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Toxicological information

Genetic toxicity: in vivo

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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
Study period:
May - August 1985
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study was not performed according to guideline, but meets the principles of OECD guideline 474 with the following restriction: only 1000 immature erythrocytes per animal were counted.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1986
Report date:
1986

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Deviations:
not applicable
GLP compliance:
no
Remarks:
but GLP like quality assurance
Type of assay:
micronucleus assay

Test material

Constituent 1
Chemical structure
Reference substance name:
1-(N,N-bis(2-ethylhexyl)aminomethyl)-1,2,4-triazole
EC Number:
401-280-0
EC Name:
1-(N,N-bis(2-ethylhexyl)aminomethyl)-1,2,4-triazole
Cas Number:
91273-04-0
Molecular formula:
C19 H38 N4
IUPAC Name:
1-(N,N-bis(2-ethylhexyl)aminomethyl)-1,2,4-triazole
Details on test material:
- Analytical purity: Commercial grade

Test animals

Species:
hamster, Chinese
Strain:
other: random outbred strain
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: CIBA-GEIGY Tierfarm, Sisseln.
- Age at study initiation: female 6-10 weeks, male 4-9 weeks
- Weight at study initiation: female 21-32 g, male 21-38 g (tolerability test), female 20-31 g, male 21-34 g (mutagenicity test)
- Water: ad libitum
- Diet: standard diet, NAFAG No.924

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22-23°C
- Humidity (%): 46-50%
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
Vehicle used: aqueous solution of sodium carboxymethylcellulose (0.5%)
Details on exposure:
PREPARATION OF DOSING SOLUTIONS: 5000 mg/kg test item in 20 mL/kg 0.5% aqueous solution of sodium carboxymethylcellulose.
Frequency of treatment:
Single application
Post exposure period:
16, 24 and 48h after application
Doses / concentrations
Remarks:
Doses / Concentrations:
5000 mg/kg
Basis:
actual ingested
No. of animals per sex per dose:
In the tolerability test: 2 males and 2 females
In the mutagenicity test: 24 males and 24 females each in the treatment group and in the negative control group (8 males and 8 females per sampling time).
8 males and 8 females in the positive control group.
Control animals:
yes, concurrent vehicle
Positive control(s):
cyclophosphamide (64 mg/kg)

Examinations

Tissues and cell types examined:
Bone marrow; erythrocytes
Details of tissue and slide preparation:
SAMPLING TIME: 16, 24 and 48 h after application

DETAILS OF SLIDE PREPARATION: Bone marrow was harvested from the shafts of both femurs. In a siliconized pipette filled with approx. 0.5 µL rat serum the bone marrow was drawn up. Small drops of the mixture were transferred on the end of a slide, spread out by pulling it behind a polished cover glass and the preparations were air-dried. Three hours later, the slides were stained in undiluted May-Grünwald solution for 2 min then in May-Grünwald solution/water 1/1 and then in Giemsa's, 40% .

METHOD OF ANALYSIS:1000 polychromatic erythrocytes each were scored for the incidence of micronuclei per animal. The ratio of polychromatic to normochromatic erythrocytes was determined for each animal by counting a total of 1000 erythrocytes.
Statistics:
The significance of difference was assessed by X2-test.

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls validity:
valid
Negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
RESULTS OF RANGE-FINDING STUDY
- Dose range: 5000 mg/kg bw
- Mortality: none

RESULTS OF DEFINITIVE STUDY
- Induction of micronuclei: The bone marrow smears from animals treated with the dose of 5000 mg/kg of the test item showed no statistically significant increase (p>0,05) in the number of micronucleated polychromatic erythrocytes compared to the negative control animals at all three sampling times.
- Ratio of PCE/NCE: Ratio was not influenced by the test item.
- The respective "positive control" experiments with cyclophosphamide (64 mg/kg) yielded an average of 4.15% polychromatic erythrocytes with micronuclei. This is significantly different from the controls (0.15%) treated with the vehicle (0.5% CMC) alone.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
Under the conditions of this experiment, no evidence of mutagenic effects was obtained in Chinese hamsters treated with the test substance.
Executive summary:

A micronucleus experiment was performed to evaluate any mutagenic effect of the test article on polychromatic erythrocytes in bone marrow cells in vivo. The test article in 0.5% carboxymethyl cellulose was administered orally to groups of 24 female and 24 male animals each in the negative and in the 5000 mg/kg dose group. The positive control group consisted of 8 female and 8 male animals and was treated with Cyclophosphamide (64 mg/kg). Treatment consisted of a single application. 16, 24 and 48h after application 8 female and 8 male animals per group and sampling time were sacrificed by dislocation of the cervical vertebrae. From the bone marrow smears were made. The bone marrow smears from animals treated with the dose of 5000 mg/kg showed no statistically significant increase (p>0,05) in the number of micronucleated polychromatic erythrocytes compared to the negative control animals at all three sampling times. The respective "positive control" experiments with cyclophosphamide yielded an average of 4.15% polychromaticerythrocytes with micronuclei. This is significantly different from the controls (0.15%) treated with the vehicle (0.5% CMC) alone. It is concluded that under the conditions of this experiment, no evidence of mutagenic effects was obtained in Chinese hamsters treated with the test substance.