppressive effects, inhibiting lymphocyte proliferation, antibody and cytokine production, adhesion molecule expression, natural killer cell activity and triggering
Brazilian Journal of Medical and Biological Research. Publicado em: 2000-11
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27. Mediação química da hiperagesia induzida pelos venenos de serpentes Bothrops jararaca e Bothrops asper e por uma miotoxina com atividade de fosfolipase A2 isolada do veneno de Bothrops asper / Chemical mediation of hyperalgesia induced by Bothrops jararaca and Bothrops asper snake venoms and by a phospholipase A2 miotoxin isolated from Bothrops asper venom.
Bothrops venoms cause pronounced local tissue-damage characterized by hemorrhage, myonecrosis, edema and pain. Venom-induced pain has been poorly investigated, despite its clinical relevance. Furthermore, the ability of antivenom to neutralize hyperalgesia induced by these venoms is not known. In the present study the hyperalgesia and edema induced by Bothro
Publicado em: 2000
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28. Leukotrienes promote plasma leakage and leukocyte adhesion in postcapillary venules: in vivo effects with relevance to the acute inflammatory response.
Leukotrienes B4, C4, and D4, members of a recently discovered family of substances biosynthesized from arachidonic acid, were found to have potent microvascular actions in the hamster cheek pouch. When applied topically to the vascular network, leukotrienes C4 and D4 caused an intense constriction of arterioles, being similar to angiotensin in potency in thi
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29. Leukotrienes as mediators in ischemia-reperfusion injury in a microcirculation model in the hamster.
Leukotriene (LT)B4 promotes leukocyte chemotaxis and adhesion to the endothelium of postcapillary venules. The cysteinyl leukotrienes, LTC4, LTD4, and LTE4, elicit macromolecular leakage from this vessel segment. Both leukocyte adhesion to the endothelium and macromolecular leakage from postcapillary venules hallmark the microcirculatory failure after ischem
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30. Allergen challenge of lung tissue from asthmatics elicits bronchial contraction that correlates with the release of leukotrienes C4, D4, and E4.
The leukotrienes C4, D4, and E4, previously referred to as slow reacting substance of anaphylaxis, elicited long-lasting contractions of bronchi isolated from two birch pollen-sensitive asthmatics. The leukotrienes were 1,000 times more potent on a molar basis than was histamine or prostaglandin F2 alpha. Moreover, allergen released leukotrienes C4, D4, and
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31. Transcellular biosynthesis contributes to the production of leukotrienes during inflammatory responses in vivo
Leukotrienes are lipid mediators that evoke primarily proinflammatory responses by activating receptors present on virtually all cells. The production of leukotrienes is tightly regulated, and expression of 5-lipoxygenase, the enzyme required for the first step in leukotriene synthesis, is generally restricted to leukocytes. Arachidonic acid released from th
American Society for Clinical Investigation.
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32. Impaired degradation of leukotrienes in patients with peroxisome deficiency disorders.
The degradation of leukotrienes by beta-oxidation from the omega-end proceeds in peroxisomes (Jedlitschky et al. J. Biol. Chem. 1991. 266:24763-24772). Peroxisomal degradation of leukotrienes was studied in humans by analyses of endogenous leukotrienes in urines from eight patients with biochemically established peroxisome deficiency disorder and eight age-
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33. 5-Lipoxygenase Reaction Products Modulate Alveolar Macrophage Phagocytosis of Klebsiella pneumoniae
The leukotrienes are potent lipid mediators of inflammation formed by the 5-lipoxygenase-catalyzed oxidation of arachidonic acid. Although the effects of leukotrienes on neutrophil chemotaxis and activation have been established, their role in modulating innate host defense mechanisms is poorly understood. In a previous study (M. Bailie, T. Standiford, L. La
American Society for Microbiology.
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34. Leukotriene E4-induced airway hyperresponsiveness of guinea pig tracheal smooth muscle to histamine and evidence for three separate sulfidopeptide leukotriene receptors.
Bronchial hyperresponsiveness to contractile agonists and nonspecific irritants is a characteristic feature of bronchial asthma. The mechanisms causing this hyperirritability are unknown. The existence of separate receptors for leukotrienes C4 and D4 (LTC4 and LTD4) has been demonstrated previously by physiologic and radioligand binding studies. The rank ord
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35. Leukotrienes in the rat central nervous system.
Leukotrienes C4, D4, and E4 were isolated after incubation of rat brain tissue in vitro with the ionophore A23187 and arachidonic acid. Identification of the compounds was carried out using high-performance liquid chromatography, radioimmunoassay, and bioassay. Average production of leukotrienes C4, D4, and E4 during 10 min of incubation was estimated to 25,
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36. Contractile activities of structural analogs of leukotrienes C and D: necessity of a hydrophobic region.
Sixteen structural analogs of leukotrienes C and D were tested for their contractile activities on guinea pig pulmonary parenchymal strip and ileum. The analogs differed from the native structures in the position of either the thioether-linked peptide side chain or the hydroxyl group (or both) or in the number and positions of ethylenic bonds. Analogs in whi