Trometamol

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals

Deviations:

no

GLP compliance:

yes

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

2-amino-2-ethyl-1,3-propanediol

IUPAC Name:

2-amino-2-ethyl-1,3-propanediol

Details on test material:

- Name of test material (as cited in study report): 2-amino-2-ethyl-1,3-propanediol
- Analytical purity: 99.4%

Method

Target gene:

not applicable

Species / strain

Species / strain / cell type:

mammalian cell line, other: Chinese hamster lung (CHL/IU) cells

Details on mammalian cell type (if applicable):

- Type and identity of media: Eagle´s MEM with 10 vol.% calf serum (deactivated)

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

cofactor supplemented post-mitochondrial fraction (S9-mix), prepared from the livers of rats treated with treated with phenobarbital and 5,6-benzoflavone

Test concentrations with justification for top dose:

without S9 mix(short-term treatment, continuous treatment 24 h and 48 h): 75, 150, 300, 600 and 1200 μg/mL
with S9 mix(short-term treatment): 75, 150, 300, 600 and 1200 μg/mL

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: physiol. saline

Controls

Untreated negative controls:

yes

Remarks:

medium

Negative solvent / vehicle controls:

yes

Remarks:

physiol. saline

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: without S9 mix: Mitomycin C (0.05 µg/mL), with S9 mix: Cyclophosphamide (15 µg/mL)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION
- Exposure duration: 6 h (short time treatment), 24 and 48 h (continuous treatment)
- Expression time (cells in growth medium): 18 h (for short time treatment)

SPINDLE INHIBITOR (cytogenetic assays): colcemide (final concentration: 0.2 µg/mL)
STAIN (for cytogenetic assays): Giemsa stain (2 vol.%)

NUMBER OF REPLICATIONS: 2 plates per test, 1 experiment

NUMBER OF CELLS EVALUATED: 200 metaphase images per dose (100 per plate)

DETERMINATION OF CYTOTOXICITY
- Method: The cell multiplication inhibiting action of the test substance was determined by measuring the cell density using a single-layer cultured cell densitometer and using the ratio of the cell density of the test group and of the negative group.

Evaluation criteria:

The judgment was made according to the criteria of Ishidate et al. (1987). When the frequencies of appearance of the cells with chromosomal aberrations (CA) were < 5%, the results were considered negative; when the frequencies of CA were 5% or > 5%, the results were considered false positive; when the frequencies of CA were 10% or greater, the results were considered positive. Finally, in the cases in which dose dependence or reproducibility was observed the appearance of aberrant cells, the results were considered positive.

Results and discussion

Test results

Key result

Species / strain:

mammalian cell line, other: Chinese hamster lung (CHL/IU) cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

RANGE-FINDING/SCREENING STUDIES:
Based on the results of performing cell multiplication inhibition tests, it was decided to use a test concentration range of 75-1200 µg/mL.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

No increase in chromosomal aberrations was observed in the test with either the short- term treatment (without S9 mix and with S9 mix) or continuous treatment.

Table 1: Results of experiments

Test item	Concentration	Cell growth ratio [mean in %]*	Aberrant cells in %
	in µg/mL	in %	with gaps	without gaps
Exposure period 6-18 h, fixation time 24h, without S9 mix
saline	0.9%	100	2.5	1.0
MMC	0.05	79	25	24
Test substance	75	93	2.5	1.0
	150	93	3.0	1.5
	300	86	2.5	0.5
	600	86	2.0	1.0
	1200	79	2.0	1.5
Exposure period 6-18 h, fixation time 24h, with S9 mix
saline	0.9%	100	1.0	0
CP	15	93	79.0	79.0
Test substance	75	107	1.5	1.5
	150	93	1.0	0.5
	300	100	2.0	1.0
	600	93	2.0	1.0
	1200	85	2.5	1.5
Exposure period 24h, fixation time 24h, without S9 mix
saline	0.9%	100	4.0	2.0
MMC	0.05	89	43.5	42.0
Test substance	75	89	3.0	0.5
	150	89	3.0	1.0
	300	111	2.5	1.0
	600	89	2.5	0.5
	1200	67	4.9	3.7
Exposure period 48h, fixation time 48h, without S9 mix
saline	0.9%	100	3.0	0.5
MMC	0.05	94	68.0	66.5
Test substance	75	100	1.5	0
	150	106	1.5	0.5
	300	106	4.0	1.5
	600	100	1.5	0.5
	1200	50	4.8	3.6

MMC: Mitomycin C; CP: Cyclophosphamide (positive controls)

* The mean value showed as a growth ratio against the negative control value.

 

Applicant's summary and conclusion

Conclusions:

Interpretation of results: negative