Effects of lipoxin A4 on chemotaxis and degranulation of human eosinophils stimulated by platelet-activating factor and N-formyl-L-methionyl-L-leucyl-L-phenylalanine |
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| Authors: | O Soyombo B W Spur T H Lee |
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| Institution: | Department of Allergy and Allied Respiratory Disorders, UMDS, Guy's Hospital, London, UK |
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| Abstract: | Lipoxins are trihydroxytetraene metabolites derived through a double lipoxygenation of arachidonic acid. Lipoxin A4 (LXA4) was prepared by total chemical synthesis, and its capacity to modulate eosinophil migration has been evaluated. LXA4 is a weak and partial chemotactic agent; at 10−6 M, it achieved about 20% of the response of 10−6 M platelet-activating factor (PAF). Preincubation of eosinophils with increasing doses of LXA4 (10−10−10−5 M) resulted in a concentration-dependent inhibition of cell migration induced by 10-6 M formyl-methionyl-leucyl-phenylalanine (FMLP) and 10-6 M PAF. The concentration of LXA4 which produced 50% inhibition (IC50) of eosinophil migration was approximately 10-6 M. LXA4 (10-10-10-6 M) did not elicit ECP release or modulate ECP release induced by 10-6 M FMLP. LXA4 may have antiallergic properties in preventing eosinophilic migration. |
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| Keywords: | allergy asthma chemotaxis eosinophil leukotriene lipoxin |
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