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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian cell study: DNA damage and/or repair
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2015
Report date:
2015

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 489 (In vivo Mammalian Alkaline Comet Assay)
Deviations:
yes
Remarks:
See the the “Any other information on materials and methods" section for protocol deviations.
GLP compliance:
yes
Type of assay:
mammalian comet assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Potassium 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctanesulphonate
EC Number:
261-818-3
EC Name:
Potassium 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctanesulphonate
Cas Number:
59587-38-1
Molecular formula:
C8H5F13O3S.K
IUPAC Name:
potassium 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctane-1-sulfonate
Test material form:
solid: particulate/powder
Details on test material:
- Purity: 97.6%

Test animals

Species:
rat
Strain:
other: Crl:CD(SD)
Details on species / strain selection:
The rat was selected as there is a large volume of background data in this species.
Sex:
male

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
Water
Duration of treatment / exposure:
2 doses
Frequency of treatment:
Two administrations at 0 (Day 1) and 21 hours (Day 2)
Post exposure period:
No
Doses / concentrationsopen allclose all
Dose / conc.:
500 mg/kg bw/day (nominal)
Dose / conc.:
1 000 mg/kg bw/day (nominal)
Dose / conc.:
2 000 mg/kg bw/day (nominal)
No. of animals per sex per dose:
6 male animals
Control animals:
yes, concurrent vehicle

Examinations

Tissues and cell types examined:
Liver and stomach tissues were examined for DNA damage in the Comet assay
Evaluation criteria:
The following criteria were used for analysis of slides:

1. Only clearly defined non overlapping cells were scored
2. Clouds were not scored
3. Cells with unusual staining artefacts were not scored.

For valid data, the test article was considered to induce DNA damage if:
1. A least one of the test doses exhibits a marked increase in tail intensity, in any tissue, compared with the concurrent vehicle control
2. The increase is dose related in any tissue.

The test article was considered positive in this assay if both of the above criteria were met. The test article was considered negative in this assay if neither of the above criteria were met. Results which only partially satisfied the criteria were dealt with on a case-by-case basis. Biological relevance was taken into account, for example consistency of response within and between dose levels. A positive response was based on scientific judgment and included analysis of related, concurrent cytotoxicity information (such as ‘cloud’ assessment) and the historical control data.
Statistics:
Statistical analysis was conducted on tail intensity data only according to the recommendations of Bright et al., 2011. The positive control group was compared to the vehicle control using a two sample t-test. Vehicle control and test groups were analysed separately using one-way analysis of variance (ANOVA). An overall dose response test was performed along with Dunnett’s test for pairwise comparisons of each treated group with the vehicle control. All tests were performed with one-sided risk for increased response with increasing dose. Levene’s test for equality of variances across the groups was also performed and where test showed evidence of heterogeneity (p≤0.01), the data were rank-transformed prior to analysis. High levels of ‘clouds’ indicated the nuclear complex had been significantly fragmented and was considered evidence of excessive DNA damage. Such damage may be due to the cytotoxic nature of the treatment or due to excessive mechanical disruption during cell isolation, which had the potential to interfere with Comet analysis.

Results and discussion

Test results
Key result
Sex:
male
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls validity:
valid
Negative controls validity:
not examined
Positive controls validity:
valid
Remarks on result:
other: Test substance did not induce DNA damage in the liver and stomach of rats treated up to 2000 mg/kg/day (the maximum recommended dose for in vivo Comet studies according to current regulatory guidelines).

Applicant's summary and conclusion

Conclusions:
The test substance did not induce DNA damage in the liver and stomach of rats treated up to 2000 mg/kg/day (the maximum recommended dose for in vivo Comet studies according to current regulatory guidelines).
Executive summary:

The study was conducted to determine the potential of test substance to induce DNA damage in the liver and stomach of treated male rats according to guideline OECD 489. The study was conducted using test concentrations of 500, 1000 and 2000 mg/kg/day and a positive control using ethyl methanesulfonate 150 mg/kg, single administration at 21 hours (Day 2). Observations were made immediate, 1, 2 and 4 hours post dose on Day1 and Pre-dose, immediate and prior to necropsy on Day 2.

No signs of toxicity observed in any animal dosed with vehicle, test substance or positive control. There was a dose-related loss of body weight following dosing with test substance. Vehicle control data were comparable with the laboratory’s historical data. The positive control induced a significant increase in Comet parameters compared to the concurrent vehicle control. The study was therefore accepted as valid.

There was no dose-related increase in %clouds in liver and stomach following treatment with test substance, thus demonstrating that treatment with test substance did not cause excessive DNA damage (which can interfere with Comet analysis) following oral gavage administration. In the liver and stomach, group mean tail intensities and tail moments for groups treated with test substance at all dose levels were considered to be similar to the concurrent vehicle control group. There were no statistically significant increases in tail intensity in either tissue at any dose level compared to the concurrent vehicle control group. A small decrease in group mean tail intensity in stomach at 1000 mg/kg/day was observed, however, this was attributed to low variability of tail intensities within the dose group. As the individual animal tail intensities were comparable with those of at least one concurrent vehicle control animal and showed no evidence of a dose response, the decrease in group mean tail intensity was attributed to a chance event. It is concluded that, under the conditions of this study, test substance did not induce DNA damage in the liver and stomach of rats treated up to 2000 mg/kg/day (the maximum recommended dose for in vivo Comet studies according to current regulatory guidelines).  

In the liver and stomach, group mean tail intensities and tail moments for groups treated with the test substance at all dose levels were considered to be similar to the concurrent vehicle control group. There were no statistically significant increases in tail intensity in either tissue at any dose level compared to the concurrent vehicle control group. A small decrease in group mean tail intensity in stomach at 1000 mg/kg/day was observed, however, this was attributed to low variability of tail intensities within the dose group. As the individual animal tail intensities were comparable with those of at least one concurrent vehicle control animal and showed no evidence of a dose response, the decrease in group mean tail intensity was attributed to a chance event.

It is concluded that, under the conditions of this study, the test substance did not induce DNA damage in the liver and stomach of rats treated up to 2000 mg/kg/day (the maximum recommended dose for in vivo Comet studies according to current regulatory guidelines).