N-ethylpyridazin-4-amine

Genetic toxicity: in vitro

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)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

The applied test method is a modified version of the Ames test (OECD 471), designated Ames II Assay (microtiter version). The method is used to evaluate the mutagenic potential of the test chemical based on the ability to induce point mutations in selected loci of several strains of Salmonella typhimurium, both with and without the addition of a metabolizing system (S9 mix).

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

N-ethylpyridazin-4-amine

EC Number:

846-827-8

Cas Number:

1521274-68-9

Molecular formula:

C6H9N3

IUPAC Name:

N-ethylpyridazin-4-amine

Details on test material:

- State of aggregation: solid/brown

Method

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 98

Species / strain 2

Species / strain / cell type:

S. typhimurium, other: TA Mix (TA 7001 - TA 7006)

Metabolic activation:

with and without

Metabolic activation system:

Type and composition of metabolic activation system:
- source of S9: induced male Wistar rats
- volume of S9 mix in the final culture medium: 40 µL S9 mix + 200 µL Bacteria suspension + 10 µL Test substance or vehicle or positive control
- quality controls of S9 (e.g., enzymatic activity, sterility, metabolic capability)

Test concentrations with justification for top dose:

Doses: 0; 4; 20; 100; 500; 2500 and 5000 µg/mL

Vehicle / solvent:

- Vehicle used: DMSO

Controls

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

2-nitrofluorene

Details on test system and experimental conditions:

NUMBER OF REPLICATIONS:
- Number of cultures per concentration: 2
- Number of independent experiments: 3

METHOD OF TREATMENT/ EXPOSURE:
- Cell density at seeding (if applicable): Bacteria suspension OD > 2.0 (600 nm) mixed with Ames II Exposure medium (1:6)
- Test substance added in medium: 10 µL/250 µL

TREATMENT
- duration of treatment: 90 min
- 48 h incubation with Ames II Reversion indicator medium

Evaluation criteria:

Evaluation was performed by the following comparisons/calculation:
- An increase in the mean number of positive wells in dose groups was compared to the
mean value of the concurrent negative control (Evaluation factor 1 F).
- An increase in the mean of revertant wells in dose groups was calculated on the basis
of the baseline data of the actual experiment (Evaluation factor 2 F). The baseline was
derived from the mean spontaneous revertant number plus the value of standard
deviation (mean + SO) from the distribution of spontaneous data.
- An increase in the mean of revertant wells in dose groups was calculated on the basis
of the baseline data of an experimental run (Evaluation factor 3 F). A run consists of a
variable number of experiments generally testing different test substances together
each using the same vehicle control. This leads to an accumulation of replicates for
negative controls which was used to calculate the mean spontaneous reversion
number for each run.
A test substance is considered mutagenic in this test system if more than a doubling of
Evaluation factor 3 F is observed in at least one test group.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium, other: TA Mix (TA 7001 - TA 7006)

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Under the experimental conditions, the test substance did not show a mutagenic potential in the Ames II Assay (Salmonella typhimurium reverse mutation assay), both with or without metabolic activation.