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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993
Report date:
1993

Materials and methods

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

Test material

Constituent 1
Chemical structure
Reference substance name:
2-(dimethylamino)ethyl acrylate
EC Number:
219-460-0
EC Name:
2-(dimethylamino)ethyl acrylate
Cas Number:
2439-35-2
Molecular formula:
C7H13NO2
IUPAC Name:
2-(dimethylamino)ethyl acrylate
Details on test material:
- Name of test material (as cited in study report): Dimethylaminoethyl acrylate (ADAME)
- Purity: 99.87%
- Physical state: yellowish liquid
- Supplier: Elf Atochem
- Lot No.: RN 108
- Storage condition of test material: 4°C in the dark

Test animals

Species:
mouse
Strain:
Swiss
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ORGANISMS:
- Strain: Swiss OF1/CO: OF1(IOPS Caw)
- Source: Iffa Crédo (69210 L'Arbresle, France)
- Age: approx. 6 weeks
- Weight at study initiation: mean males 30-36 g, mean females 24-29 g
- Housing: 5 mice of same sex and group per cage in polycarbonate cages (33.5 x 18.7 x 13.0 cm)
- Diet: A04 C pelleted diet (U.A.R., 91360 Villemoisson-sur-Orge, France) ad libitum
- Water: filtered tap water ad libitum
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21±2
- Humidity (%): 50±20
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:
intraperitoneal
Vehicle:
- Vehicle: physiological solution of 0.9% NaCl
Details on exposure:
- Administration volume: 10 ml/kg
- Sampling times: all animals 24 hours and 48 hours after the 2nd administration
Duration of treatment / exposure:
48 hours
Frequency of treatment:
twice separated by 24 hours
Doses / concentrations
Remarks:
Doses / Concentrations:
75 mg/kg bw
Basis:

No. of animals per sex per dose:
2 groups, each comprising 5 males and 5 females and one additional group composed of 3 males and 3 females.
Control animals:
yes, concurrent vehicle
Positive control(s):
25 mg/kg Cyclophosphamide (2 administrations separated by 24 hours)

Examinations

Tissues and cell types examined:
- Analysis of bone marrow smears: For each animal, the micronuclei were counted in 2000 polychromatic erythrocytes; the polychromatic (PE)/normochromatic (NE) erythrocyte ratio was established by scoring a total of 1000 erythrocytes (PE+NE ). At each sampling time, the mean number of micronucleated polychromatic erythrocytes (MPE) and the PE/NE ratio given for each animal of the treated groups, are compared to the simultaneous vehicle groups.
Evaluation criteria:
The results were considered positive if:
- A statistical significant increase in the number of MPE for at least one of the sampling time is recorded when compared to the vehicle groups.
-This increase should double the number of MPE of the laboratory historical data.
Statistics:
X² test for MPE; student's t test for PE/NE ratio

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
yes
Remarks:
24 hours after the 2nd administration, the PE/NE ratio decreased significantly (p < 0.001) from that of the vehicle control groups. 48 hours after the 2nd administration, the ratio had decreased but not significantly.
Vehicle controls validity:
valid
Positive controls validity:
valid
Additional information on results:
MORTALITY: 2 animals were found dead 48 hours after the 2nd injection, 2 of the supplementary animals replaced those which died.

CLINICAL SIGNS: Piloerection and hypokinesia were observed.

GENOTOXIC EFFECTS: In all groupstreated with the TS the mean value of micronucleated polychromatic erythrocytes were similar to those of their respective vehicle groups at each sampling time, and no statistical significant differences weres observed. Moreover, 24 hours after the 2nd administration, the PE/NE ratio decreased significantly (p<0.001) from that of the respective vehicle control groups, showing the toxic effect of the TS to bone marrow cells. 48 hours after the 2nd administration, the ratio had decreased but not statistically significantly due to the fact that the ratio of one female was high compared to the ratios of the other animals, despite the poor number of PE scorable.

Any other information on results incl. tables

Results of the Micronucleus Test:

Time of sacrifice: 24 hours after the 2nd administration

Group

Dose

(mg/kg)

MPE per 1000 PE

PE/NE ratio

Mean

SD

Mean

SD

Vehicle

-

2.0

0.8

0.7

0.2

ADAME

75

1.5

1.1

0.3***

0.1

CPA

25

18.2***

3.8

0.4***

0.1

 

Time of sacrifice: 48 hours after the 2nd administration

Group

Dose

(mg/kg)

MPE per 1000 PE

PE/NE ratio

Mean

SD

Mean

SD

Vehicle

-

1.9

0.8

0.9

0.4

ADAME

75

1.3

0.9

0.5

0.5

*** = p<0.001; ADAME = 2-(dimethylamino)ethyl acrylate, CPA = cyclophosphamide, PE = polychromatic erythrocytes, NE = normochromatic erythrocytes, MPE = micronucleated polychromatic erythrocytes, SD = standard deviation.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
Under the experimental conditions used, the test substance did not induce cytogenetic damage to the bone marrow cells of mice when treated twice separeted by 24 hours by intraperitoneal route at 75 mg/kg in the micronucleus test.
Executive summary:

The study is reliable without restrictions (GLP guideline study according to OECD: Micronucleus test in mice).

The mice of the treated groups (2 groups, each comprising 5 males and 5 females and one additional group composed of 3 males and 3 females) received 2 intraperitoneal administrations of the TS at 75 mg/kg separated by 24 hours using a dose volume of 10 ml/kg. The animals of the vehicle control groups (2 groups, each comprising 5 males and 5 females) received 2 intraperitoneal administrations of a physiological solution separated by 24 hours. The animals of the positive control group (5 males and 5 females) received 2 intraperitoneal administrations of cyclophosphamide at 25 mg/kg separated by 24 hours. The animals of the treated and vehicle control groups were sacrificed 24 and 48 hours after the 2nd treatment and the animals of the positive control group were sacrificed 24 hours after the 2nd treatment. Bone marrow smears were prepared. For each animal, the micronuclei were counted in 2000 polychromatic erythrocytes. The polychromatic (PE) and normochromatic (NE) erythrocyte ratio was established by scoring a total of 1000 erythrocytes (PE + NE).

In the two vehicle control groups, the mean values of micronucleated polychromatic erythrocytes (MPE) were within the range of historical data. Cyclophosphamide induced a highly significant increase (p< 0.001) in the number of MPE, indicating the sensitivity of the test system under the experimental conditions chosen. In addition, the PE/NE ratio decreased significantly (p<0.001) showing the toxic effect of this substance to bone marrow cells. In all groups treated with the TS, the mean values of micronucleated polychromatic erythrocytes were similar to those of their respective vehicle groups at each sampling time, and no statistically significant differences were observed. Moreover, 24 hours after the 2nd administration, the PE/NE ratio decreased significantly (p<0.001) from that of the respective vehicle control groups, showing the toxic effect of the test substance to bone marrow cells. Forty-eight hours after the 2nd administration, the ratio had decreased but not significantly.

Conclusion: The TS did not induce cytogenetic damage to the bone marrow cells of mice when treated twice separated by 24 hours by

intraperitoneal route at 75 mg/kg in the micronucleus test.

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