Environmental and Molecular Mutagenesis - Legacy Tobacco ...

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immaaoasuay was developed os the reaction of the antibodies witb the ovalbumia-baptem In
microtiter ptat6f .
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and 2500 pmol Me1Qx, 4,8-diMeIQz aad PhIP . No iahlbitioa was seea for 1 umol ereatiae ot
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618 OBSERVATION ON RENAL HYPERPLASIA CAUSED BY UNILATERAL NEPHRF.CIC)MY
IN MICE AND ITS SIGNIFICANCE IN SEARCH FOR ANIMAL TESTS FOR
CHEMICAL CARCINOGENS
Da Wang
(Shanghai Institute of Biochemistry, Academia Sinica)
A series of histological and anatomical changes of different stages was compared
after unilateral nephrectomy in mice between the remained kidney and the
sham-operated kidney . Results of the experiment revealed that after unilateral
nephrectomy in ICR mice a series of changes occurred in the remained kidney :
there were increase in weight, increase in thicknesses of renal cortex and
medulla, increases in size of the renal corpuscle, increases in number of cell
in the glomerulus, hyperplasia of epithelial cells in the renal tubule, dilatation
of renal blood vessels and stromal hyperplasia . Administration of chemical
carcinogens to the hypertrophic and hyperplastic kidney may aggravate
cell hyperplasia and degeneration in the remained kidney, and promote the
development of tumors . The shortening of induction period of tumors after unilateral
nephrectomy might help to supply a better model for chronic induction
of animal experiment in vivo .
619 •
MUTAGENIC AND ANTIMUTAGENIC EFFECTS OF 9-AMINOACRIDINE IN THE YEAST SACCNAROYNYCSS
CsRevISZns . Q . Wang, U .G .G . Hennig, and R .C . von Borstel, Department of Genetics,
University of Alberta, Edmonton, Alberta (Canada) T6GJE9
Certain chemicals exhibit the property of reducing the spontaneous mutation rates
in the yeast SaooharoVoee oerev{eiae . In systems for forward mutations (canavanine
sensitivity to resistance) and reversions (histidine auxotrophy to prototrophy),
9-aminoacridine was reported to be antimutagenic during mitosis (Magni et at . 1964,
!autat . Ree . 1 : 227-230 ; Pugllsi 1967, Mutat . Rea . 4 : 289-294) . Also, there appears to
be a base sequence specificity involved in the binding of 9-aminoacridine to ONA
(Young et aZ . 1980, Prod . NatZ . Acad . Soi . (USA) 77 : 6453-6457) . The effects of antimutagenic
agents can be quite different on various loci . We have found that 9-aminoacridine
has antimutagenic effects on the hom3-10 frameshift allele but not on the
hisl-7 and arg4-17 base substitution alleles in strain XV185-14C of yeast . Mutation
rate measurements were made in growinaq cells of yeast with the 1000-compartment
fluctuation test (von Borstel 1978, in Methods in Cell Biology", Vol . 20, Academic
Press, pp . 1-24) . For the hom3-10 allele, 9-aminoacridine, at concentrations of 10-20
ug/ml, increased the mutation rate 4-fold (mutagenic) and at 50-100 ug/ml it decreased
the mutation rate 2-fold (antimutagenic) . The concentration range of 50-100 ug/ml
causes a delay in cell generation time (from 1 .8 hr to 2 .7 hr), which is a decrease in
the rate of cell division . These results implicate an interaction between DNA repair
and the delay in the cell cycle in the mechanisr of antimutagenesis when chemicals are
involved . (This research was supported by a grant from the Natural Sciences and
Engineering Research Council of Canada) .
620
EFFECTS OF CHEMICAL 1eDTAGENESIS ON TREATINO ZYOOTES OF PIANTS . Wang Qinnan . Institute of
Genetics, Academia Sinioca, Beijing .
According to the theory of mosaicism, some investigators have considered that treatment
of zygotes may afford an opportunity to increase the mutation rate . Therefore we have
designed experiments to study the effect of treating zygotes with a chemical autagen .
We used wheat zygotes and dry seeds and the mutagen EMS . In addition, the wheat zygotes
were given bleomycin (BLM) post-treatment so as to enhance the induction of mutations .
The results obtained indicated that treatment of zygotes with EMS at any stage is
superior in terms of creating mutations as compared to the control . The treatment of
zygotes inducas much higher mutation ratios in the eS3 generation as compared with treating
dry seeds, and brings about a broader mutational spectrum . In accordance with the effects
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
1989 EMS Abstracts 213
Notes
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