Activation of the lipoxygenase pathway in the methionine enkephalin induced respiratory burst in human polymorphonuclear leukocytes.
In comparative studies of f-met-Leu-Phe (FMLP) and methionine enkephalin (ME) induced polymorphonuclear leukocyte (PMNL) stimulation the following results were obtained: (i) both FMLP and ME increased the intracellular killing (IK) capability of human PMNLs probably through NADPH oxidase activation, (ii) the ME-induced respiratory burst (RB) differed from the chemotactic peptide FMLP-triggered superoxide generation because the former was not accompanied by the activation of the glutathione system and the duration of the superoxide production was prolonged. The reaction was dependent on lipoxygenation, was potentiated by indomethacin (IM) and was inhibited by nordihidro-guairetic acid (NDGA), (iii) both 14C-arachidonic acid (14C-AA) release and leukotriene B4 (LTB4) synthesis of ME-treated PMNLs were elevated as compared to those of FMLP triggered cells. Our results suggest that lipoxygenation and even an increased LTB4 synthesis are involved in the ME-induced RB of leukocytes.
Nagy
J T
JT
First Department of Medicine, University Medical School, Debrecen, Hungary.
Foris
G
G
Fulop
T
T
Paragh
G
G
Plotnikoff
N P
NP
D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000097:blood; D004744:Enkephalin, Methionine / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D005978:Glutathione / Q000097:blood; D005979:Glutathione Peroxidase / Q000097:blood; D005980:Glutathione Reductase / Q000097:blood; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D007975:Leukotriene B4 / Q000097:blood; D008084:Lipoxygenase / Q000097:blood*; D009637:Masoprocol / Q000494:pharmacology; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009247:NADH, NADPH Oxidoreductases / Q000097:blood; D019255:NADPH Oxidases; D009270:Naloxone / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects*; D013481:Superoxides / Q000097:blood
D001095:Arachidonic Acids; D013481:Superoxides; D007975:Leukotriene B4; D016718:Arachidonic Acid; D009270:Naloxone; D004744:Enkephalin, Methionine; D009240:N-Formylmethionine Leucyl-Phenylalanine; D009637:Masoprocol; D005979:Glutathione Peroxidase; D008084:Lipoxygenase; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; D005980:Glutathione Reductase; D005978:Glutathione; D007213:Indomethacin