The Toxicologist - Society of Toxicology

922 A STUDY OF PHOTOTOXICITY FOLLOWING
INTRAVENOUS ADMINISTRATION TO BALB/C MICE.
Y. Yamashita, S. Utsunomiya, Y. Takahashi, T. Ichii, Y. Otsubo, T. Nakamura,
H. Izumi, T. Sukamoto and R. Nagata. Drug Safety Research Laboratories, Shin
Nippon Biomedical Laboratories, Ltd., Kagoshima, Kagoshima, Japan.
[Purpose] The in vitro 3T3 NRU phototoxicity test is described in OECD guideline
TG 432, but there is no in vivo phototoxicity test guideline. We reported (2008
SOT) on an oral administration in vivo phototoxicity test. Here, we evaluate the
phototoxicity of ciprofloxacin hydrochloride (CPFX) and 8-methoxypsoralen (8-
MOP) in Balb/c mice following intravenous administration because there is little
information about in vivo phototoxicity studies. [Method] CPFX and 8-MOP were
used as phototoxic substances. Male BALB/c mice, aged 6 weeks, were used. On the
day before administration, the backs of the mice were shaved. The dosing preparations
(50 and 100 mg/kg CPFX, and 5 and 10 mg/kg 8-MOP) were administered
at 20 (CPFX) or 1 (8-MOP) mL/kg. Ten minutes after administration, the animals
were irradiated with long-wave ultraviolet rays of approximately 20 J/cm2 with an
Ultraviolet Irradiation Apparatus (Dermaray, M-DMR-50, Eisai Co., Ltd.). The
thickness of both ears was measured with a dial thickness gauge, and the ears and
back skin were observed before administration and at 0.5, 24, 48, and 72 hours
after irradiation. Skin reactions (erythema and edema) at the ear and back were
evaluated in accordance with the Draize method criteria. At 72 hours after irradiation,
the ear and back skin were prepared for histopathology (Hematoxylin-Eosin
stain). [Results] In the 50 and 100 mg/kg CPFX and 5 and 10 mg/kg 8-MOP
groups, erythema or edema scored as 1 or 2 was observed at the irradiated sites. Ear
thickness was increased in the 100 mg/kg CPFX group, and in the 5 and 10 mg/kg
8-MOP groups after irradiation. In histopathology, findings such as degeneration,
edema, hemorrhage, and inflammatory cell infiltration were noted in the 100
mg/kg CPFX group and in the 5 and 10 mg/kg 8-MOP groups. In this study, positive
reactions were clearly observed, and it was considered that the evaluation was
possible in the intravenous administration in vivo phototoxicity test.
923 DEVELOPMENT OF A WEANLING PIG MODEL OF
CUTANEOUS INJURY INDUCED BY CHLORINE VAPOR.
R. C. Kiser 1 , M. R. Perry 1 , F. M. Reid 1 , J. L. Plahovinsak 1 , T. H. Snider 1 , M.
C. Babin 1 , J. A. Blank 1 and J. S. Graham 2 . 1 Battelle Biomedical Research Center,
Columbus, OH and 2 U.S. Army Medical Research Institute of Chemical Defense,
Aberdeen Proving Ground, MD.
Due to continued public concern for safety from chemical attacks, the Battelle
Biomedical Research Center (BBRC) and the U.S. Army Medical Research
Institute of Chemical Defense (USAMRICD) have aligned research efforts to establish
an anesthetized weanling pig model of superficial dermal and deep dermal
cutaneous injuries induced by chlorine vapor. A chlorine vapor exposure system was
fabricated and characterized to evaluate four lesion sites (each 3 cm in diameter) between
the axillary and inguinal areas of the ventral abdomen in female Yorkshirecross
weanling pigs. Lesion assessment included clinical observations, digital photographs,
size measurements, modified Draize scoring, reflectance colorimetery,
evaporimetry, and infrared thermographic images. Histopathologic evaluation of
skin collected at 48 hours post-exposure included wound severity, wound depth,
and percent of the total area involved. Saturated chlorine vapor at 2.9 g/L for 30
min did not induce dermal lesions on the ventral abdomen. Adding a wetted (simulated
sweat) material (fabric or filter paper) onto the abdominal skin sites and exposing
for 30 min to saturated chlorine vapor induced superficial dermal injuries
and the material had dried. Using wetted filter paper discs placed on each exposure
site for a saturated chlorine vapor exposure of 30 and 60 minutes, lesions were characterized
and confirmed clinically and histologically at 48 hours, to be superficial
dermal in severity. It is hypothesized that humidified chlorine vapor exposure experiments
may be able to create a deep dermal lesion and these studies are currently
underway. This work was supported by the U.S. Army Medical Research and
Materiel Command under Contract W81XWH-05-D-0001, Task Order 0010.
924 EFFICACY AND TREATMENT OPTIMIZATION OF
ANTI-INFLAMMATORY DRUGS APPLIED TO
CUTANEOUS SULFUR MUSTARD INJURIES IN A
WEANLING PIG MODEL.
J. L. Plahovinsak 1 , F. M. Reid 1 , R. C. Kiser 1 , M. C. Babin 1 , J. A. Blank 1 , N. M.
Gargas 1 and J. S. Graham 2 . 1 Battelle Biomedical Research Center, Columbus, OH
and 2 U.S. Army Medical Research Institute of Chemical Defense, Aberdeen Proving
Ground, MD.
An agreement between the National Institute of Health (NIH), Battelle Biomedical
Research Center (BBRC), and the U.S. Army Medical Research Institute of
Chemical Defense (USAMRICD) supports efficacy testing and treatment optimization
of candidate drugs to improve wound healing against chemical agents of
public concern. This study assessed the efficacy and treatment optimization of two
NSAIDs (capsaicin 0.075% and diclofenac sodium 3%) with clobetasol propionate
0.05% applied topically to one site of two depths of injury, superficial dermal (SD)
and deep dermal (DD), induced by sulfur mustard (HD). Fifty-four female,
Yorkshire-cross pigs were randomly assigned to experimental groups representing
all combinations of treatment duration (1, 3, or 5 days), daily number of applications
(2, 3, or 4), and onset time (1, 2, or 4 h post-exposure) for each NSAID with
steroid. Each of four ventral abdominal sites per pig had 400 μl of undiluted HD
applied topically (2 sites 8 min exposure for SD injuries and 2 sites for 30 min DD
injuries). Treatments were applied to one site per depth of injury at the respective
time post-exposure; the untreated sites served as within-animal controls. Site assessments
included digital photographs, lesion size measurements, modified Draize
Scoring, and non-invasive bioengineering techniques (reflectance colorimetry, infrared
imagery, and transepidermal water loss). Histopathologic evaluations were
performed for wound healing parameters (re-epithelialization, dermal necrosis, and
fibroplasia). Diclofenac sodium with clobetasol showed the most promise of healing
HD-induced lesions. Both NSAID treatments provided improved healing of
HD-induced lesions as the frequency and duration of treatment increased.
This work was supported by the U.S. Army Medical Research and Materiel
Command under Contract W81XWH-05-D-0001, Task Order 0010.
925 TRI-SPECIES COMPARISON OF RESPIRATORY
MECHANICS: BEAGLE DOGS, GöTTINGENS MINIPIGS
AND CYNOMOLGUS MONKEYS.
R. Mikaelian 1 , L. Gold 3 , A. Robichaud 3 , E. Troncy 2 and S. Authier 1, 2 . 1 LAB
Research Inc., Laval, QC, Canada, 2 Faculty of Veterinary Medicine, University of
Montréal, Montréal, QC, Canada and 3 SCIREQ Scientific Respiratory Equipment
Inc., Montréal, QC, Canada. Sponsor: G. Washer.
When the NOAEL is determined by respiratory safety pharmacology, follow-up
studies are warranted and may include airway resistance and compliance.
Respiratory mechanics in large animal species commonly used in safety pharmacology
studies (Beagle dogs, Göttingens minipigs and Cynomolgus monkeys) were
compared. Eighteen animals were used (3/sex/species) in an anesthetized model
(propofol infusion) with pancuronium as a neuromuscular blocker and neostigmine
for reversal. Parameters of respiratory mechanics were evaluated at baseline
and at peak drug effect. The testing protocol included single-frequency forced oscillation
analyzed with a single compartment model in which resistance, elastance
and compliance were calculated. Increasing doses of methacholine (2.32 to 263.5
μg/kg) were given by inhalation and the PD200, defined as the dose inducing a
200% increase in resistance, were calculated at baseline and after administration of
albuterol by inhalation. Baseline PD200 was not significantly different in all 3
species.In minipigs, albuterol induced a mild to moderate increase (+33.4% ±
13.6%) in PD200 while a moderate to severe increase was noted in dogs (+284.8%
± 133.1%) and monkeys (+402.3% ± 90.8%). The increase in PD200 was significant
in all species. Abundant scientific literature is available on respiratory mechanics
in cynomolgus monkeys and Beagle dogs. In contrast, limited historical data is
available in minipig respiratory mechanics. Our results suggest that dogs and monkeys
were sensitive to albuterol administered by inhalation while minipigs were less
sensitive.
926 CORRELATION OF FUNCTIONAL AND
MORPHOLOGIC CHANGES IN A MOUSE MODEL OF
EMPHYSEMA.
K. Lee, K. M. Gideon, S. J. Harbo, J. T. Pierce, J. C. Blessing, L. A. Wisse and
B. D. MacIsaac. Toxicology NW, Battelle, Richland, WA.
There is a growing interest in detecting functional decline in lung mechanics of animal
models of the chronic obstructive pulmonary disease (COPD). Changes in
pulmonary function, which include alterations in lung compliance and elastance,
may serve as non-invasive early indicators of disease progression. In this study we
induced emphysema, which is a core feature of human COPD along with chronic
bronchitis, via elastase instillation. Lung function, morphometry, and histopathology
were evaluated post dosing. Female C57BL/6 mice (N=8-10/group) were subjected
to a single oro-tracheal instillation of elastase (40 U/kg; 0.06 mL) or PBS
(sham). At Week 1 and 3 postdosing, lung function was measured using the
flexiVent® system. Lungs were removed, weighed, and the left lung was fixed for
microscopic examination. Quantitative assessment of emphysema (airspace enlargement)
was estimated by calculating the mean chord length using Image-Pro Plus®.
All mice were unremarkable postdosing and survived until the Week 3 sacrifice.
However, the elastase-treated mice had higher dynamic compliance and lower tissue
elastance compared to the sham control at both time points. This functional change
correlated with histopathological observations of emphysema in treated mice which
SOT 2010 ANNUAL MEETING 197