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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP study/guideline study (results of TA 100 are missing in the standard plate test)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report date:
1997

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
(only 2-Aminoanthracene as positive control with S9-mix)
Qualifier:
according to guideline
Guideline:
OECD Guideline 472 (Genetic Toxicology: Escherichia coli, Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
N,N-dimethylisopropylamine
EC Number:
213-635-5
EC Name:
N,N-dimethylisopropylamine
Cas Number:
996-35-0
Molecular formula:
C5H13N
IUPAC Name:
N,N-dimethylpropan-2-amine
Details on test material:
- Name of test material (as cited in study report): N,N-Dimethylisopropylamine
- Physical state: colourless liquid
- Analytical purity: 99.8
- Lot/batch No.: tank 10
- Storage condition of test material: room temperature (N2 conditions)
- ZHT Test Substance No.: 96/134

Method

Target gene:
His- and Trp-operon
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Metabolic activation system:
The S9 fractions were prepared from the liver of Aroclor 1254-induced male Sprague-Dawley rats.
Test concentrations with justification for top dose:
standard plate test with and without S9-mix: 0; 20; 100; 500; 2500 and 5000 µg/plate.
preincubation test with and without S9-mix: 0; 4; 20; 100; 500 and 2500 µg/plate (Salmonella strains)/ 0; 20; 100; 500; 2500 and 5000 µg/plate (E. coli WP2 uvrA).
Vehicle / solvent:
- Vehicle/solvent used: water
Controls
Untreated negative controls:
yes
Remarks:
sterility control
Negative solvent / vehicle controls:
yes
Remarks:
water control
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
other: with S-9 mix: all strains 2-aminoanthracene; without S-9 mix: strains TA100, TA1535: N-methyl-N'-nitro-N-nitrosoguanidine; TA98: 4-nitro-o-phenylendiamine; TA1537: 9-aminoacridine; E.coli WP2 uvrA: N-ethyl-N'-nitro-N-nitrosoguanidine.
Details on test system and experimental conditions:
METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 min
- Exposure duration: 48 h

NUMBER OF REPLICATIONS: 3


METHOD OF APPLICATION: standard plate test

DURATION
- Exposure duration: 48 h

NUMBER OF REPLICATIONS: 3

DETERMINATION OF CYTOTOXICITY
- Method: reduction of His-positive revertants compared to control
Evaluation criteria:
The test chemical is considered positive in this assay if the following criteria are met: A dose-related and reproducible increase in the number of revertant colonies, i.e. about doubling of the spontaneous mutation rate in at least one tester strain either without S-9 mix or after adding a metabolizing system.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
bacteriotoxic effect was observed depending on the strain and test conditions at doses >= 2500 µg/plate.
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
bacteriotoxic effect was observed at doses >= 2500 µg/plate.
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Standard Plate Test

Table 1: Mean values (without S9 mix)

 

 

TA 98

TA 100

TA 1535

TA 1537

E. coli WP2 uvrA

Concentration (µg/plate)

S9

X (n=3)

revertant factor

X (n=3)

revertant factor

X (n=3)

revertant factor

X (n=3)

revertant factor

X (n=3)

revertant factor

control

minus

27

 

d.m.

d.m.

23

 

11

 

56

 

20

minus

23

0.8

d.m.

d.m.

18

0.8

9

0.8

49

0.9

100

minus

21

0.8

d.m.

d.m.

18

0.8

6

0.5

58

1.0

500

minus

22

0.8

d.m.

d.m.

13

0.6

7

0.6

56

1.0

2,500

minus

21

0.8

d.m.

d.m.

8

0.4

5

0.5

46

0.8

5,000

minus

5

0.2

d.m.

d.m.

4*

0.2

4

0.4

42

0.7

positive control

minus

1005

36.8

d.m.

d.m.

929

41.0

505

45.9

571

10.1

 

Table 2: Mean values (with S9 mix)

 

 

TA 98

TA 100

TA 1535

TA 1537

E. coli WP2 uvrA

Concentration (µg/plate)

S9

X (n=3)

revertant factor

X (n=3)

revertant factor

X (n=3)

revertant factor

X (n=3)

revertant factor

X (n=3)

revertant factor

control

yes

42

 

d.m.

d.m.

20

 

8

 

37

 

20

yes

41

1.0

d.m.

d.m.

20

1.0

7

0.9

44

1.2

100

yes

30

0.7

d.m.

d.m.

17

0.8

6

0.7

43

1.2

500

yes

20

0.5

d.m.

d.m.

11

0.5

6

0.8

40

1.1

2,500

yes

19

0.5

d.m.

d.m.

14

0.7

11

1.4

42

1.2

5,000

yes

20

0.5

d.m.

d.m.

0*

 

8

1.0

38

1.0

positive control

yes

1023

24.4

d.m.

d.m.

125

6.2

106

13.2

161

4.4

 

 

Preincubation Test

Table 3: Mean values (without S9 mix)

 

 

TA 98

TA 100

TA 1535

TA 1537

E. coli WP2 uvrA

Concentration (µg/plate)

S9

X (n=3)

revertant factor

X (n=3)

revertant factor

X (n=3)

revertant factor

X (n=3)

revertant factor

X (n=3)

revertant factor

control

minus

28

 

123

 

20

 

10

 

48

 

4

minus

23

0.8

109

0.9

14

0.7

8

0.8

-

-

20

minus

19

0.7

124

1.0

20

1.0

10

1.0

42

0.9

100

minus

24

0.8

111

0.9

16

0.8

5

0.5

42

0.9

500

minus

27

0.9

113

0.9

14

0.7

8

0.8

49

1.0

2,500

minus

0*

 

24

0.2

5*

0.3

0*

 

26

0.5

5,000

minus

-

-

-

-

-

-

-

-

0*

 

positive control

minus

855

30.2

999

8.1

700

35.6

653

63.2

997

20.8

 

Table 4: Mean values (with S9 mix)

 

 

TA 98

TA 100

TA 1535

TA 1537

E. coli WP2 uvrA

Concentration (µg/plate)

S9

X (n=3)

revertant factor

X (n=3)

revertant factor

X (n=3)

revertant factor

X (n=3)

revertant factor

X (n=3)

revertant factor

control

yes

39

 

119

 

20

 

11

 

52

 

4

yes

39

1.0

125

1.1

18

0.9

10

0.9

-

-

20

yes

35

0.9

103

0.9

16

0.8

12

1.1

45

0.9

100

yes

38

1.0

  92

0.8

16

0.8

10

0.9

45

0.9

500

yes

30

0.8

99

0.8

13

0.7

9

0.8

50

0.9

2,500

yes

30

0.8

92

0.8

12

0.6

9

0.8

40

0.8

5,000

yes

-

-

-

-

-

-

-

-

29

0.5

positive control

yes

690

17.5

680

5.7

113

5.7

102

9.2

181

3.5

d.m.: data missing; *: reduced background

According to the results of the study, the test substance is not mutagenic in the Ames test and in the Escherichia coli - reverse mutation assay under the experimental conditions chosen here. A cytotoxic effect can be seen in some strains in the highest concentration.

Applicant's summary and conclusion

Conclusions:
Interpretation of results
negative
Executive summary:

In an OECD Guideline 471/472 study, S. typhimurium strains TA 1535, TA 1537, TA 98 and TA 100 and E. coli WP2 uvr A were exposed to the N,N-dimethylisopropylamine in water at 0, 20, 100, 500, 2500 and 5000 µg/plate in the standard plate test with and without S9-mix, and at 0, 4, 20, 100, 500 and 2500 µg/plate (Salmonella strains) or 0, 20, 100, 500, 2500 and 5000 µg/plate (E. coli WP2 uvrA) in the preincubation test with and without S9-mix (Aroclor-induced rat liver S9 mix). Positive and negative (vehicle) controls were included in the study. N,N-dimethylisopropylamine did not induce revertants in any bacterial strains tested both with and without metabolic activation, a cytotoxic effect was seen in some strains in the highest concentration.