Environmental and Molecular Mutagenesis - Legacy Tobacco ...

protein is a DNA-dependent ATPase with DNA helicase activity . The role of this
ATPase/helicase in the various RAD3 functions identified remains to be established .
The RAD2 gene is DNA damage-inducible . Following exposure to a variety of DNAdamaging
agents steady-state levels of RAD2 mRNA increase -3-6 fold . Induction is
positively regulated . Cis-acting sequences required for induction have been
identified by deletion mapping and mutants have been isolated that are defective in
induction of RAD2 . The amino acid sequences of the RAD10 and RAD3 genes share
homology with the human excision repair genes ERCC1 and ERCC2 respectively .
Additionally, the RAD10 gene partially camplements the phenotype of mammalian cells
defective in the ERCCI gene . Thus, genes for NER are apparently conserved in
eukaryotes .
177
IN VIVO EVALUATION OF CYCLOACTIVE AND CLASTOGENIC EFFECTS OF BEET ROOT COLORS . N .C . Froes and N . V. Garcia,
TEILC-'UNESP, Seo Jose do Rio Preto, S ;o Paulo, Brazil .
The recent development of food industry has made food additives a relevant cause of human cancer,
particularlydue to the autagenic activity of several synthetic food colors . The knowledge of mutagenic
effect of natural food colors gives scientific support for the replacement of synthetic by natural ones .
Two different forms of beet root colors were tested, the form I without nitrate residues and the form II1
with nitrate residue . The coloring active principle of both extracts is the betanin pigment which gives the
characteristic beet root purple color . llatagenic effects were tested in vivo . The experiments were carried
out with bone marrow cells of males and females Rattus ~norvergi~cus var . star six-seven weeks old, 90-100g
of weight, orally treated with both forms for one wee , w-3tTi- 0 .02 mg and 5 .0 mg of betanin per 100 g of body
weight per day ; the bone marrow material was collected at the 8th day . For the bone marrow cell experiments
two different control groups were established : a negative group of untreated animals and a positive group
of animals treated with 5 .0 mg of cyclophosphamide per 100 g of body weight 24 hours before sacrifice .
Mitotic index (MI), chromosome anomalies (CA) and micronuclei frequencies were recorded . Slides of bone
marrow were analysed in blind tests . There were no differences in MI, micronuclei, and CA frequencies, when
the treated samples were compared with the negative control . The positive control presented a gross MI
reduction and an increased micronucleus and CA frequency. These results suggest that aiie both forms of the
compounds were metabolized and inactivated in non-mutagenic derivates, justifying the absence of S vivo
cycloactive and clastogenic effects . The present results seem to support that beet root color is a sa er
alternative food additive . Economic and technical restraints were not considered .
178
PREDICTION OF POSSIBLE CARCINOGENS, TUMOR-PROMOTERS AND ANTI-TUMOR
PROMOTERS IN THE GLANDULAR STOMACH . C . Furihata and T . Matsushima,
Institute of Medical Science, University of Tok~o, Tokyo (Japan)
An in vivo short-term assay method was developed for prediction of
carcinogens, tumor-promoters and anti-tumor promoters in the glandular
stomach . In this method, test chemicals are administered to male F344
rats . Then tumor-initiating activity is assayed by measuring inductions
of unscheduled DNA synthesis (UDS) and DNA strand scission (by alkaline
elution method), and tumor-promoting activity is determined by measuring
induction of ornithine decarboxylase (ODC) activity and stimulation of
replicative DNA synthesis (RDS) in the glandular stomach mucosa. By
this method five possible glandular stomach carcinogens, glyoxal,
methylglyoxal, diacetyl, 3-diazo-N-nitrosobamethan and 1-nitrosoindole-
3-acetonitrile were identified . Hickory smoke condensate, with or
without treatment with nitrite, was found to be a possible glandular
stomach carcinogen . In addition, 20 possible glandular stomach tumor
promoters were identified, including various sodium salts, potassium
salts, and an ammonium salt of food additives and bile acids . CaC12 was
found to be a possible anti-tumor promoter in the glandular stomach : its
administration inhibited stimulation of replicative DNA synthesis
induced by subsequent administration of NaCl, a tumor promoter in the
glandular stomach .
179
IN VIVO MUTAGENICITY TESTS ON POLYPLOID INDUCERS
Furukawa,A ., Ohuchida,A . and Wierzba,K .*
Drug Safety Research Lab . and * Biological Research Lab ., Taiho Pharmaceutical
Co .,LTD . . Kawauchi,Tokushima 771-01 Japan .
The micronucleus (MN) and a chromosomal aberration (CA) tests were used to
study in vivo the mutagenicity of polyploid inducers in mouse bone marrow cells .
Five chemicals, e .g . ethyl vanillin, narcotine, p-nitrotoluene,
diethylstilbestrol, thiabendazole, were used as specific in vitro polyploid
inducers (1) . These chemicals were suspended in olive oil and were injected
intraperitoneally to BDF1 male mice (8 veek-old, 23 .2-28 .5g) . In pilot PQN-test,
frequencies of micronucleated polychromatic erythrocyte (MNPCEs) varied from 0
to 0 .4% depending on the dose and sampling time . The main test was carried out
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
1989 EMS Abstracts 63
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