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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
Type of information:
experimental study
Adequacy of study:
key study
Study period:
15 March 1988 to 08 April 1988
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study

Data source

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

Materials and methods

Test guidelineopen allclose all
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Deviations:
no
Qualifier:
according to
Guideline:
other: EPA Health Effect T G, EPA Report 560/6-83-001
GLP compliance:
yes
Type of assay:
other: micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid
Details on test material:
Name of test material (as cited in study report): Organofunctional Silane A-1120; 1,2-EthenediamineN-[3-(trimethoxysilyl)propyl]-
- Substance type: Monoconstituent
- Physical state: Liquid
- Impurities (identity and concentrations): chloride 0.6; iron 4.9ppm, cyclics and trans 0.08; Bis A-1120 6.65
- Purity test date: Not known
- Lot/batch No.: 0332RC101887
- Stability under test conditions: In corn oil for months
- Storage condition of test material: room temperature

Test animals

Species:
mouse
Strain:
Swiss Webster
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Laboratories, Portage, MI
- Age at study initiation: 5 weeks
- Weight at study initiation: male - 22.5 g - 28.0 g. female - 19.8 g - 21.7 g
- Assigned to test groups randomly: randomised separately by sex
- Fasting period before study: no
- Housing: 5 mice/sex/cage in shoe-box type plastic cages
- Diet: Agway Prolab animal diet (rat/mouse/hamster 3000), Agway Inc. (NY, USA), ad libitum
- Water: ad libitum


ENVIRONMENTAL CONDITIONS
- Temperature (°C): controlled but not specified
- Humidity (%): controlled but not specified
- Air changes (per hr): not known
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
intraperitoneal
Vehicle:
- Vehicle(s)/solvent(s) used: corn oil
- Justification for choice of solvent/vehicle: incompatible with water thus corn oil was used
- Concentration of test material in vehicle: 200 mg/kg
Duration of treatment / exposure:
single intraperitoneal dose
Frequency of treatment:
single treatment only
Post exposure period:
30, 48 and 72 hours
Doses / concentrationsopen allclose all
Dose / conc.:
87.5 mg/kg bw/day (actual dose received)
Dose / conc.:
175 mg/kg bw/day (actual dose received)
Dose / conc.:
280 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
5
Control animals:
yes
Positive control(s):
Triethylenemelamine
- Justification for choice of positive control: known to demonstrate the sensitivity and responsiveness of the animals in the definitive test.
- Route of administration: intraperitoneal
- Doses/concentrations: 0.3 mg/kg bw

Examinations

Tissues and cell types examined:
Blood was collected by nicking the tail of each animal with a scalpel and slides prepared for each animal per sampling time. Polychromatic erythrocytes (PCE's) were examined.
Details of tissue and slide preparation:
CRITERIA FOR DOSE SELECTION: Determination of the PCE/NCE ratio for the groups of animals with partial mortality was used to evaluate the possibility of bone marrow cytotoxicity from the test chemical. Three dose levels of approximately 80%, 50% and 25% of the LD50 value were evaluated for effects upon the incidence of micronuclei.

TREATMENT AND SAMPLING TIMES (in addition to information in specific fields): i.p. injection followed by sampling times of 30, 48 and 72 hours

DETAILS OF SLIDE PREPARATION: Slides were stained with Gurr's R-66 Giemsa diluted in phosphate buffer. Slides were coded by animal number only and read blindly.

METHOD OF ANALYSIS: A minimum of 1000 PCE's were examined microscopically for each animal per sample time. The PCE/NCE ratio for approximately 1000 total cells was calculated and recorded. The number of micronucleated PCE/1000 NCE was recorded.

Evaluation criteria:
A test result is considered to be negative if no statistically significant or dose related increases are apparent between the vehicle control and groups of animals treated with Organofunctional Silane A-1120.
Statistics:
Fisher's Exact Test (Sokal and Rohlf, 1981)

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
yes
Remarks:
LD50 354 mg/kg bw and above. PCE/NCE ratio was reduced at highest concentration, 48 h exposure and at all doses, 72 h exposure.
Vehicle controls validity:
valid
Negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
RESULTS OF RANGE-FINDING STUDY
- Dose range: 125 mg/kg bw - 2000 mg/kg b
- Solubility: Incompatible with water thus corn oil was used
- Clinical signs of toxicity in test animals: All mice dosed at 1000 mg/kg bw and 2000 mg/kg bw died. 500 mg/kg bw was lethal to 4 out of 5 females and all the male mice. One female tested at 250 mg/kg bw died.
- Evidence of cytotoxicity in tissue analyzed: a decrease in the PCE/NCE ratio to 80% of the control value was observed at the 48 hour treatment interval. At 72 hours the PCE/NCE ratios had increased.
- Harvest times: 48 and 72 hours


RESULTS OF DEFINITIVE STUDY

- Induction of micronuclei (for Micronucleus assay): negative.
- Ratio of PCE/NCE (for Micronucleus assay): PCE/NCE ratio was slightly decreased at 72 hour treatment interval.
- Appropriateness of dose levels and route: Both dose levels and route were appropriate.
- Statistical evaluation: Analysis of variance indicated no sex-related differences in the incidence of micronuclei. No statistically significant (p ≤ 0.01) or treatment related increases in the numbers of micronuclei were observed at any dose or treatment interval.

Any other information on results incl. tables

Table 2: Summary of micronucleus results.

 

30 hours

48 hours

72 hours

Treatment groups mg/kg

Number of PCE’s with micronuclei per 1000 PCE’s

Mean PCE’s/1000 NCE (SD)

Number of PCE’s with micronuclei per 1000 PCE’s

Mean PCE’s/1000 NCE (SD)

Number of PCE’s with micronuclei per 1000 PCE’s

Mean PCE’s/1000 NCE (SD)

Male

Female

Group mean

SD

Male

Female

Group mean

SD

Male

Female

Group mean

SD

Vehicle control

4.0 (2.00)

1.6 (0.89)

33.7

5.52

2.4 (2.70)

3.6 (1.14)

36.4

4.24

3.8 (2.05)

3.8 (2.68)

42.9

3.25

87.5

5.0 (2.55)

3.6 (1.52)

31.8

6.79

3.0 (1.73)

2.2 (0.84)

36.0

0.28

6.4 (2.19)

2.8 (1.64)

33.9

2.12

175

2.6 (1.52)

4.0 (1.22)

34.9

8.06

3.2 (1.10)

3.8 (1.64)

37.2

7.92

2.3 (0.96)

5.2 (3.96)

35.5

6.68

280

3.4 (2.19)

3.6 (2.19)

35.4

4.81

3.4 (3.29)

3.0 (1.22)

30.4

3.39

3.8 (1.92)

1.2 (0.84)

27.9

1.27

Positive control

36.2 (16.84)

28.6 (10.31)

27.4

9.05

Not evaluated

Not evaluated

Not evaluated

Not evaluated

Table 3: Summary of micronucleus frequency and statistical differences from controls (Fisher's exact test, one-tailed).

Treatment/dose mg/kg bw

No. PCE observed

PCE with micronuclei

Statistical significance

 

30 hour sample

Vehicle control

10 000

28

NS

87.5

10 000

43

0.05>p>0.001*

175

10 000

33

NS

280

10 000

35

NS

Positive control

10 000

324

p<0.001

 

48 hour sample

Vehicle control

10 000

30

NS

87.5

10 000

26

NS

175

10 000

35

NS

280

10 000

32

NS

 

 72 hour sample

 

Vehicle control

10 000

38

NS

87.5

10 000

46

NS

175

10 000

35

NS

280

10 000

25

NS

Results from sexes are combined as no sex-related differences were shown.

* not considered of biological significance

Applicant's summary and conclusion

Conclusions:
Interpretation of results: negative
N-(3-(trimethoxysilyl)propyl)ethylenediamine has been tested in a reliable study according to EPA Health Effect T G, Report 560/6-83-001, which is similar to OECD 474, and under GLP conditions. No treatment related increases in numbers of micronuclei in PCE's of Swiss-Webster mice were observed. Relatively high dose levels of the test compound were tested up to 80% of the LD50 with no indication of significant induction of micronuclei. The PCE/NCE ratio was reduced at the highest concentration, 48 h exposure and at all doses, 72 h exposure, indicating exposure of the target tissue to the test substance. The test compound is considered to be negative for the induction of micronuclei under the conditions of this test.