Environmental and Molecular Mutagenesis - Legacy Tobacco ...

mutagenesis by DMN increasaaLwith S-9 level . 3-MCA muta9enesis reflected a 2AAF-like kinetic at low
exposure, but gave results reminiscent of DMN at higher exposure levels . Mutation frequencies (X10s)
varied as follows :
~1 u~I/mIS-9 ~uI/m IS•9
DMN (400 ug/ma) - 2i~ iT~
2AAF (40 uy7ml) S07 26S
3MCA (10 ul/ml) 280 358
(0 .625 ut/ml) 144 61
Control (Average) 51 .54
The data presented here support ou r choice of 20-40 ul S-9/ml for a 4 hr . treatment of L5178Vi cells in this
assay. However, the response of 2 AAF and the biphasic response of 3•MCA is an indication of the care
needed in choosing the optimum en zyme (S-9) concentration for routine or mechanistic investigations .
589
MUTAGENICITY AND COMUTAGENICITY STUDIES ON THREE NOOTROPII+St
PIRACETAM, ANIRACETAM AND HUPERZIIQ A . Z .H . Tu, Y .Y . Wang and W .D .
Tang . Institute of Materia Medica, Academia Sinica,Shanghai, China .
The mutagenicity and comutagenicity of 3 nootropils, piracetam,
aniracetam and hupersin A, were determined at vrious concentration
using S t himurium as the tester stains . The plate-incorporation
essay wea con uc e both in the absence and presence of an aroolorinduced
rat-liver S9 mix . A 30-min preinoubation teat protocol waa
used for experiments with Sq . None of them is mutagenic towara theae
tester stains without or with S9 . All of three drugs did not increased
the revertants incueed by p-nitroquinoline in TA98 and by MINS
in TA100. Aniracetam at 2 .5 mg/plate decreased the mutagen-indueed
revertans in TA98, it might be of the toxicity of aniraoetam .
Aniracetam at bigher concentration exhibited an inhibition effect
on S t himurium . The micronuoleus teata of 3 nootropile were
con3uc~3n 3ux mice at the dosage from 1/8 to 1/2 LD50 . All of
them did not effect on the frequency of micronucleated polychromatic
erythrocytes .
590
KINETOCHORES IN MICRONUCLEI: DEVELOPMENT OF A.SIMPLE AND RAPID METHOD TO
IDENTIFY EXPOSURE TO ANEUPLOIDY-INDUCING AGENTS . J .D. Tucker and D.A . Eastmond .
Biomedical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA 94550 .
The identification of agents causing aneuploidy in mammalian cells is currently limited due to
the labor intensive nature of traditional cytogenetic analyses . We have developed a new and simple
method to identify exposure to aneuploidy-inducing agents (aneuploidogens) . The assay involves the
induction of micronuclei in cytokinesis-blocked cells and the use of an antibody with a specificity of
> 99% for kinetochore regions . Micronuclei with one or more ceneromeres are indicat)ve of cells with
a high potentia) for aneuploidy. Staining of the kinetochores is achleved with the use of a
fluorescein-conjugated seeond antibody and the nuclei are atained with DAPL With the simultaneous
use of phase contrast and DAPI excitation, it waa possible to ldentify both the cell membrane and the
nuclei while scoring . Cella with mlcronuclei were txamined for the presence of fluorescein label to
determine whether the m)cronuclens contained a kinetochore. Every agent tested produced a doserelated
Increase in the frequency of micronucleattd cells . In human peripheral lymphocytes, the
micronucleated cella indueed by the aneuplo)dogens eolehicine, vlncrlatine sulfate and
diethylstilbestrol contafned kinetochore-positive m)cronuclef 92%, 87%, and 76% of the time,
respectively. In contrast, the micronucleated celis induced by the potent clastogens Ionizing radiation
and sodium arsenite contained kinetochore-positive micronucfe) only 3% and 19% of thq time,
respectively. In Chinese hamster ovary cells, the micronncleated cells induced by the aneuploidogena
benomyl and vinblastine sulfate contained kinetochore-positive miuonuclti 92% and 94% o£ the
time, respectively . With methyl methanesulfonate, however, only 11% contained a kinetochore .
These results indicate that this simple and ra id procedure can discriminate between aneuploidogens
and clastogens, and may allow mort rap)d identillcation of exposure to aneuploidogens both in vitro
and in vivo. Work performed under the auspices of the U.S . DOE by Lawrence Livermore National
Laboratory under contract No . 7405-ENG-48, with additional support from the Alexander Hollaender
Distinguished Postdoctoral Fellowship (D .A.E .) .
591
SMOKE EXPOSURE, AGE, SEX, RACE, AND POTENTIATION AS VARIABLES AFFECTING SISTER
CHROMATID EXCHANGE INDUCTION IN NUMANS . D .A . Tulis, J .K . Smollinger, and W .H .
McKenzie, North Carolina State University, Raleigh, NC (USA) .
In vitro cytogenetic analysis was performed on peripheral lymphocytes of 49
passively smoking children, ages 6 mo to 5 yrs . Mean SCE for non-smokers (7 .60 i 0 .46)
was not significantly different (p > 0 .746) from mean SCE for passive smokers (7 .85 3
0 .39) . However, passively smoking children demonstrated a highly significant
(p < 0 .001) SCE increase to in vitro a-naphthoflavone (ANF) exposure, while the nonsmoking
children showed a much lower but etill significant SCE increase to in vitro
ANF exposure (p < 0 .03) . These results suggest that ANF has the potential to magnify
and therefore detect an SCE insult experienced by passively smoking children . Age,
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
1989 EMS Abstracts 203
Notes
r