Grantee Research Project Results
2004 Progress Report: Animal Models: Dosimetry, and Pulmonary and Cardiovascular Events
EPA Grant Number: R827354C004Subproject: this is subproject number 004 , established and managed by the Center Director under grant R827354
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Rochester PM Center
Center Director: Oberdörster, Günter
Title: Animal Models: Dosimetry, and Pulmonary and Cardiovascular Events
Investigators: Oberdörster, Günter , Zareba, Wojciech , Elder, Alison C.P. , Morrow, P. E. , Utell, Mark J. , Finkelstein, Jacob N. , Frampton, Mark W. , Kittelson, David , Couderc, Jean-Philippe , Tieu, Kim , Gelein, Robert , Eberly, Shirley , Silva, Vanessa
Current Investigators: Oberdörster, Günter , Elder, Alison C.P.
Institution: University of Rochester
EPA Project Officer: Chung, Serena
Project Period: June 1, 1999 through May 31, 2005 (Extended to May 31, 2006)
Project Period Covered by this Report: June 1, 2004 through May 31, 2005
RFA: Airborne Particulate Matter (PM) Centers (1999) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Particulate Matter , Air
Objective:
The objective of this research project is to use animal studies to focus on factors such as particle size, dosimetric aspects (lung deposition and disposition), and host susceptibility (advanced age; cardiovascular disorders). Exposures were to laboratory-generated model particles and particles on highways.
Progress Summary:
Truck Study II
We previously reported results from a series of studies using the mobile emissions laboratory (MEL) from the University of MN in which exhaust aerosols from surrounding vehicles were entrained into the trailer for animal exposures. This report provides additional analyses from this second series of studies. We had ensured more continuous aerosol sampling (that was independent of other traffic) by placing inlet pipes at the end of the trailer that allowed sampling of the diluted engine exhaust plume emitted from the front of the tractor. We exposed old rats (20-22 mo. F-344) to freshly generated highway aerosols (particles (< 1 μm)/gas phase, gas phase only, or filtered air) using this modified system. Rats were treated with inhaled endotoxin or instilled influenza virus either before or after on-road exposures to prime respiratory tract cells. Exposures (6 hr; 1 or 3 days in a row) in compartmentalized whole-body chambers occurred while driving between Rochester and Utica (NY I-90). The primary particle size was 13-19 nm, and the number concentration was 1.6-4.3 x 106/cm3, about twice as high as in the previous study. The particle number, along with NO and CO2, concentrations in the incoming air indicated that the MEL exhaust plume was being directly sampled at a dilution of about 400:1.
The particle/gas-phase mixture caused an increase in plasma fibrinogen within 24 hrs of exposure in influenza-exposed old rats. When the evaluation period was 3 days after aerosol exposure, the mixture caused decreases in fibrinogen. Regardless of priming agent, length of exposure, or length of recovery period, small increases in ICAM-1 surface expression on AMs were found due to the particle/gas-phase mixture. The data also suggest greater message expression for TNF-α and its receptor in lung, heart, and olfactory tissue from those rats exposed to the particle/gas-phase mixture. The effects of the particle/gas-phase mixture were slightly greater and more persistent than those of the gas phase alone. Compared to previous studies in MEL in which the particle number and gas concentrations were lower and less continuous (Elder, et al., 2004; Kittelson, et al., 2004), we observed more pronounced effects of freshly generated vehicle exhaust aerosols, and the specific effects and the directions of the responses were consistent with the earlier study. These results show that freshly generated exhaust aerosols have significant effects on the pulmonary and cardiovascular systems and potentially the central nervous system in compromised, old rats.
Mn Solubility
As we reported previously, inhalation of ultrafine Mn-oxide particles (CMD = 33 nm) resulted in significant accumulation of Mn in the olfactory bulb of rats; the translocation occurred via the olfactory nerve, as verified in a rat inhalation study with the right nostril occluded, which resulted in Mn accumulation in the left olfactory bulb only. A question regarding the solubility of Mn-oxide in the neutral pH of the nasal mucosa was raised. A series of experiments was conducted to determine the solubility of ultrafine Mn oxide particles in NaCl at neutral pH so that results from inhalation and intranasal instillation studies could be better interpreted. Initial losses of Mn into the aqueous phase were approximately 10 percent, depending on Mn oxidation state (Mn(II), Mn(III)). However, after centrifugation of the initial suspension and resuspension of the particle pellet in NaCl, there was only approximately 4 percent of Mn detectable in the supernatant, indicating very low solubility of Mn-oxide at neutral pH. Although it is not clear whether the signal arises from soluble Mn or from the smallest of the ultrafine (UF) Mn oxide particles that could not be sedimented by gravitational force during centrifugation, residual Mn remained stable up to 7 days in solution. The amount of oxygen entering the PALAS ultrafine particle generator only minimally affected particle size.
Neuronal Mn Translocation
A comparison of the translocation of ultrafine Mn-oxide and MnCl2 to the olfactory bulb was performed following intranasal instillation of test materials. After a period of 24 hrs, less than 50 percent of the applied Mn remained in the olfactory mucosa and olfactory bulb. Two to three times more Mn was retained in the cribriform plate as compared to the olfactory bulb; olfactory bulb retention was approximately 10 percent of the amount applied regardless of molecular structure, indicating translocation of the Mn-oxide as solid particles. Slightly more Mn was retained in the cribriform plate when MnCl2 was instilled.
Mn/MPTP Pilot Study
This pilot project was conducted to get preliminary data for future studies focusing on the potential neurotoxic effects of inhaled ultrafine particles in a model of neurodegeneration (MPTP). Mice were exposed to ultrafine MnO2 for 3 weeks, after which they were exposed to MPTP to cause injury to dopaminergic neurons in the nigrostriatal regions of the brain. As indicators of this injury, the levels of tyrosine hydroxylase (TH) were measured in striatal tissue following the exposures. Neither Mn nor MPTP alone significantly lowered striatal TH levels; however, when MN and MPTP were combined, significant reductions were found, suggesting an impairment in the production of dopamine in this brain region. Neither exposure component had any effect on BAL parameters of inflammation and cytotoxicity.
Neuronal Translocation of Gold Nanoparticles
A series of studies was conducted in which 5 and 20 nm Au nanoparticles were instilled into the left naris to determine their translocation to the olfactory bulb and if this process was affected by primary particle size. First results show that more of the 5 nm gold particles compared to the 20 nm ones reached the olfactory bulb. Coating the gold particles with albumin seems to increase their translocation. Comparing these results to those with Mn, it still remains to be determined what factors control translocation into the brain.
Ear Vein Thrombus Formation
We previously reported on results from systemic injection and intratracheal instillation studies showing that ultrafine particles decrease the thrombus formation time in rat ear veins following their illumination with green laser light. We are continuing these studies, this time exposing the animals to ultrafine carbon particles via whole-body inhalation. As with the previous studies, we also observed a decrease in thrombus formation time in rat ear vein following inhalation of either 70 or 200 μg/m3 ultrafine carbon. Interestingly, the results showed a greater effect of the lower doses, which may be due to formation of larger aggregates when higher doses are administered. Currently, we are developing a system to evaluate the growing thrombus using an image analysis system so that evaluations are less subjective.
Future Activities:
The studies with the Harvard Ultrafine Particle Concentrator (HUCAPS) at the University of Rochester were planned for early 2005; however, they were unexpectedly delayed because a chilled water line in the dedicated HUCAPS room of our new Medical Research Building was not extended and connected to the main water line at the time of building construction. This issue has been resolved so that these studies will now begin. Initial characterizations of the concentrator performance were successfully accomplished, and results have been submitted for publication. We have, however, conducted test runs with ambient traffic-related aerosols in Rochester to characterize system performance. The goal was to collect sufficient data on the daily variability in UFP number concentration so that we can begin single and repeat exposures of JCR rats to traffic-related UFP (will measure endpoints related to lung inflammation and acute exacerbations of cardiovascular stress). The data collected over several days shows that there are two number concentration peaks during each day from approximately 6:00 a.m.-12:00 noon and approximately 6:00-9:00 p.m.
The JCR rats themselves are not readily available because they do not breed rapidly, and only the homozygous males are diabetic and obese with the attendant cardiovascular complications that mimic human type II diabetes. We were able to obtain a set of 20 males over the period of several months, and have used some of these rats to measure blood parameters related to diabetes and to compare to results published by Dr. James Russell, the originator of this rat model. In initial characterization studies, we found that the blood glucose levels in the JCRs are high and correlate well with reported findings by Russell, et al. (1998) in the same strain and in human diabetics, as reported by Zareba, et al. (2001). Other animals from the same group were used to further characterize the model by exposing them to ultrafine carbon particles generated by electric discharge in the laboratory. We found that, in general, these rats tolerated compartmentalized whole-body exposures well, although there was an increase in lavage fluid lactate dehydrogenase that we cannot currently explain. We also are evaluating flow cytometry data to determine if circulating microparticles derived from platelets and endothelial cells can be identified. We now are ready to begin exposures of JCR rats to the traffic-related UFPs. Comparisons will be made with heterozygous lean males of the same strain that we recently obtained.
Journal Articles:
No journal articles submitted with this report: View all 33 publications for this subprojectSupplemental Keywords:
pollution prevention, urban air pollution, atmosphere, metals, air, health, waste, atmospheric sciences, biochemistry, children’s health, environmental chemistry, epidemiology, genetics, virology, molecular biology, health risk assessment, risk assessments, incineration, combustion, combustion engines, air toxics, tropospheric ozone, PM2.5, particulates, ultrafine particles, particulate matter, particle exposure, particle size, aerosol, aerosols, ambient air, ambient air monitoring, ambient air quality, animal model, atmospheric, cardiopulmonary, cardiopulmonary responses, cardiovascular disease, cardiovascular vulnerability, coronary artery disease, cytokine production, fine particles, human exposure, human health, human health effects, environmental health effects, inhalation toxicology, lead, lung, lung inflammation, metals, morbidity, mortality, pathophysiological mechanisms, pulmonary, pulmonary disease, stratospheric ozone, sensitive populations, susceptible populations,, RFA, Health, Scientific Discipline, Air, particulate matter, Toxicology, air toxics, Environmental Chemistry, Health Risk Assessment, Risk Assessments, Biochemistry, Atmospheric Sciences, Molecular Biology/Genetics, ambient air quality, cytokine production, particle size, particulates, sensitive populations, biostatistics, health effects, risk assessment, cardiopulmonary responses, fine particles, human health effects, morbidity, ambient air monitoring, lung, cardiovascular vulnerability, pulmonary disease, susceptible populations, animal model, ambient air, environmental health effects, particle exposure, ambient monitoring, particulate exposure, lung inflamation, pulmonary, coronary artery disease, inhalation toxicology, tropospheric ozone, urban air pollution, mortality, urban environment, aerosol, cardiopulmonary, human health, aerosols, cardiovascular disease, ultrafine particles, pathophysiological mechanismsRelevant Websites:
http://www2.envmed.rochester.edu/envmed/PMC/ Exit
Progress and Final Reports:
Original AbstractMain Center Abstract and Reports:
R827354 Rochester PM Center Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R827354C001 Characterization of the Chemical Composition of Atmospheric Ultrafine Particles
R827354C002 Inflammatory Responses and Cardiovascular Risk Factors in Susceptible Populations
R827354C003 Clinical Studies of Ultrafine Particle Exposure in Susceptible Human Subjects
R827354C004 Animal Models: Dosimetry, and Pulmonary and Cardiovascular Events
R827354C005 Ultrafine Particle Cell Interactions: Molecular Mechanisms Leading to Altered Gene Expression
R827354C006 Development of an Electrodynamic Quadrupole Aerosol Concentrator
R827354C007 Kinetics of Clearance and Relocation of Insoluble Ultrafine Iridium Particles From the Rat Lung Epithelium to Extrapulmonary Organs and Tissues (Pilot Project)
R827354C008 Ultrafine Oil Aerosol Generation for Inhalation Studies
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.
Project Research Results
- Final Report
- 2003 Progress Report
- 2002 Progress Report
- 2001 Progress Report
- 2000 Progress Report
- 1999 Progress Report
- Original Abstract
27 journal articles for this subproject
Main Center: R827354
106 publications for this center
91 journal articles for this center