Pentacalcium hydroxide tris(orthophosphate)

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Data source

Reference

Reference Type:

publication

Title:

In vivo Chromosome Aberration Test for Hydroxyapetite in Mice

Author:

TP Kannan, NL Nik Ahmad Shah, A Azlina, AR Samsudin, MY Narazah, Ma'arof Salleh

Year:

2004

Bibliographic source:

Med J Malaysia Vol 59 Supplement B

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 475 (Mammalian Bone Marrow Chromosome Aberration Test)

Version / remarks:

1997

Deviations:

not specified

Remarks:

the publication shows sparce information on material and methods, therefore it cannot be evaluated wheter deviations occured

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

hydroxyapatite

IUPAC Name:

hydroxyapatite

Test material form:

solid: granular

Details on test material:

synthetic hydroxyapatite granules

Test animals

Species:

mouse

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

no data

Administration / exposure

Route of administration:

intraperitoneal

Vehicle:

- Vehicle(s)/solvent(s) used: water

Details on exposure:

The treament groups were exposed to synthetic hydroxyapatite granules intraperitoneally. The cell division was arrested at metaphase by an injection of colchicine 1.5 hours prior to sacrifice. The bone marrow samples were collected 24 hours post treatment in the respective groups.

Duration of treatment / exposure:

24 hours

Frequency of treatment:

one intraperitoneal injection

Post exposure period:

none

Doses / concentrations

Remarks:

no doses are given in the publication

No. of animals per sex per dose:

five

Control animals:

yes, sham-exposed

Positive control(s):

mitomycin C
- Route of administration: intraperitoneal
- Doses / concentrations: not specified

Examinations

Tissues and cell types examined:

bone marrow

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION: no data which dose was used

no further details were provided

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

not specified

Vehicle controls validity:

not specified

Negative controls validity:

not specified

Positive controls validity:

not specified

Any other information on results incl. tables

The mean mitotic indices for the negative control, positive control and treatment groups were 3.1 ± 0.23, 2.6 ± 0.17 and 3.0 ± 0.15 respectively. No chromosome aberrations were detected both in the negative control and treatment groups whereas in the positive control group chromosome aberrations were noticed.

Applicant's summary and conclusion

Conclusions:

Negative results from the in vivo chromosome aberration test indicate that synthetic hydroxyapatite granules do not induce chromosome aberrations in the bone marrow of mice and hence is considered non-muragenic under the present test conditions.
Since no details were given regarding material and methods and results this data is not sufficient for assessment but indicates that hydroxyapatite has no genotoxic potential under the present test coditions.