The Toxicologist - Society of Toxicology

cells. Given the importance of trophoblast-derived cytokines in pregnancy, further
research is warranted to ascertain potential relevance of these findings to human
health.
1057 OXIDANT-INDUCED INFLAMMATORY RESPONSE IN
HUMAN PLACENTAL CELLS IS DEPENDENT ON
MITOGEN ACTIVATED PROTEIN KINASES (MAPKS).
C. S. Korte and R. Loch-Caruso. Environmental Health Science, University of
Michigan, Ann Arbor, MI.
Preterm birth is associated with significant infant morbidity and mortality.
Although the etiology of preterm birth is not fully understood, it is well-established
that labor is induced by inflammatory activity within the gestational compartment.
Labor also is associated with markers of oxidative stress within gestational tissues,
but the impact of oxidative stress on labor-promoting pathways has received little
attention. The present study examined the effect of oxidative insult, in the form of
tert-butyl hydroperoxide (TBHP) exposure, on MAPK-dependent inflammatory
cytokine release from placental cells using the human extravillous trophoblast cell
line HTR-8/SVneo. HTR-8/SVneo cells were treated with 12.5, 25 or 50μM
TBHP for 2, 6 or 24 h in the presence or absence of pharmacological MAPK inhibitors.
Cytokine release was then measured by specific ELISA. At 24 h, 50 μM
TBHP induced a significant 2.5-fold increase in interleukin (IL)-6 release into the
culture medium, but IL-8 release was not significantly affected. Inhibition of p38
MAPK and ERK1/2 but not JNK decreased TBHP-induced IL-6 release. In contrast,
exposure to the endotoxin lipopolysaccharide (LPS) stimulated release of both
IL-6 and IL-8, but release of IL-6 and IL-8 was dependent on p38 MAPK alone.
Further research is needed to understand the implications of the differential MAPK
pathway activation and cytokine release elicited by TBHP compared with LPS.
Nonetheless, these data indicate that oxidative insult induces inflammatory cytokine
release from trophoblast cells by specific MAPK pathways. Because elevated
amniotic fluid concentrations of IL-6 are strongly associated with preterm birth in
women, toxicant exposures that induce oxidative stress within the gestational compartment
may pose a risk for pregnancy.
1058 REGULATION OF HUMAN PLACENTAL DRUG
TRANSPORTERS IN RESPONSE TO BACTERIAL CELL
WALL COMPONENTS.
L. Yacovino 1 , A. Vetrano 2 , N. Hanna 3 and L. M. Aleksunes 1 . 1 Pharmacology &
Toxicology, Rutgers University, Piscataway, NJ, 2 Pediatrics, University of Medicine
and Dentistry of New Jersey, New Brunswick, NJ and 3 Pediatrics, Winthrop
University Hospital, Mineola, NY.
Efflux drug transporters within the placenta are key defense mechanisms for limiting
fetal exposure to xenobiotics. Placental drug efflux transporters include isoforms
of the Multidrug Resistance-Associated Protein (MRP) family as well as the
Multidrug Resistance Protein 1 (MDR1) and the Breast Cancer Resistance Protein
(BCRP). Two chemicals of particular interest are lipoteichoic acid (LTA) and
lipopolysaccharide (LPS), both components of bacteria able to initiate an inflammatory
response and potentially regulate drug transporter expression within the
placenta. The purpose of this study was to quantify changes in transporter mRNA
expression in term human placentas 24 h after ex vivo LPS and LTA exposure.
Preliminary mRNA analysis demonstrated a 2-fold increase in TNF-alpha cytokine
mRNA as well as elevated levels of MRP2 mRNA in LPS- and LTA-exposed placentas.
Expression of BCRP and MRP1 mRNA was variable among placentas and
unchanged by LPS and LTA treatment. MDR1 and IL-6 mRNA levels were below
the level of detection. Additional studies are underway to quantify time-dependent
changes in transporter mRNA and protein expression in response to LPS and LTA
stimulation in additional human placentas. In addition, transcriptional and epigenetic
mechanisms by which changes occur in mRNA and protein expression will be
investigated. Altered expression of placenta drug transporters during periods of infection
and inflammation may alter the maternal-fetal disposition of endogenous
chemicals and toxins (Supported by ES-007148 & ES-005022).
1059 ALCOHOL DRINKING-PROMOTED ACETALDEHYDE
ACCUMULATION AND OXIDATIVE STRESS IN RAT
TESTES.
G. D. Castro, L. N. Quintans, F. M. Bietto, M. I. Díaz Gómez and J. A. Castro.
Ceitox, Conicet-Unsam, San Martín, Buenos Aires, Argentina.
Excessive alcohol consumption is associated with impaired testosterone production
and testicular atrophy. Similar findings were observed in in vitro studies on the
testosterone production by isolated testes, being acetaldehyde (AC) more potent
226 SOT 2011 ANNUAL MEETING
than alcohol in suppressing testosterone release. In previous studies we reported
that rat testicular microsomes were able to bioactivate ethanol to AC, 1-hydroxyethyl
and hydroxyl radicals. Now we report that after a single dose of ethanol (3.8
gr/kg, ig.), AC accumulates in testicular tissue for prolonged periods of time (about
9 hours). Comparison against alcohol or AC concentrations in blood and liver tissue
up to 24 hours suggests that AC generation in situ is determinant for this cumulative
effect. We also observed that testicular cytosolic ADh, xanthine oxidase
and AldDh activities were very low or undetectable by histochemical procedures.
Six hours after that single dose of ethanol the testicular levels of lipids hydroperoxides
(xylenol orange method) were significantly increased. Similar observations
were made in testes from animals receiving a standard Lieber and De Carli diet during
28 days. We also tested twenty four polyphenols having known antioxidant
properties against the NADPH dependent and the NADPH non-dependent microsomal
metabolism of alcohol to AC. Some of them exhibit significant inhibitory
effects at low concentrations (10-50 micromolar) on both metabolic processes.
Results suggest that in situ microsomal metabolism of alcohol to AC and the low
AldDh activity present at the testicular tissue might be involved in the AC accumulation
observed, and that our previously reported alcohol-promoted generation of
1-hydroxyethyl and hydroxyl radicals might initiate the lipid peroxidation process
leading to production of the lipid hydroperoxides detected in vivo. Ability of
polyphenols to inhibit these microsomal pathways of alcohol metabolism at low
concentrations suggest preventive effects of them against alcohol induced testicular
damage and reproductive impairment, that remain to be established.
1060 NONHUMAN PRIMATE POSTNATAL DEVELOPMENT:
HISTORICAL CONTROL DATA IN NONCLINICAL
TOXICOLOGY STUDIES.
N. Lalayeva 1 , J. Kenfield 1 , J. Cowan 2 , S. Oneda 1 , N. Makori 1 , R. Eyre 1 , H.
Tsusaki 1 and R. Nagata 3 . 1 SNBL USA, Ltd., Everett, WA, 2 Consultant for NHP
Infant Behavior, San Francisco, CA and 3 Shin Nippon Biomedical Laboratories, Ltd.,
Kagoshima, Japan.
Extended functional and morphological evaluations of infant nonhuman primates
are essential components of pre-/post natal developmental toxicology studies based
on addendum to ICH 6S (R1) guideline. The aim of this study is to present comprehensive
historical control background data collected in infants up to seven
months post delivery. Infants were evaluated using the following tests under GLP
conditions: incidence of mortality at natural delivery, external teratological examination
at birth, skeletal development (post-natal day [PND] 30), external morphometrics
(PNDs 3, 30, and 95), behavioral assessment (PNDs 45, 105, and 195),
body weights (weekly), and learning and memory using a Wisconsin General
Testing Apparatus (WGTA). Incidence of stillbirths by study ranged from 0% to
17.6%, with no correlation to gestation day of birth. Average infant body weights
(genders combined) at birth were 323.3 g (220.4 g to 441.8 g) and 404.4 g (276.0
g to 510.4 g) one month after birth. No abnormalities were observed during external
morphological or skeletal examinations. Similarities in behavioral characteristics
were demonstrated in >90% of infants. WGTA testing showed the number of sessions
to criterion for the training phase to be 5 (range 2 to 11), 13 (range 4 to 26)
for the learning phase, and 6 (range 3 to 12) for the 9 out of 17 animals that completed
the first reversal. The number of reversals completed within the 30-session
series was on average 2 (range 0 to 7). In conclusion, robust control background
data is a useful reference tool for results interpretation in pre-/postnatal reproductive
toxicology studies.
1061 MENSTRUAL CYCLE AND SERUM HORMONE DATA IN
MATURE CYNOMOLGUS MONKEYS.
S. Oneda 1 , N. Lalayeva 1 , R. Watoson 1 , N. Makori 1 , R. Eyre 1 , H. Tsusaki 1 and
R. Nagata 2 . 1 SNBL USA, Ltd., Everett, WA and 2 Shin Nippon Biomedical
Laboratories, Ltd., Tokyo, Japan.
Introduction: The cynomolgus monkey (Macaca fascicularis, Mfl) is a useful animal
model for nonclinical developmental and reproductive toxicity studies of biopharmaceuticals.
Female fertility can be assessed in a repeated dose toxicity study
using sexually mature monkeys [ICH Guideline S6 (R1)], and menstrual cyclicity
is one of the critical parameters. The goal of this presentation is to establish normal
range of menstrual cycle (MC) length and criteria of abnormal cycles in Mfl. Serum
17-beta estradiol (E2) and progesterone (P4) concentrations during normal and abnormal
cycles were also evaluated. Methods: Total of 447 MC from 93 Mfl were
evaluated. Number of MC evaluated for each female ranged from 2 to 7 (mean =
4.8). Mean value of the first two cycles was treated as baseline cycle (BC). Following
cycles (Study Cycle, SC) were compared with BC. Samples for E2 and P4 were collected
every 2 to 7 days during MC, and were analyzed using ELISA method.
Profiles of E2 and P4 during normal (22 to 38 days) and prolonged (50 to 92 days)
MC were compared.