leukotriene-a4 has been researched along with Nasal-Polyps* in 3 studies
3 other study(ies) available for leukotriene-a4 and Nasal-Polyps
| Article | Year |
|---|---|
Conversion of leukotriene A4 to lipoxins by human nasal polyps and bronchial tissue.
Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Arachidonate 15-Lipoxygenase; Bronchi; Humans; Hydroxyeicosatetraenoic Acids; Leukotriene A4; Leukotrienes; Lipoxins; Nasal Polyps; Neutrophils | 1991 |
Lipoxin formation in human nasal polyps and bronchial tissue.
Chopped human nasal polyps and bronchial tissue produced lipoxin A4 and isomers of lipoxins A4 and B4, but not lipoxin B4, after incubation with exogenous leukotriene A4. In addition, these tissues transformed arachidonic acid to 15-hydroxyeicosatetraenoic acid. The capacity per gram of tissue to produce lipoxins and 15-hydroxyeicosatetraenoic acid was 3-5-times higher in the nasal polyps. Neither tissue produced detectable levels of lipoxins or leukotrienes after incubation with ionophore A23187 and arachidonic acid. Co-incubation of nasal polyps and polymorphonuclear granulocytes with ionophore A23187 led to the formation of lipoxins, including lipoxins A4 and B4. The results indicate the involvement of an epithelial 15-lipoxygenase in lipoxin formation in human airways. Topics: Arachidonate 15-Lipoxygenase; Arachidonic Acid; Arachidonic Acids; Bronchi; Calcimycin; Humans; Hydroxyeicosatetraenoic Acids; Leukotriene A4; Leukotrienes; Lipoxins; Nasal Polyps; Neutrophils | 1990 |
Conversion of leukotrienes A4 to C4 in cell-free systems.
A procedure for assaying leukotriene C4 synthase activity in cell-free extracts has been presented. Leukotriene A4 methyl ester was as active a substrate as leukotriene A4 (Na salt) for the synthesis. The methyl ester is the substrate of choice, because (1) it is more stable than the sodium salt, (2) it is not a substrate of epoxide hydrolase for leukotriene B4 synthesis, and (3) it gives a lower blank than an equimolar concentration of leukotriene A4. The enzyme activity in rat liver, guinea pig and human lungs, and human nasal polyp was chiefly membrane-bound, although the cytosol contained some activity. Topics: Animals; Arachidonic Acids; Cell-Free System; Chromatography, High Pressure Liquid; Glutathione Transferase; Guinea Pigs; Humans; Leukotriene A4; Liver; Lung; Male; Nasal Polyps; Rats; Rats, Inbred Strains; SRS-A | 1986 |