Ethylamine

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)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

only 4 strains were tested

Data source

Reference

Reference Type:

publication

Title:

Salmonella mutagenicity tests: II. Results from the testing of 270 chemicals

Author:

Mortelmans, K., et al.

Year:

1986

Bibliographic source:

Environmental Mutagenesis, 7: 1-119

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The test substance was assayed for mutagenicity in the Salmonella/microsome preincubation assay using a standard protocol approved by the National Toxicology Program [see also Haworth et al, 1983].
To the 13 X 100-mm test tube maintained at 37°C the following substances were added:
0.5 ml of S-9 mix or 0.1 M PO4 buffer (pH 7.4), 0.05 ml of the overnight culture, and 0.05 ml of solvent or chemical dilution.

The mixture was mixed and allowed to incubate without shaking at 37°C for 20 min, at which time 2.0 ml of molten (45°C) top agar supplemented with 0.5 mM L-histidine and 0.5 mM D-biotin were added. The contents of the tubes were mixed and poured onto 25 ml of minimal glucose bottom agar [Vogel and Bonner, 1956] in 15 X 100-mm plastic petri dishes (Falcon Muta-Assay, 1028). When the top agar had solidified, the plates were inverted and incubated at 37°C for 48 hr. Concurrent solvent and positive controls were tested with and without the metabolic activation systems. Five dose levels of the test substance was tested, with three plates per dose level in four strains.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Ethylamine

EC Number:

200-834-7

EC Name:

Ethylamine

Cas Number:

75-04-7

Molecular formula:

C2H5NH2

IUPAC Name:

ethanamine

Details on test material:

- Name of test material (as cited in study report): Ethylamine
- Analytical purity: no data

Specific details on test material used for the study:

- Supplier: Fluka Chemical Co.
- Testing lab: SRI

Method

Target gene:

Histidine

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Metabolic activation system:

Type and composition of metabolic activation system:
- source of S9: Male Sprague-Dawley rats and male syrian hamsters; liver S9
- method of preparation of S9 mix: Aroclor 1254 (200 mg/ml in corn oil) was administered ip at 500 mg/kg 5 days prior to decapitation (EGG, SRI) or cervical dislocation (CWR). The animals were deprived of food 12-24 hr immediately preceding death; otherwise food and water were provided ad libitum. The livers were removed aseptically, washed in ice-cold 0.15 M KCl, and minced and homogenized (3 ml of 0.15 M KC1 per gm of wet tissue) in a Potter-Elvehjem apparatus with a Teflon pestle. CWR initially used a Waring blender, but switched to a Potter-Elvehjem apparatus. The S-9 fraction was obtained by centrifugation of the liver homogenate for 10 min at 9,000 g at 4°C. The S-9 mix was prepared immediately prior to each assay.
- Volumes of S9 mix:
Per milliliter:
S-9 fraction 0.10 ml
0.04 M MgC12 0.02 ml
1.65 M KC1 0.02 ml
0.04 M NADP 0.10 ml
0.05 M glucose-6-phosphate 0.10 ml
1.0 M NaH2P04, (pH 7.4) 0.10 ml
Distilled water 0.56 ml

Test concentrations with justification for top dose:

0, 100, 333, 1000, 3333, 10000 ug/plate

Vehicle / solvent:

Water

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

Potassium chloride

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

sodium azide

other: -4-nitro-o-phenylenediamine for TA98; - with metabolic activation: 2-aminoanthracene (all strains).

Details on test system and experimental conditions:

NUMBER OF REPLICATIONS:
- Number of cultures per concentration: 3

METHOD OF TREATMENT/ EXPOSURE:
- preincubation test

TREATMENT AND HARVEST SCHEDULE:
- Preincubation period: 20 min
- Exposure duration: 48 h

FOR GENE MUTATION:
- Ames test

Evaluation criteria:

1) Mutagenic response: a dose-related, reproducible increase in the number of revertants over background, even if the increase was less than twofold
2) nomutagenic response: when no increase in the number of revertants was elicited by the chemical
3) questionable response: when there was an absence of a clear-cut dose-related increase in revertants; when the dose-related increases in the number of revertants were not reproducible;
or when the response was of insufficient magnitude to support a determination of mutagenicity

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: 10000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: 10000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: 10000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: 10000µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

GENOTOXIC EFFECTS:
- With metabolic activation: negative
- Without metabolic activation: negative

PRECIPITATION CONCENTRATION:
- No precipitate observed

CYTOTOXIC CONCENTRATION:
- With metabolic activation: 10000 ug/plate
- Without metabolic activation: 10000 ug/plate

Any other information on results incl. tables

Strain: TA1535

Dose	No Activation (Negative)		10% HLI (Negative)		10% RLI (Negative)
Protocol	Preincubation		Preincubation		Preincubation
ug/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM
0	33	2.3	11	2.6	15	0.3
100	30	4.9	10	2.3	10	3
333	25	3.5	9	1.7	11	3.8
1000	30	2.7	11	2	10	0.9
3333	7s	4.1	15	3.5	18	1.7
10000	0s	0	0s	0	0s	0
Positive Control	342	42.1	245	10.7	178	24.1

 

Strain: TA100

Dose	No Activation (Negative)		10% HLI (Negative)		10% RLI (Negative)
Protocol	Preincubation		Preincubation		Preincubation
ug/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM
0	146	10.4	121	2.7	121	6.5
100	118	5.1	114	8.6	136	11.5
333	129	9.4	132	5.7	116	10.3
1000	108	5.2	143	9.4	108	9.3
3333	118	9	121	16.9	94	11.1
10000	0s	0	0s	0	41s	20.5
Positive Control	377	8.7	966	42.3	456	24.8

 

Strain: TA98

Dose	No Activation (Negative)		10% HLI (Negative)		10% RLI (Negative)
Protocol	Preincubation		Preincubation		Preincubation
ug/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM
0	16	2	26	5.7	25	1.9
100	17	1.7	32	2.3	27	3.5
333	13	3.1	32	3.2	25	0.6
1000	12	3.2	34	4.7	32	2.3
3333	8s	4.3	0s	0	23	4.5
10000	t		t		0s	0
Positive Control	475	108.7	764	21.3	326	10.7

 

Strain: TA1537

Dose	No Activation (Negative)		10% HLI (Negative)		10% RLI (Negative)
Protocol	Preincubation		Preincubation		Preincubation
ug/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM
0	5	1.5	5	1.5	6	1.7
100	11	2.1	7	1.2	6	1
333	5	1.3	4	1	7	1.2
1000	6	3.2	7	1.2	4	0.7
3333	4	1.7	0s	0	3	0.7
10000	0s	0	t		0s	0
Positive Control	350	41.7	406	11.5	135	8.7

  

Abbreviations:
RLI = induced male Sprague Dawley rat liver S9
HLI = induced male Syrian hamster liver S9
s = Slight Toxicity; p = Precipitate; x = Slight Toxicity and Precipitate; T = Toxic; c = Contamination

Applicant's summary and conclusion

Conclusions:

Based on the results of this publication, the test substance is negative in the Salmonella/microsome preincubation assay with and without metabolic activation.

Executive summary:

The test substance was evaluated for mutagenicity in the Salmonella/microsome preincubation assay using a standard protocol approved by the National Toxicology Program. Doses of 0, 100, 333, 1000, 3333 and 10000 ug/plate were tested in four Salmonella typhimurium strains (TA98, TA100, TA1535, and TA1537) in the presence and absence of Aroclor-induced rat or hamster liver S9. The test substance was evaulated as negative in all experiments.