Reduction in human neutrophil superoxide anion generation by n-3 polyunsaturated fatty acids: Role of cyclooxygenase products and endothelium-derived relaxing factor

1994 ◽  
Vol 76 (4) ◽  
pp. 317-322 ◽  
Author(s):  
L.Y. Chen ◽  
D.L. Lawson ◽  
J.L. Mehta
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Human Neutrophil ◽  
Superoxide Anion ◽  
Superoxide Anion Generation ◽  
Relaxing Factor ◽  
Endothelium Derived Relaxing Factor ◽  
Neutrophil Superoxide

Dietary omega 3 fatty acids and endothelium-dependent relaxations in porcine coronary arteries

1989 ◽  
Vol 256 (4) ◽  
pp. H968-H973 ◽  
Author(s):  
H. Shimokawa ◽  
P. M. Vanhoutte
Keyword(s):  
Fatty Acids ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Polyunsaturated Fatty Acids ◽  
Eicosapentaenoic Acid ◽  
Coronary Arteries ◽  
Treated Group ◽  
Omega 3 ◽  
Relaxing Factor ◽  
Endothelium Derived Relaxing Factor

Dietary supplementation with cod-liver oil significantly augments endothelium-dependent relaxations in porcine coronary arteries. The present study was designed to examine the effect of dietary administration of omega 3 polyunsaturated fatty acids (mainly eicosapentaenoic acid, the major component of fish oil) on endothelium-dependent relaxations in porcine coronary arteries. Male Yorkshire pigs were maintained 4 wk on a regular diet with or without supplementation with purified eicosapentaenoic acid (3.5 g/day) and docosahexaenoic acid (1.5 g/day). Endothelium-dependent relaxations were examined in vitro. In rings from the treated group, endothelium-dependent relaxations were augmented in response to bradykinin, serotonin, and ADP, but not to the calcium ionophore A23187. These augmentations were not altered by indomethacin but were significantly inhibited by methylene blue, an inhibitor of guanylate cyclase. In the treated group, endothelium-dependent relaxations to aggregating platelets also were significantly augmented; platelet-induced contractions of quiescent rings were inhibited more by the presence of the endothelium than in arteries from the control group. Bioassay experiments demonstrated that the release of endothelium-derived relaxing factor(s) by bradykinin and relaxations of the vascular smooth muscle to the factor(s) were greater in arteries from the treated group. These observations indicate that dietary omega 3 polyunsaturated fatty acids augment receptor-operated endothelium-dependent relaxations, partly due to the augmented release of endothelium-derived relaxing factor(s) and partly due to the augmented relaxation of the vascular smooth muscle to the factor(s).

Endothelium-dependent vasodilation by melittin: are lipoxygenase products involved?

1985 ◽  
Vol 249 (1) ◽  
pp. H14-H19 ◽  
Author(s):  
U. Forstermann ◽  
B. Neufang
Keyword(s):  
Fatty Acids ◽  
Arachidonic Acid ◽  
Polyunsaturated Fatty Acids ◽  
Rabbit Aorta ◽  
Membrane Phospholipids ◽  
Endothelium Derived Relaxing Factor ◽  
Potential Inhibitors ◽  
Endothelium Dependent Relaxation ◽  
Acid Compound

Vascular relaxation in response to acetylcholine and other vasodilator compounds has been shown to depend on intact endothelial cells. These dilator compounds obviously induce the formation of an unstable endothelium-derived relaxing factor or factors (EDRF) from the intima which relax the subjacent smooth muscle cells. The chemical identity of this factor (these factors) is still unclear. In the present study we demonstrate that endothelium-dependent relaxation of rabbit aorta was induced by melittin, a polypeptide toxin that activates phospholipase A2 to liberate polyunsaturated fatty acids (especially arachidonic acid) from membrane phospholipids. The relaxation induced by melittin had several properties similar to the acetylcholine relaxation. It was inhibited by potential inhibitors of phospholipase (mepacrine and p-bromophenacylbromide), by inhibitors of lipoxygenase (nordi-hydroguaiaretic acid, compound BW 755C, and 5,8,11,14-eicosatetraynoic acid) but not by the cyclooxygenase inhibitor indomethacin. An exogenous preparation of phospholipase C also induced endothelium-dependent relaxations. These findings support the hypothesis that oxidized metabolites of polyunsaturated fatty acids (e.g., arachidonic acid) may be involved directly (as mediators) or indirectly in the process of endothelium-dependent relaxation. On the other hand, exogenous arachidonic acid was a comparatively weak endothelium-dependent relaxant. However, this does not exclude an important role of endogenous arachidonic acid since the exogenous acid may not sufficiently reach its site of metabolism.

scholarly journals Emerging Role of Phospholipase-Derived Cleavage Products in Regulating Eosinophil Activity: Focus on Lysophospholipids, Polyunsaturated Fatty Acids and Eicosanoids

2021 ◽  
Vol 22 (9) ◽  
pp. 4356
Author(s):  
Eva Knuplez ◽  
Eva Maria Sturm ◽  
Gunther Marsche
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Critical Role ◽  
Allergic Inflammation ◽  
Lipid Mediators ◽  
Comprehensive Overview ◽  
Local Immunity ◽  
Effector Cells ◽  
Inflammatory Phenotype

Eosinophils are important effector cells involved in allergic inflammation. When stimulated, eosinophils release a variety of mediators initiating, propagating, and maintaining local inflammation. Both, the activity and concentration of secreted and cytosolic phospholipases (PLAs) are increased in allergic inflammation, promoting the cleavage of phospholipids and thus the production of reactive lipid mediators. Eosinophils express high levels of secreted phospholipase A2 compared to other leukocytes, indicating their direct involvement in the production of lipid mediators during allergic inflammation. On the other side, eosinophils have also been recognized as crucial mediators with regulatory and homeostatic roles in local immunity and repair. Thus, targeting the complex network of lipid mediators offer a unique opportunity to target the over-activation and ‘pro-inflammatory’ phenotype of eosinophils without compromising the survival and functions of tissue-resident and homeostatic eosinophils. Here we provide a comprehensive overview of the critical role of phospholipase-derived lipid mediators in modulating eosinophil activity in health and disease. We focus on lysophospholipids, polyunsaturated fatty acids, and eicosanoids with exciting new perspectives for future drug development.

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