Tin sulphide

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: genome mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-01-04 to 2010-03-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and guideline compliant study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2011

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Version / remarks:

, 1997

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

Tin sulfide

IUPAC Name:

Tin sulfide

Constituent 2

Reference substance name:

Tin sulphide

EC Number:

215-248-7

EC Name:

Tin sulphide

Cas Number:

1314-95-0

Molecular formula:

SSn

IUPAC Name:

stannanethione

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: BioTest s. r. o., Pod Zámkem 279, Konárovice, Czech Republic
- Age at study initiation: 8-10 weeks
- Weight at study initiation: Males 250 g, Females 170 g
- Assigned to test groups randomly: yes, under following basis: sorted according to the body weight and randomly allocated to the dose group taking animals from each range group
- Water: ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24 °C
- Humidity (%): 30-70 %
- Photoperiod (hrs dark / hrs light): 12 hrs/12 hrs

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: methylcellulose 0.5%

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
Each animal in treated groups received the appropriate dose of Test item suspension orally by gavage in the volume of 1 mL per 100 g body weight. The animals in the negative control group received the appropriate volume of saline solution by the same way. The animals in the positive control group were administered cyclophosphamide solution at the dose of 20 mg/kg by a single intraperitoneal application in the volume of 1 mL per 100 g body weight.
The following procedure was adopted for the preparation of a homogenous suspension: at first the we ighed amount of the respective substance was ground in a grinding mortar with a small volume of carrier liquid. Then the content of the mortar was transferred into a calibrated vessel. Another amount of carrier liquid was poured into the mortar, stirred and the mortar with the pestle was rinsed, the rinsing liquid was added into the same calibrated vessel. This rinsing procedure was repeated once more. Then the volume in the calibrated vessel was made up with the carrier liquid to the required volume and mixed. Immediately before the application, the suspension was again stirred by means of an electromagnetic
stirrer.

Duration of treatment / exposure:

Duration of administration was 10-20 s

Frequency of treatment:

single exposure

Post exposure period:

One half of the animals from each group were sacrificed 24 hours after the administration and the other half of animals were sacrificed 48 hours after the administration.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 mg/kg bw/day (actual dose received)

Remarks:

single exposure

Doses / concentrations 2

Dose / conc.:

500 mg/kg bw/day (actual dose received)

Remarks:

single exposure

Doses / concentrations 3

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

Remarks:

single exposure

Doses / concentrations 4

Dose / conc.:

2 000 mg/kg bw/day (actual dose received)

Remarks:

single exposure

No. of animals per sex per dose:

Number of animals per group: 10 Males + 10 Females

Control animals:

yes, concurrent vehicle

Positive control(s):

cyclophosphamide

- Route of administration: i.p.
- Doses / concentrations: 20 mg/kg

Examinations

Tissues and cell types examined:

bone marrow (mean number of NCPE, PCE, NCE and proportion of immature erythrocytes)

Details of tissue and slide preparation:

During the necropsy the bone marrow was extracted from femur using bovine serum into a labeled test tube. The cells were centrifuged (1000 rpm for 10 min). The supernatant was removed and the sediment was resuspended in approx. 4 drops of bovine serum. Smear preparations from this suspension were made in duplo for each animal and fixed with methanol for 5 min and then stained with Giemsa–Romanowski (1:10) for 15-20 min.
All the slides were independently coded before blind microscopic analysis.

Evaluation criteria:

At least 2000 polychromatic (immature) erythrocytes per animal were scored for the incidence of micronuclei under the microscope. The proportion of polychromatic (immature) among total (immature + mature or polychromatic + normochromatic) erythrocytes were determined for each animal by counting a total of at least 200 erythrocytes.

Statistics:

The analyzed data were tested for normality (Kolmogorov–Smirnov test) and homogeneity of variance (Bartlett’s test).
The data for males and females were separately analyzed using ANOVA followed by Dunnett’s Multiple Comparison Test. The F-test in the ANOVA tests whether there are any significant differences amongst the means at the 95.0 % confidence level.

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Tin sulphide does not produce micronuclei in the immature erythrocytes in the conditions of the test.

Applicant's summary and conclusion

Conclusions:

Interpretation of results: negative
Tin sulfide does not produce micronuclei in the immature erythrocytes in the conditions of the test.

Executive summary:

The potential of tin sulfide to cause cytogenetic damage was assessed in a Mammalian Erythrocyte Micronucleus Test according to OECD guideline 474.

No changes in health status and condition of the animals in any of the groups were recorded during the acclimation and during the study. No significant changes of mean body weight were observed in the animals during the study. All the values of number of NPCE in all dose groups were within the reference range for negative control group. No statistically significant higher values of number of NPCE in any of the dose groups (up to 11 of micronuclei) as compared to negative control group (up to 13 of micronuclei) were noted. Statistically significant differences were observed in the positive control group (NPCE – up to 38 of micronuclei) as compared to control group.

Tin sulfide does not induce damage to the chromosomes or the mitotic apparatus of erythroblasts.