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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro cytogenicity / chromosome aberration study in mammalian cells
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
1994
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1994
Report Date:
1994

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)
Deviations:
not specified
GLP compliance:
not specified
Type of assay:
in vitro mammalian chromosome aberration test

Test material

Reference
Name:
Unnamed
Type:
Constituent
Specific details on test material used for the study:
- Name of test material (as cited in study report): barium chloride dihydrate
- EC number: 233-788-1
- Substance type: pure active substance
- Physical state: a white crystalline granule or powder

Method

Species / strain
Species / strain:
Chinese hamster Ovary (CHO)
Details on mammalian cell lines (if applicable):
no details available
Metabolic activation:
with and without
Metabolic activation system:
S9-mix
Controlsopen allclose all
Negative controls:
no
Solvent controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
mitomycin C
Negative controls:
no
Solvent controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
cyclophosphamide
Details on test system and conditions:
METHOD OF APPLICATION: in medium, duplicate cultures

DURATION (test without S9)
- Exposure duration: In the test without S9, cells were incubated with barium chloride dihydrate for 10 hours.
Spindel inhibitor: (cytogenetic assays): Colcemid was added and incubation continued for 2 hours.
Stain: (for cytogenetic assays): The cells were then harvested by mitotic shake-off, fixer, and stained with Giemsa.

DURATION (test with S9)
- Exposure duration: In the test with S9, cells were treated with barium chloride dihydrate and S9 for 2 hours, after which the treatment medium was removed and the cells were incubated for 10 to 11 hours in fresh medium.
Spindel inhibitor: (cytogenetic assays): Colcemid was added for the final 2 hours.
Stain: (for cytogenetic assays): The cells were then harvested by mitotic shake-off, fixer, and stained with Giemsa.

NUMBER OF CELLS EVALUATED: One hundred first-division metaphase cells were scored at each dose level. Classes of aberrations included simple (breaks and terminal deletions), complex (rearrangements and translocations), and other (pulverised cells, despiralised chromosomes, and cells containing 10 or more aberrations).
Evaluation criteria:
no data
Statistics:

CA data are presented as percentage of cells with aberrations. To arrive at a statistical call for a trial, analyses were conducted on both the dose response curve and individual dose points. For a single trial, a statistically significant (P<0.05) difference for one dose point and a significant trend (P<0.015) are considered weak evidence for a positive response; significant differences for two or more doses indicate the trial is positive. A positive trend test in the absence of a statistically significant increase at any one dose results in an equivocal call (Galloway et al., 1987).

Results and discussion

Test results
Species / strain:
Chinese hamster Ovary (CHO)
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
not specified
Vehicle controls valid:
yes
Negative controls valid:
not examined
Positive controls valid:
yes
Additional information on results:
no data

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
The in vitro chromosome aberration test in CHO cells was negative with and without metabolic activation.