Products of 5-lipoxygenase and myeloperoxidase activities are increased in young male cigarette smokers.
The significance of 5-lipoxygenase and myeloperoxidase activities has not been extensively studied among young male smokers. Leukotriene B(4), 20-hydroxy-leukotriene B(4), 20-carboxy-leukotriene B(4) and 3-chlorotyrosine were measured in plasma and urinary samples of young male smokers at 8 hours following cigarette abstinence and an hour after cigarette smoking. Leukotriene B(4) and 3-chlorotyrosine were determined in neutrophils isolated from these individuals. The levels of these markers were compared with those of age-matched controls. In vitro studies were performed to evaluate the production of leukotriene B(4) and 3-chlorotyrosine from human neutrophils following exposure to nicotine and cotinine. Thirty male smokers (mean age, 27.4 years) and 28 male non-smokers (mean age, 28.7 years) were studied. Plasma levels of leukotriene B(4), 20-carboxy-leukotriene B(4) and 3-chlorotyrosine were higher in smokers than in non-smokers; leukotriene B(4) and 20-carboxy-leukotriene B(4) levels increased further an hour after cigarette smoking. Peripheral neutrophils isolated from smokers showed greater expressions of myeloperoxidase and 5-lipoxygenase activities compared with non-smokers, while plasma leukotriene B(4) and 3-chlorotyrosine were correlated significantly with high-sensitivity C-reactive protein and plasma nicotine concentrations. Exposure of human neutrophils to nicotine and cotinine resulted in a higher production of leukotriene B(4) and 3-chlorotyrosine. To conclude, leukotriene B(4) and 3-chlorotyrosine levels are increased in young male cigarette smokers. These results suggest that cigarette smoking aggravates neutrophil-mediated inflammation by modulating the activities of myeloperoxidase and 5-lipoxygenase pathways.
Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Wai Mun
WM
Loke
Karen Mary-Jane
KM
Lam
Wan Ling
WL
Chong
Soh Eng
SE
Chew
Amy Ml
AM
Quek
Erle Ch
ECh
Lim
Raymond Cs
RC
Seet
D000328:Adult; D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism*; D016022:Case-Control Studies; D006801:Humans; D007975:Leukotriene B4 / Q000378:metabolism; D008297:Male; D009504:Neutrophils / Q000201:enzymology / Q000473:pathology; D009195:Peroxidase / Q000378:metabolism*; D012907:Smoking / Q000097:blood / Q000378:metabolism* / Q000652:urine; D055815:Young Adult
D007975:Leukotriene B4; D009195:Peroxidase; D001094:Arachidonate 5-Lipoxygenase