title: Oxidative injury in the lungs of neonatal rats following short-term exposure to ultrafine iron and soot particles.
abstract: Greater risk of adverse effects from particulate matter (PM) has been noted in susceptible subpopulations, such as children. However, the physicochemical components responsible for these biological effects are not understood. As critical constituents of PM, transition metals were postulated to be involved in a number of pathological processes of the respiratory system through free radical-medicated damage. The purpose of this study was to examine whether oxidative injury in the lungs of neonatal rats could be induced by repeated short-term exposure to iron (Fe) and soot particles. Sprague Dawley rats 10 d of age were exposed by inhalation to two different concentrations of ultrafine iron particles (30 or 100 microg/m(3)) in combination with soot particles adjusted to maintain a total particle concentration of 250 microg/m(3). Exposure at 10 d and again at 23 d of age was for 6 h/d for 3 d. Oxidative stress was observed at both Fe concentrations in the form of significant elevations in glutathione disulfide (GSSG) and GSSG/glutathione (GSH) ratio and a reduction in ferric/reducing antioxidant power in bronchoalveolar lavage. A significant decrease in cell viability associated with significant increases in lactate dehydrogenase (LDH) activity, interleukin-1-beta (IL-1beta), and ferritin expression was noted following exposure to particles containing the highest Fe concentration. Iron from these particles was shown to be bioavailable in an in vitro assay using the physiologically relevant chelator, citrate. Data indicate that combined Fe and soot particle exposure induces oxidative injury, cytotoxicity and pro-inflammatory responses in the lungs of neonatal rats.
authors.affiliation: Center for Health and the Environment, University of California, Davis, California 95616, USA.
authors.forename: Cai-Yun
authors.initials: CY
authors.lastname: Zhong
authors.forename: Ya-Mei
authors.initials: YM
authors.lastname: Zhou
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Smith
authors.forename: Ian M
authors.initials: IM
authors.lastname: Kennedy
authors.forename: Chao-Yin
authors.initials: CY
authors.lastname: Chen
authors.forename: Ann E
authors.initials: AE
authors.lastname: Aust
authors.forename: Kent E
authors.initials: KE
authors.lastname: Pinkerton
mesh_terms: D000280:Administration, Inhalation; D000336:Aerosols; D000393:Air Pollutants / Q000633:toxicity*; D000818:Animals; D000831:Animals, Newborn; D000975:Antioxidants / Q000032:analysis; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D002470:Cell Survival / Q000187:drug effects; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D005290:Ferric Compounds / Q000633:toxicity*; D005293:Ferritins / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D008168:Lung / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects*; D010316:Particle Size; D052638:Particulate Matter / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D053260:Soot / Q000633:toxicity*
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D000975:Antioxidants; D016207:Cytokines; D005290:Ferric Compounds; D052638:Particulate Matter; D053260:Soot; C000499:ferric oxide; D005293:Ferritins; D005978:Glutathione