Noninvasive in vivo electron paramagnetic resonance study to estimate pulmonary reducing ability in mice exposed to NiO or C60 nanoparticles.
OBJECTIVE
To develop new methods that can estimate the influences of manufactured nanomaterials on biological systems, the in vivo pulmonary reducing ability of mice that had received inhalation exposures to NiO or C60 nanoparticles was investigated using a 700 MHz electron paramagnetic resonance (EPR) spectrometer.


METHODS
NiO or C60 suspensions were atomized and mice in exposure chambers inhaled the resulting aerosol particles for 3 hours. The exposure conditions, number-based geometric average diameters, and the average number concentration were precisely controlled at almost the same levels for both NiO and C60 nanoparticles. Two days or 2 weeks after exposure, an EPR study was conducted noninvasively. Temporal changes in EPR signal intensity at the target area (ie, lung field) were obtained by the region-selected intensity determination (RSID) method.


RESULTS
NiO nanoparticles significantly suppressed pulmonary reducing ability 2 days and 2 weeks after exposure, but C60 nanoparticles had no such effect.


CONCLUSIONS
This is the first in vivo estimation of the reducing ability in experimental animals exposed to manufactured nanoparticles.
Yokoyama
Hidekatsu
H
National Institute of Advanced Industrial Science and Technology, Tsukuba and Nagoya, Japan. yokohide@iuhw.ac.jp
Ono
Taizo
T
Morimoto
Yasuo
Y
Myojo
Toshihiko
T
Tanaka
Isamu
I
Shimada
Manabu
M
Wang
Wei-Ning
WN
Endoh
Shigehisa
S
Uchida
Kunio
K
D000336:Aerosols; D000818:Animals; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D004867:Equipment Design; D037741:Fullerenes / Q000493:pharmacokinetics*; D019570:Inhalation Exposure; D008168:Lung / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D053758:Nanoparticles; D009589:Nitrogen Oxides / Q000493:pharmacokinetics*
D000336:Aerosols; D037741:Fullerenes; D009589:Nitrogen Oxides; C039900:nitroxyl; C069837:fullerene C60