Inflammatory and genotoxic responses during 30-day welding-fume exposure period.
Welder's pneumoconiosis has generally been determined to be benign and unassociated with respiratory symptoms based on the absence of pulmonary-function abnormalities in welders with marked radiographic abnormalities. In previous studies, the current authors suggested a three-phase lung fibrosis process to study the pathological process of lung fibrosis and found that the critical point for recovery was after 30 days of welding-fume exposure at a high dose, at which point early and delicate fibrosis was observed in the perivascular and peribronchiolar regions. Accordingly, the current study investigated the inflammatory and genotoxic responses during a 30-day period of welding-fume exposure to elucidate the process of fibrosis. As such, rats were exposed to manual metal arc-stainless steel (MMA-SS) welding fumes at concentrations of 65.6 +/- 2.9 (low dose) and 116.8 +/- 3.9 mg/m3 (high dose) total suspended particulate for 2 h per day in an inhalation chamber for 30 days. Animals were sacrificed after the initial 2 h exposure, and after 15 and 30 days of exposure. The rats exposed to the welding fumes exhibited a statistically significant (P < 0.05) decrease in body weight when compared to the control during the 30-day exposure period, yet an elevated cellular differential count and higher levels of albumin, LDH, and beta-NAG, but not elevated TNF-alpha, and IL-1beta in the acellular bronchoalveolar lavage fluid. In addition, the DNA damage resulting from 30 days of welding-fume exposure was confirmed by a comet assay and the inmmunohistochemistry for 8-hydroxydeoxyguanine (8-OH-dG). Consequently, the elevated inflammatory and genotoxic indicators confirmed the lung injury and inflammation caused by the MMA-SS welding-fume exposure.
Center for Occupational Toxicology, Occupational Safety and Health Research Institute, Korea Occupational Safety and Health Agency, 104-8 Munji-dong, Yuseong-gu, Daejeon 305-380, Republic of Korea. u1670916@chollian.net
Il Je
IJ
Yu
Kyung Seuk
KS
Song
Seung Hee
SH
Maeng
Soo Jin
SJ
Kim
Jae Hyuck
JH
Sung
Jeong Hee
JH
Han
Yong Hyun
YH
Chung
Myung Haing
MH
Cho
Kyu Hyuck
KH
Chung
Kuy Tae
KT
Han
Jin Sook
JS
Hyun
Kwang Jong
KJ
Kim
D000080242:8-Hydroxy-2'-Deoxyguanosine / Q000031:analogs & derivatives; D000118:Acetylglucosaminidase / Q000032:analysis; D000395:Air Pollutants, Occupational / Q000633:toxicity*; D000418:Albumins / Q000032:analysis; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D020552:Comet Assay; D004247:DNA / Q000187:drug effects; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D006147:Guanine / Q000031:analogs & derivatives* / Q000378:metabolism; D019570:Inhalation Exposure; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D007958:Leukocyte Count; D008168:Lung / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D016676:Macrophages, Alveolar / Q000187:drug effects / Q000473:pathology; D008297:Male; D011658:Pulmonary Fibrosis / Q000139:chemically induced* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013047:Specific Pathogen-Free Organisms; D013193:Stainless Steel; D014896:Welding
D000395:Air Pollutants, Occupational; D000418:Albumins; D013193:Stainless Steel; D006147:Guanine; C078307:8-oxo-7,8-dihydrodeoxyguanine; D000080242:8-Hydroxy-2'-Deoxyguanosine; D004247:DNA; D007770:L-Lactate Dehydrogenase; D000118:Acetylglucosaminidase