ISSN 10227954, Russian Journal of Genetics, 2011, Vol. 47, No. 6, pp. 754–756. © Pleiades Publishing, Inc., 2011.
Original Russian Text © K.G. Ordzhonikidze, A.M. Zanadvorova, S.K. Abilev, 2011, published in Genetika, 2011, Vol. 47, No. 6, pp. 853–855.
Cytogenetic analysis of rat and mouse bone mar
row cells is currently the main experimental method
for estimating the mutagenic potential of various sub
stances in mammals. Mutagenicity is an important
prognostic characteristic of the carcinogenic activity
of chemical compounds. The estimates of genotoxic
ity of substances in different organs of mammals are
important for the prediction of carcinogenic activity.
Analysis of the database on the carcinogenic activ
ities of chemical environmental factors has shown that
the detected carcinogenic effects depend on both the
species of the experimental animals (rats or mice) and
the organ of the animals used . The organ specificity
of the genotoxic effect is currently studied using poly
organ micronucleus assay , DNA alkaline
elution assay , single cell gel electrophoresis assay
(comet assay) , and transgenic mouse assay .
They differ from one another not only in the principles
of the methods, but also in the detected genetic effects
and reliability. Polyorgan micronucleus assay is the
most reliable (valid) of them . While micronucleus
assay detects all induced micronuclei in the cells that
have completed mitosis after the exposure to a geno
toxic factor, DNA alkaline elution and comet assays
detect breaks and other DNA lesions converted into
breaks in an alkaline medium.
We studied the organ specificity of the DNAdam
aging (genotoxic) effects of the antibacterial drug
dioxidine and the antitumor drug cyclophosphamide
on mice with the use of alkaline comet assay.
The experiment was performed on male BALB/c
mice aged three to four months with a mean body
weight of 25 g kept under the standard conditions of a
vivarium. The drugs were injected once intraperito
neally. Cyclophosphamide was injected at a dose of
50 mg/kg (prepared ex tempore); dioxidine, at a dose
of 200 mg/kg (a commercial solution for injections).
The control group was administered water for injec
tions. Each group consisted of five mice. The animals
were sacrificed by cervical dislocation 5 h after the
injection. The following organs were used for the
study: the liver, lungs, spleen, and brain.
The degree of DNA damage in these organs was esti
mated as recommended in . The cells were immobi
lized in 0.5% (for brain cells, 2%) warm (
meltingpoint agarose. The resultant cell suspension was
applied onto prepared slides (1% normalmeltingpoint
agarose dissolved in water), and the cells were lysed for
(2.5 mM NaCl, 100 mM
TrisHCl, with DMSO and Triton X100 (10 and 1% of
the final volume, respectively) added on the day of the
experiment). The slides with the cell lisate layered on
them were put into an alkaline buffer solution (1 mM
mM NaOH, pH 13) for 20 min to con
Organ Specificity of the Genotoxic Effects of Cyclophosphane
and Dioxidine: An Alkaline Comet Assay Study
K. G. Ordzhonikidze
, A. M. Zanadvorova
, and S. K. Abilev
Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991 Russia
Moscow State University, Moscow, 119001 Russia
Received October 27, 2010
—The applicability of alkaline comet assay to studying the organ specificity of the genotoxic effects
of drugs has been estimated using cells from four organs of mice (the liver, lungs, spleen, and brain). It has
been found that cyclophosphamide damages DNA in all the four organs; and dioxidine, in all organs except
the brain. It is concluded that this method can be used for studying the organ specificity of the DNAdamag
ing effects of various substances.
Liver Lungs Brain Spleen
% of DNA in the comet tail Cyclophosphamide
The DNAdamaging effects of cyclophosphamide
and dioxidine in cells of some organs of mice.