The Toxicologist - Society of Toxicology

therefore more accurate and reproducible instillation is possible. And this overcomes
some problems occurred in the adopting process of previous model to mice.
To validate this, instillation of Evance Blue dye and induction of lung fibrosis with
Bleomycin have been performed. The instilled dye dispersed well on the whole
lungs and the variation of fibrosis prognosis was low. Based on the results of these
examinations, we concluded that the device could be used for rapid, reproducible
and successful ITI of a test compound into the lungs of mice.
591 IN VITRO AND IN VIVO ANALYSIS OF SIZE-
FRACTIONATED PM FROM DIFFERENT U.S. CITIES.
C. A. Hickey, L. Horton, K. Galdanes, M. Lippmann and T. Gordon.
Environmental Medicine, New York University School of Medicine, Tuxedo, NY.
A strong association between ambient PM and adverse cardiopulmonary health effects
has been consistently reported. As PM toxicity has shown differences depending
on particle size, season, and location, it has become clear that mass concentration
alone may not be the best indicator of PM-induced health effects. We
hypothesized that the differences in the PM composition account for these varied
effects. A high volume cascade impactor was used to collect over 350 size-fractioned
PM samples from five U.S. cities in 2007-08. In vitro analysis was conducted using
a human pulmonary microvascular endothelial cell line (HPMEC-ST1.6R) and a
human bronchial epithelial cell line (BEAS-2B). Results show size and seasonal effects
on reactive oxygen species (ROS) formation (as measured by oxidation of a
fluorescent dye) when data is separated by city. For example, winter coarse samples
from Anaheim, CA elicited a greater production of ROS than the corresponding
summer samples, while the opposite was true for the fine and ultrafine samples.
Interestingly, both cell types did not respond similarly in all instances suggesting
they have different sensitivities and response pathways. Following 6 and 24 h treatments
with PM, mRNA expression levels for markers of ROS and cellular inflammation
were measured by real-time RT-PCR. Results show differences in expression
depending on size, city and duration of exposure. The most notable expression
changes were observed for HO-1 and IL-8. Additionally, a subset of samples was
analyzed in a murine model using oropharyngeal aspiration of PM. PMN levels
measured in BAL did not correlate with in vitro ROS production suggesting the
ROS production may not be the best indicator of PM toxicity in vivo. Our results
support the hypothesis that the elemental composition of PM drives PM-induced
health effects as indicated by differences in response depending in size, city and location.
Future studies aim to correlate these findings with individual elemental data
and source apportionment.
592 TOBACCO SMOKE MODULATES THE PULMONARY
AND CNS EFFECTS OF OZONE INHALATION IN RATS.
V. Bhoopalan 1 , M. M. Shah 1, 3 , D. M. Thomas 1, 3 , S. Han 2 and D. K. Bhalla 1 .
1 Pharmaceutical Sciences, Wayne State University, Detroit, MI, 2 Animal and Food
Sciences, University of Kentucky, Lexington, KY and 3 R&D Service, John D. Dingell
VAMC, Detroit, MI.
Ozone (O3), an oxidant air pollutant, and tobacco smoke (TS) are known risk factors
in the development of lung injury and chronic disease. While the independent
toxicity of these pollutants has been widely studied, their interactive effects are
poorly defined. This study was performed to determine if sequential exposures of
rats to O3 and TS will influence the toxic responses of O3 in the lungs and brain.
Adult Sprague Dawley (SD) male rats were exposed for a single 3 hr period to O3,
TS or O3 plus TS in sequence. In all, 3 exposure groups were evaluated: 1) Air
(control), 2) O3, 3) O3 followed by TS (O3/TS). Bronchoalveolar lavage (BAL)
was performed, and BAL cells and fluid were analyzed. Data revealed a significant
increase in polymorphonuclear leukocytes (PMN) and total BAL protein in the O3
group compared to the control, reflecting the inflammatory and cytotoxic effects of
O3. However, a subsequent exposure to TS attenuated PMN infiltration into the
air spaces for recovery in the BAL of the O3/TS group. A similar reduction was also
observed for BAL protein in the O3/TS group, but it was not significant. Since O3
also induces deleterious effects in the brain, including the nigrostriatal pathway and
because the dopaminergic cells of this region are thought to be hypersensitive to oxidative
stress, we measured striatal dopamine levels in the O3 and O3/TS groups by
HPLC with electrochemical detection. Data revealed O3 reduced striatal dopamine
content, while the subsequent TS exposure afforded a nonsignificant protection.
Overall, the results show that the toxicity of O3 in the lung and brain are modulated
by exposure to TS. The results are contrary to the synergistic toxicity predicted
for TS and O3, and are comparable to the attenuated responses following sequential
exposures to carbon nanotubes and O3 reported in our previous studies.
Supported in part by funding from OVPR-WSU, NIDA and VA.
593 CYTOPROTECTIVE GENE EXPRESSION BY
ACTIVATION OF NRF2 TRANSCRIPTION FACTOR IN
LUNG OF RATS EXPOSED TO FINE AND ULTRAFINE
AMBIENT PARTICULATE MATTER IN MEXICO CITY.
A. Valdés-Arzate1 , M. Uribe-Ramirez1 , O. G. Aztatzi-Aguilar1 , M. Tinoco-
Mendez2 , C. Gómez-Ruiz2 , I. Gracia-Mora3 , M. T. Kleinman4 and A. De
Vizcaya-Ruiz1 . 1Department of Toxicology, Cinvestav, Mexico City, Mexico, 2Unidad de Experimentación Animal, Facultad de Quimica, UNAM, Mexico City, Mexico,
3Departamento de Quimica Inorganica y Nuclear, Facultad de Quimica, UNAM,
Mexico City, Mexico and 4Division of Occupational and Environmental Medicine,
Department of Medicine, University of California Irvine, Irvine, CA.
Exposure to particulate matter (PM) has been associated with adverse health effects
possibly initiated by oxidative stress within affected cells. The Nrf2 transcription
factor, a master regulator of basal and inducible expression of detoxification and antioxidant
enzymes such as superoxide dismutase (SOD-2), glutathione-S-transferases
(GST) and heme oxygenase-1 (HO-1), can be activated in response to this
type of stimuli. The aim of this study was to evaluate the cytoprotective response
induction of Nrf2 from the exposure to PM in Mexico City. Sprague-Dawley male
rats were randomly assigned into 4 groups (n=6) and exposed to coarse (C), fine (F)
ultrafine (UF) or filtered air (FA) using a particle concentrator for 3 days and 8
weeks. Activation of Nfr2 in the lung was assessed by electrophoresis mobility shift
assay (EMSA) and immunohistochemistry localization, and mRNA contents of
HO-1, SOD-2 and GST were determined using RT-PCR. Our results show that F
and UF PM increases Nrf2 nuclear translocation and ARE-binding in comparison
to FA and C exposure groups, in the lung, leading to increased expression of SOD-
2, GST and HO-1 genes at 3 days and 8 weeks. Thus, the acute (3 day) and subchronic
(8 week) exposure to F and UF particles induce a significant coordinated
induction of cytoprotective genes (HO-1, SOD-2 and GST) through activation of
Nrf2 confering an adaptive survival response against toxicity caused by ambient F
and UF deposited in the lung suggesting that Nrf2-activation is a key regulator of
antioxidant defense responses that protects against pulmonary oxidative damage
caused by PM. (Project financed by: CONACyT #57752 and UCLA-Fogarty
Program).
594 DETERMINATION OF HAZARD ASSOCIATED WITH
AMINE AND AMINE DEGRADATION PRODUCTS
FROM CARBON SEQUESTRATION PROCESSES.
V. Naik 1 , J. McDonald 1 , M. Doyle-Eisele 1 , E. Knipping 2 and A. Rohr 2 .
1 Lovelace, Albuqueruque, NM and 2 Electric Power Research Institute, Palo Alto, CA.
There is currently an unmet need in understanding potential unintended health effects
of exposure to amines that are utilized for CO2 capture in industrial operations.
Because the processes utilize large volumes of amines, there is a chance for
“slip” of these compounds and emission to the atmosphere. Furthermore, because
the amines are utilized under highly oxidative conditions, there is potential for
emissions of their degradation products. An experimental system has been developed
to study the inhalation hazard of these amines and their degradation products.
Monoethanolamine (MEA), a representative amine that may be used in this
process, was used in initial studies conducted to assess potential hazard. The
gaseous head space was obtained from the canister and delivered to a whole-body
inhalation system or a reaction canister. Initial inhalation exposures to MEA were
conducted at 18 mg/m3. Exposures were conducted in C57bl/6 mice 6h/day for 7
days. Toxicity was assessed by lavage counts/differentials, cytokine upregulation,
and oxidative injury. The response to MEA atmosphere is compared with MEA
that is degraded under conditions that simulate carbon capture processes. This includes
both the addition of heat to ~150°C and the addition of oxygen, carbon
dioxide and NOx. The reactions are conducted in a slightly pressurized non-adsorbent
stainless steel canister. Reaction products are analyzed by mass spectrometry.
The mixture is subsequently diluted and used for inhalation toxicity studies that
compare to the hazard of MEA. Initial hazard evaluation or MEA degradation
products are benchmarked against MEA atmospheres, which showed s mild inflammation
at MEA atmospheres ≥ the occupational exposure limit. Research supported
by the Electric Power Research Institute.
595 TRACHEOBRONCHIAL AIRWAY MORPHOMETRY FOR
THE C57BL/6 MOUSE: IMPLICATIONS IN INHALED
DOSIMETRY PREDICTIONS.
L. B. Mendez 1, 2 , R. F. Phalen 2 and G. J. Ramirez 3 . 1 Microbiology and Molecular
Genetics, University of California, Irvine, Irvine, CA, 2 Medicine, University of
California, Irvine, Irvine, CA and 3 East Los Angeles College, Monterey Park, CA.
The availability of molecular and genetic tools has made the mouse the most common
animal model for a variety of human diseases. Among the factors that will influence
dose delivery into murine lungs during an inhalation toxicology study are
SOT 2011 ANNUAL MEETING 127