Production of 15-hydroxyeicosatetraenoic acid by purified human eosinophils and neutrophils.
In the presence of high concentrations of exogenous arachidonic acid (greater than or equal to 10 microM), eosinophils produced 15-hydroxyeicosatetraenoic acid (15-HETE) in the absence of stimuli. The calcium ionophore A23187, as well as the chemotaxins used in this study--complement split product C5a, platelet-activating factor (PAF), and N-formyl-methionyl-leucyl-phenylalanine (FMLP)--failed to increase 15-HETE production, indicating that eosinophil 15-lipoxygenase is already active. Production of 15-HETE from eosinophils increased with increasing concentrations of arachidonic acid, exogenously added. Maximal 15-HETE production was observed to be 1111 +/- 380 ng per 10(6) eosinophils at the concentration of 100 microM of arachidonic acid. With low concentrations of exogenous arachidonic acid (below 2 microM), eosinophils were considered to incorporate exogenous arachidonic acid into their cell membrane, and did not produce 15-HETE. In contrast, 15-HETE formation in highly purified neutrophils (eosinophils less than 1%) was negligible compared with that in eosinophils (300-fold less), suggesting that 15-HETE-forming activity in granulocytes is derived from the eosinophil 15-lipoxygenase pathway and that neutrophils may lack 15-lipoxygenase activity.
Morita
E
E
Department of Dermatology, Hiroshima University School of Medicine, Japan.
Schröder
J M
JM
Christophers
E
E
D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism; D000001:Calcimycin / Q000494:pharmacology; D002469:Cell Separation; D015936:Complement C5a / Q000494:pharmacology; D004804:Eosinophils / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000096:biosynthesis*; D066298:In Vitro Techniques; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010972:Platelet Activating Factor / Q000494:pharmacology
D001095:Arachidonic Acids; D006893:Hydroxyeicosatetraenoic Acids; D010972:Platelet Activating Factor; D016718:Arachidonic Acid; D000001:Calcimycin; D009240:N-Formylmethionine Leucyl-Phenylalanine; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; D015936:Complement C5a