Environmental and Molecular Mutagenesis - Legacy Tobacco ...

466
I)ISCRE:TE PRODADILITY MODELS IN MAMMALIAN MUTAGENESIS
I~ .Ilamnanth fvra.~ DeparlrqpeFt of Genetics . Osmania University,
Ilyderabad - 500 007 (A .P .) India .
One of the objectives of genetic toxicology is to critically evaluate the
mutagenicity of various industrial chemicals and environmental pollutants using
dominant lethal system in mice . T he statistical problem arising out of such
situations is to Identify the probability distribution of the variables underconsideration
to assess the significance of the lethality . Preliminary distributions
like binomial, and poissori have beeft' suggested by Haseman and Soares (1976)
for the distribution of lethality in plants and mice and are currently in vogue .
However, these distributions have been found to be inadequate . The complexity
of the biological phenomenon envisages the possible role of the com pound
probability distributions . Based on series of experiments conducted in our
laboratory on dominant lethals in mice a new discrete compound probability model
has been constructed . The study suggests that the model fits well for evaluating
even weaker mutagens thus making it appropriate for wider application in the
field of environmental mutagonesis .
467
PREVENTION OF GENETIC DANAGE INDUCED BY BENZO(a)PYRENE IN NICE BY PROSTAGLANDINS
K .P .Rao, K .Sridevi, and K .V .Chandrika, Department of Genetics, Osmania University,
Hyderabad-500007, INDIA .
The present investigation is undertaken to see the possible antimutagenic action of
Prostaglandin E1(PGE1) against Benzo(a)pyrene (BP) induced genetic damage in bone marrow
cells of mice by micronucleus test . Recent investigations revealed that certain
mutagens/carcinogens are known to influence the production of PGs and thus suggesting that
an altered PG system could be responsible for mutation and cancer . Hence, two experiments
using micronucleus test in bone marrow cells of mic$ were ~arried out . In the first
experiment the effect of different doses of P~El (10- to 10- N) on BP induced genetic
damage was studied . The effect of PGE1 (10- M) in relation to cell cycle against BP
induced genetic damage was studied in the second experiment . The results obtained from the
above studies substantiates the possible role of PGa in the pathogenesis of mutagenesis and
carcinogenesis .
468
M1p1/LATIeN OF RADIATIGN-IMJ11C® GEMETIC DAMIIGE BY 2-0EO7fY-0-GLlIC06E IN TISSIR :S OF TRIGD)ELLA FOE
K.V.S . RAO. G . Jayaraman and P .M . Gopinath . Department of Genetics . PGIBMS. llniwrsity of Madras, Tara .ani,
Madras - 600 113 . India . Modulatory effect of 2-deoxy-D-Olucwe (2-OG) on radiation induced genetic
damage has been assessed in the cells-of fenu0reek . Trioonells foenua-oraeoue . 2-DG . a Oluoose antioete-
bolite and an inhibitor of glycolysis was reported to exert differential action in irradiated normal and
neoplastic mammalian cells . Mhile I,t potentiates radiation induced genetic damage in tumor cells . !t
reduces siailer damage in noraal cells . In t1a present study roots of fenu0reek were lrradiatW with
ganee rays and post-treated with 2-nG . Cytological preparations obtained from the roots on recovery were
scored to record aitotic indices . instances of ∎icronuclei and ∎itotic anomalies . Roots and calli were
cultured in aediua containing 2-DG to record data on growth kinetics . DNA extracted from these tissues
was irradiated both In the presence and absence of 2-DG and subjected to spectrophotoaetric characterization
. For corroborative date . DNA from calf thyaus and Salaonella tvohieuriua was employed . 2-DG was
found to reduce the incidence of radiation induced ∎icronuclei snd mitotic anoealies !n seedling snd
cultured roots . Reduction of mitotic activity by 2-DG was significant . 2-DG Inhibited proliferation of
cultured tissues . Spectrophotometric characterization of Irradisted DNA in the presence/absence of 2-DG
reveals no direct interaction with DNA in v tr . DNA of calf thymus and ;; . tv6hiaurium also exhibited
similar observations . From the observations It is concluded that 2-DG causes reduction !n radiation-
induced genetic damage also in plant cells . 2-DG is found to be a eitotic inhibitor and reduces the growth
of celli and cultured excised roots . 2-DG did not show direct Interaction with DNA,lrn vitro .
A
1989 EMS Abstracts 161
Notes
469 hEOSEMOGENIC RI83C PREDICTION OF TFE CYTOBTATIC TREIT!'lEliT
Tibor Raposa ?i .D ., and Judith Yirkonyi, n .D . Setttmelweis Univ . Ned .
6chool,Ill . bept .of Internal riedicine, 1121 .~udapest,EBtv6s u. 12 .Eung .
The genotoxicity of wide range of cytostatice, commonly used in the
therapy of lymphonas and solid tumors wae measured in the " in vivo -
in vitro " SCE assay . A comparison was them made to analyse the rela- r
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