Registration Dossier

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant guideline study, available as published report, minor restrictions in design and/or reporting but otherwise adequate for assessment

Data source

Reference
Reference Type:
secondary source
Title:
4-Aminotoluene-3-sulfonic acid CAS: 88-44-8, SIDS Initial Assessment Report For SIAM 16
Year:
2003
Bibliographic source:
As cited in: SIDS Initial Assessment Report For SIAM 16, UNEP PUBLICATIONS
Report Date:
2003

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:
- Name of test material (as cited in study report): 4-Aminotoluene-3-sulfonic acid
Other TS: Aldrich Chemical;
purified by recrystalization;
purity 99.8% (with moisture 1.03%)

Test animals

Species:
mouse
Strain:
C57BL
Sex:
male/female
Details on test animals and environmental conditions:
TEST ORGANISMS and HUSBANDRY
- strain: male and female C57BL/6JfCD-1/Alpk mice
- age: 13-14 weeks for lethality, 8-12 weeks for micronucleus test
- food: Porton Combined Diet
- water: filtered tap water

ENVIRONMENTAL CONDITIONS
- room temperature: 17-26°C
- humidity: 48-75%
- lighting: 12hr light/dark cycle
- air: 15 air change per hour

Administration / exposure

Route of administration:
oral: unspecified
Details on exposure:
single dose by oral route (probably by gavage), at 5000 and 3125 mg/kg and the controls
Duration of treatment / exposure:
single dose
Frequency of treatment:
only once
Post exposure period:
up to 72 hour
Doses / concentrations
Remarks:
Doses / Concentrations:
3125, 5000 mg/kg
Basis:
no data
No. of animals per sex per dose:
Each 5 for lethality, each 5 per kill-time per dose for micronucleus test
Control animals:
other:
Positive control(s):
Positive control: Cyclophosphamide, 65 mg/kg

Examinations

Tissues and cell types examined:
Bone marrow smears:
- incidence of micronuclei/1000 cells;
- percentage of Polychromatic erythrocytes.
Details of tissue and slide preparation:
Bone marrow smears were prepared at 24, 48 and 72 hours after dosing. 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.
Evaluation criteria:
Not specified
Statistics:
No data

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
yes
Remarks:
slight cytotoxicity at 24 hr in male test group treated with 5000 mg/kg test substance.
Vehicle controls valid:
not specified
Negative controls valid:
not specified
Positive controls valid:
yes
Additional information on results:
No mortality on each 5 male and 5 female mice was observed till 4 days after 5000 mg/kg single dose.
Though slight cytotoxicity was observed on polychromatic erythrocytes at 5000 mg/kg in males, it did not show a statistically significant increase on the ratio of micronucleated polychromatic erythrocytes at extended count. Therefore, the result of the micronucleus assay was negative.
The data obtained indicate that 4-Aminotoluene-3-sulfonic acid is not clastogenic in the mouse micronucleus test.

Any other information on results incl. tables

MEAN INCIDENCE OF MICRONUCLEI/1000 CELLS

based on 5 observations:

Chemical

Dose

Sex

24 hr

48 hr

72 hr

Negative control

20 mL/kg

Male

0.8

1.4

0.8

 

20 mL/kg

Female

1.4

0.4

0.6

Positive control

65 mg/kg

Male

17.0**

 

 

 

65 mg/kg

Female

13.6**

 

 

Test substance

3125 mg/kg

Male

2.6*

 

 

 

3125 mg/kg

Female

1.0

 

 

 

5000 mg/kg

Male

3.2*

2.8

1.4

 

5000 mg/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

24 hr

Negative control

20 mL/kg

Male

2.5

Test substance

3125 mg/kg

Male

2.0

 

5000 mg/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

24 hr

48 hr

72 hr

Negative control

20 mL/kg

Male

30.0

35.4

36.2

 

20 mL/kg

Female

32.0

36.8

39.2

Positive control

65 mg/kg

Male

30.7

 

 

 

65 mg/kg

Female

30.8

 

 

Test substance

3125 mg/kg

Male

38.1

 

 

 

3125 mg/kg

Female

34.9

 

 

 

5000 mg/kg

Male

16.2*

28.0

34.1

 

5000 mg/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