Environmental and Molecular Mutagenesis - Legacy Tobacco ...

40 1989 EMS Abstracts
Notes lymphoma assay [MtA)) ; and (g) Implies the existence of penotoxicJcarcinopenic chemical structures
different from those Implicated in DNA reactivity . The cytopenet)c and molecular mutational spectra of a
number of chemically diverse mutagens In the MLA Indicates that only a few mutagens (e .y., EMS,
2-amino-6N-hyd(oxyadenine) Induce a significant proportion of subgenic DNA alterations at the
heterozypous tk locus, whereas most Induce predominantly DNA alterations which are at least many
kilobases (and probably multigenic) in extent (Glover et al ., these abstracts) . These results will be
discussed In terms of penotoxicity models and mechanisms which Indude non-DNA targets .
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
110
MUTAGENIC ACTIVITY OF EXTRACTS FROM ROLLING MINERAL OILS AND LEATHER SAMPLES .
E . Cionferot, P . Venier=, M . iordanz and A .G . Levis= . t Inst . Occup . Health
University of Padova (ITALY) 2 Dept. of Biology, University of Padova (ITALY) .
Unused crank case oils are norsally negative in the Salmonella/sicrosose assay
but become strongly sutagenic after use due to the enrichment of their PAH content
resulting from engine cosbustion processes . On the other hand refined rolling oils
lack sutagenic activity even after prolonged use because of the low temperature
working conditions . Finished leather probably contains naturally occurring tannins,
but other chemical compounds used in the tanning and refining processes may also
play a part in determining the carcinogenicity of soae leather dusts . We evaluated
the sutagenicity (in the Saleonella/ .icroso.e assay) of extracts fro . a aineral oil
esulsion used in a rolling ∎ill and from finished leather . ' The oil emulsion was
suspended in DMSO and extracted with CHzCl= . The extracts fros the unused oil were
negative, while after prolonged use sutagens directly active on Salmonella strains
TA98 and TAIOO were found (8-10 ind . rev ./ .g eq . of extract) . Relatively low
concentrations of oil (10 ∎g/plate) were found to inhibit totally the .utagenicity
of 5 pg of benzo(a)pyrene assayed in the presence of S9 . " After treatment in a
Soxhiet apparatus with toluene or ethanol the extracts from a leather widely used in
the furniture and dresssaking Industries were mutagenic on strain TA98 of 3,
j,yphisurius in the absence of S9 ∎ix . The analysis of the extracts from leather at
various intersediate stages of processing showed that the mutagenic activity
appeared after the coloration process . The responsible compound was identified to be
an azodye (Color Index : Acid Brown 83, .utagenic potency about 4
revertants/sicrogras) . SUPPORTED BY C .N .R . p .f . "ONCOLOGIA" .
111
THE MUTAGENICITY OF 2-AMINO-N6-HYDROxYADENINE (ASA) TO L517BY TK+/- CELLS MEASURED
BY THE INDUCTION OF TRIFLUOROTHYMIDINE (TPT), 6-TBIOGUANINE (6TG) AND OUABAIN (OUA)
RESISTANCE AND THE INDUCTION OF MICRONUCLEI .
Jane Cole, Frances Richmond and Bryn Bridaes, MRC Cell Mutation Unit, University of
Sussex, Brighton BN1 9RR, Gt . Britain .
L5178Y TK+/- (3 .7 .2c) cells were treated with AHA at concentrations ranging from
0 .005 to 2 .Oµq ml-1 (100 - 15% survival) . Samples were plated on day 0 after treatment
to determine the toxic effect, on days 2 and 3 to determine TFT and OUA mutant
frequency and on day 7 to determine 6TG mutant frequency . All platinqs were done by
the microtiter method of Cole at al . (1986, Mutaqenesis 1, 157-167) . Slides were
prepared 24h and 48h after treatment to determine the induction of micronuclai (MN) .
Positive controls (ethyl or methylmethanesulphonate) were included in every experiment
. Over the non-toxic range (0 .01 - 0 .04µq/ml, 80 - 100% survival) there was
approximately linear induction of TFT, OUA and 6TG resistance . At toxic concentrations,
TFTR continued to increase with dose, 6TG resistance plateaued at around 0 .5µq
/ml, and a peak of OUAR mutants was observed at 0 .25µq/ml, at higher doses there was
a marked decrease in OUA resistance . Only small increases in the percentage of MN
were observed .
112
A NEW METHOD FOR PREPARATION OF METAPHASES FROM THE G .I . TRACT OF RODENTS . Barbara
Coles, Leslie McSparrin, Judith Horvath, and William S . Barnes, Department of Biology,
Clarion University of PA, Clarion, PA .
Research has frequently been handicapped by the lack of a good experimental
system to study the events of colon carcinogenesis . Carcinogenic activity can
be identified by induction of SCE, but it remains difficult to obtain good yields
of mitotic cells from the G .I . tract . In our protocol, 35 g . male C57BL/6 mice
were implanted with a 25 mg agar-coated BrdUrd tablet . Twenty-three hours later,
they were injected i .p . with 10 mg/kg coichicine . Twenty-five hours after BrdUrd
adminsitration, animals were anesthetized and a loop of small intestine was exposed
from the body cavity . The loop was cut from both ends, being careful not to cut
any blood vessels, and fecal material was flushed out . The segment was then treated
sequentially with two incubations of 0 .5mM EDTA, followed by two incubations of
collagenase in 10mM HEPES (750 units/ml .) . The segment was removed from the animal .
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