Registration Dossier

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: OECD guideline used.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
GLP compliance:
yes
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Aldrich Chemical; purified by recrystalization; purity 99.8% (with moisture 1.03%)

Test animals

Species:
mouse
Strain:
C57BL
Sex:
male/female

Administration / exposure

Route of administration:
oral: unspecified
Vehicle:
Corn oil
Duration of treatment / exposure:
single dose; Smears were prepared at 24, 48 and 72 hrs after dosing.
Doses / concentrations
Remarks:
Doses / Concentrations:
3125 and 5000 mg/kg
Basis:
actual ingested
No. of animals per sex per dose:
1st experiment: 5 animals per dose per sacrifice date
2nd experiment: 15 males per dose (24 h sacrifice)
Control animals:
yes, concurrent vehicle
Positive control(s):
cyclophosphamide

Examinations

Tissues and cell types examined:
Bone marrow smears were prepared at 24, 48 and 72 hours after dosing.
Details of tissue and slide preparation:
The preparations were stained with polychrome methylene blue and eosin. 1000 Polychromatic erythrocytes per slide were evaluated for the
presence of micronuclei. Approximately 1000 erythrocytes were counted to obtain the cytotoxicity.

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls validity:
valid
Negative controls validity:
not specified
Positive controls validity:
valid

Any other information on results incl. tables

LETHALITY
No mortality on each 5 male and 5 female mice was observed
till 4 days after 5000 mg/kg single dose.

MEAN INCIDENCE OF MICLONUCLEI/1000 CELLS
based on 5 observations:
   chemical          dose      sex     24hr   48hr   72hr
------------------------------------------------------------
-negative control   20mL/kg    male    0.8     1.4    0.8
                    20mL/kg   female   1.4    0.4    0.6
positive control    65mg/kg   male    17.0**
                    65mg/kg  female    13.6**
test substance    3125mg/kg   male      2.6*
                  3125mg/kg  female    1.0
                  5000mg/kg   male      3.2*   2.8    1.4
                  5000mg/kg  female    1.2    0.8    1.2
------------------------------------------------------------
-*  significant increase (p<0.05)
** significant increase (p<0.01)
negative control = corn oil
positive control = Cyclophosphamide
Positive control gave the expected increase in the frequency of micronucleated polychromatic erythrocytes (MPE).
As a slight increase was observed in above (*), below confirmation experiment was executed.

based on 15 observations (confirmation experiment in male):
   chemical          dose     sex     24hr
------------------------------------------------------------
-negative control   20mL/kg   male     2.5
test substance    3125mg/kg   male     2.0
                 5000mg/kg   male     4.2
------------------------------------------------------------
-negative control = corn oil
No significant statistic increase was observed in male.

MEAN PERCENTAGE OF POLYCHROMATIC ERYTHROCYTES
based on 5 observations:
   chemical          dose     sex      24hr   48hr   72hr
------------------------------------------------------------
-negative control   20mL/kg   male    30.0   35.4   36.2
                    20mL/kg  female  32.0   36.8   39.2
positive control    65mg/kg   male    30.7
                    65mg/kg  female   30.8
test substance   3125mg/kg  male    38.1
                  3125mg/kg  female  34.9
                  5000mg/kg   male    16.2*  28.0   34.1
                  5000mg/kg  female  23.1   29.7   29.7
------------------------------------------------------------
-*  significant decrease (p<0.05, means slight cytotoxicity)
negative control = corn oil
positive control = Cyclophosphamide

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
The data obtained indicate that this substance is not clastogenic in the mouse micronucleus test.