Registration Dossier

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: DNA damage and/or repair
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study performed to GLP and guideline

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
GLP compliance:
yes
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Calcium sulfate, dihydrate
- Analytical purity: 99.9%
- Lot/batch No.: Sigma Aldrich LOT no. - 109H0166

Test animals

Species:
mouse
Strain:
ICR
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: 8 weeks

Administration / exposure

Route of administration:
oral: feed
Vehicle:
- Vehicle(s)/solvent(s) used: CMC (carboxymethyl cellulose)
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:Calcium sulfate, dihydrate was dissolved in 1 % CMC (Sodium carboxymethyl Cellulose) and supersonic wave was used to prepare the highest dose concentration.



Duration of treatment / exposure:
1 day
Frequency of treatment:
Single treatment
Doses / concentrationsopen allclose all
Dose / conc.:
1 250 mg/kg bw/day
Dose / conc.:
2 500 mg/kg bw/day
Dose / conc.:
5 000 mg/kg bw/day
No. of animals per sex per dose:
6
Positive control(s):
- mitomycin C
- Doses / concentrations: 0.5 mg/kg and 1.0 mg/kg

Examinations

Details of tissue and slide preparation:
To observe the cell multiplication of bone marrow, a specimen was fixed with methanol. And 4 % Giemsa solution was used for dyeing to observe the ratio of polychromatic erythrocytes. To observe the micronucleus in the polychromatic erythrocytes, 40 μg/ml acridine was dropped for dyeing



Evaluation criteria:
At least 2000 polychromatic erythrocytes per animal were scored for the incidence of micronuclei
Statistics:
ANOVA (using Sigmastat 2.0 statistic programme)

Results and discussion

Test results
Sex:
male
Genotoxicity:
negative
Remarks on result:
other: Calcium sulfate dihydrate showed negative results in the micronucleus test in vivo up to the test concentration of 5000 mg/kg b.w

Any other information on results incl. tables

Table 1: Effect on mitotic index or PCE/NCE ratio by dose level.

Dose (mg/kg)

Group mean

(PCE/(PCE+NCE)) (%)

Group mean frequency of

MNPCE

(per 1,000)

Vehicle

1,250

2,500

5,000

Positive control (0.5mg/kg)

Positive control (1.0mg/kg)

60.49±7.77

56.58±9.07

54.61±6.13

54.48±9.02

46.58±10.76

46.96±7.08

6.5

7.0

7.7

8.0

19.2

44.8

Applicant's summary and conclusion

Conclusions:
negative
Calcium sulfate dihydrate showed negative results in the micronucleus test in vivo up to the test concentration of 5000 mg/kg b.w