Low doses of urban air particles from Buenos Aires promote oxidative stress and apoptosis in mice lungs.
Air pollution consists of a wide range of gaseous and particulate pollutants. Exposure to particulate matter (PM) can cause oxidative stress within the lung, which in turn can negatively impact health. The mechanisms by which PM causes oxidative stress include the release of trace metals or organic components from the particle. Previously, we have characterized urban air particles from downtown Buenos Aires (UAP-BA) and, by using in vivo animal studies, found that they are able to generate lung inflammation.


OBJECTIVE
We studied lung responses to low doses of UAP-BA (15 µg), with special emphasis on oxidative balance.


METHODS
We assessed cell viability, total cell number (TCN) and cell differential (CD) on bronchoalveolar lavages (BAL), oxidative metabolism in lung homogenates by tertbutylhydroperoxide-initiated chemiluminescence (CL), thiobarbituric reactive substances (TBARS), total reactive antioxidant potential (TRAP), reduced glutathione (GSH), and apoptosis in lung sections.


RESULTS
We found that low UAP-BA exposure increases TCN, modifies CD, and decreases cell viability in the BAL. In lung homogenates, TBARS and CL rose while TRAP and GSH showed no alteration when compared to controls. Occurrence of apoptosis evaluated by TUNEL assay was markedly augmented in UAP-BA exposed animals.


CONCLUSIONS
Our data further implicate oxidative stress as a possible inducer of apoptosis in lungs from animals exposed to low concentrations of this urban environmental contaminant.
School of Science and Technology, National University of San Martín, San Martín, Buenos Aires, Argentina.
Susana
S
Martin
Eugenio
E
Fernandez-Alanis
Veronica
V
Delfosse
Pablo
P
Evelson
Juan S
JS
Yakisich
Paulo H
PH
Saldiva
Deborah R
DR
Tasat
D000393:Air Pollutants / Q000633:toxicity*; D000397:Air Pollution; D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis; D001118:Argentina; D001992:Bronchoalveolar Lavage Fluid; D002470:Cell Survival; D002947:Cities; D005978:Glutathione / Q000032:analysis; D008168:Lung / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018384:Oxidative Stress; D010316:Particle Size; D052638:Particulate Matter / Q000633:toxicity*; D011014:Pneumonia / Q000139:chemically induced*; D017392:Thiobarbituric Acid Reactive Substances
D000393:Air Pollutants; D000975:Antioxidants; D052638:Particulate Matter; D017392:Thiobarbituric Acid Reactive Substances; D005978:Glutathione