title: Comparison of 5- and 15-lipoxygenase activities in blood and alveolar leukocyte preparations from normal subjects and patients with eosinophilia.
abstract: The arachidonic acid lipoxygenase metabolites of polymorphonuclear leukocyte (PMNL) preparations obtained from 31 subjects with eosinophilia (eosinophil content of PMNL preparations: 27.0%, 4-73, median with range) and 29 normal donors (4.5%, 0-15) were analyzed by reversed phase high performance liquid chromatography. More leukotriene (LT) C4 and 15-hydroxyeicosatetraenoic acid (HETE) (p less than 0.001) and less LTB4 (p less than 0.005) were found in eosinophil-rich preparations in comparison to controls on incubations with ionophore and arachidonic acid. In incubations with arachidonic acid alone, only small amounts of 5-lipoxygenase metabolites were produced by both groups, but the PMNL preparations from patients with eosinophilia showed higher capacity to release LTC4 and 15-HETE (p less than 0.005). In the eosinophil-rich preparations, the percentage of eosinophils correlated positively with the production of LTC4 and negatively with LTB4 (p less than 0.05, incubations with ionophore +/- arachidonic acid), and positively with 15-HETE (p less than 0.01, incubations with arachidonic acid +/- ionophore). Moreover the eosinophil-rich preparations produced more LTC4 per eosinophil in incubations with arachidonic acid alone (p less than 0.001) than normal PMNL preparations. The predominant release of LTC4 and 15-HETE by eosinophils was further confirmed by the analysis of bronchoalveolar lavage cells. Lavage cells containing eosinophils released LTC4 and 15-HETE while normal bronchoalveolar lavages, which were poor in eosinophils, did not produce detectable amount of LTC4 and 15-HETE. These results show that eosinophils release preferentially LTC4 and 15-HETE in contrast to LTB4 for the neutrophils.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001093:Arachidonate 15-Lipoxygenase / Q000097:blood / Q000502:physiology*; D001094:Arachidonate 5-Lipoxygenase / Q000097:blood / Q000502:physiology*; D001091:Arachidonate Lipoxygenases / Q000502:physiology*; D001095:Arachidonic Acids / Q000378:metabolism; D002648:Child; D002851:Chromatography, High Pressure Liquid; D004802:Eosinophilia / Q000097:blood*; D004804:Eosinophils / Q000201:enzymology / Q000378:metabolism; D005260:Female; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000378:metabolism; D007962:Leukocytes / Q000201:enzymology*; D007975:Leukotriene B4 / Q000378:metabolism; D008264:Macrophages / Q000201:enzymology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000201:enzymology / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000166:cytology*; D012016:Reference Values; D013189:SRS-A / Q000378:metabolism
chemical_list: D001095:Arachidonic Acids; D006893:Hydroxyeicosatetraenoic Acids; D013189:SRS-A; D007975:Leukotriene B4; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; D001091:Arachidonate Lipoxygenases; D001093:Arachidonate 15-Lipoxygenase; D001094:Arachidonate 5-Lipoxygenase