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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Unnamed
Year:
1980
Reference Type:
publication
Title:
The in vivo micronucleus assay in mammalian bone marrow and peripheral blood. A report of the U.S. Environmental Protection Agency gene-tox program.
Author:
Mavournin, K.H., Blakey, D.H., Cimino, M.C., Salamone, M.F., and Heddle, J.A.
Year:
1992
Bibliographic source:
Mutat. Res., 239:29-80 (cited in Yang, W.L., Klopman, G. and Rosenkranz, H.S. (1992) Structural basis in the in vivo induction of micronuclei. Mutat. Res., 272(2):111-124.
Reference Type:
publication
Title:
Mutagenic effects of the ortho-phenylenediamine in mammalian somatic and germ cells.
Author:
Wild, D. Gocke, E. and Turan, Z.
Year:
1981
Bibliographic source:
Mutat. Res., 85(4):292

Materials and methods

Principles of method if other than guideline:
The micronucleus test was conducted with animals receiving 2 equal doses separated by a 24 hour interval. Six hours after the second dose, bone marrow was isolated. Smears were prepared and stained with May-Grünwald and Giesma. Slides were coded and usually 1000 polychromatic erythrocytes (PCEs) from each animal were analyzed for micronuclei.
GLP compliance:
no
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Test substance( as cited in study report): o-phenylenediamine
Purity: 99%.
Purchased from: Fluka AG.

Test animals

Species:
guinea pig
Strain:
other: albino
Sex:
male/female

Administration / exposure

Route of administration:
intraperitoneal
Vehicle:
0.9% NaCl
Details on exposure:
MICRONUCLEUS TEST:
- Animals received 2 equal doses separated by a 24 hour interval.
- Six hours after the second dose, bone marrow was isolated.
- Smears were prepared and stained with May-Grünwald and Giesma.
- Slides were coded and usually 1000 polychromatic erythrocytes (PCEs) from each animal were analyzed for micronuclei.
- Cytogenetic damage is expressed by an increased frequency of micronucleus-containing PCEs.
- The proportion of polychromatic among total (poly and normo-chromatic) PCEs (PE/PE + NE) is based on the differentiation of 1000 total erythrocytes.
Duration of treatment / exposure:
The injections were 24 hours apart.
Frequency of treatment:
Two i.p. injections
Doses / concentrationsopen allclose all
Dose / conc.:
108 other: mg/kg
Dose / conc.:
216 other: mg/kg
Dose / conc.:
324 other: mg/kg
No. of animals per sex per dose:
Three male and female guinea pigs per exposure group and control (12 total guinea pigs.)
Control animals:
yes, concurrent vehicle

Examinations

Tissues and cell types examined:
bone marrow
Details of tissue and slide preparation:
6 hr after the second dose bone marrow was isolated, smears were prepared and stained with May-Grunwald and Giemsa; slides were coded and usually 1000 polychromatic erythrocytes from each animal were analyzed for micronuclei.

Results and discussion

Test results
Genotoxicity:
positive
Additional information on results:
- All doses were non-lethal under the experimental conditions.
- The test substance (TS) produced a higher percentage of micronucleated polychromatic erythrocytes (MPEs.)
- i.p.: Significant increase in all dose groups compared to the control.

- oPDA was active at 2 doses of 108 mg/kg and at higher doses.
- There was considerable not sex-related interindividual variation of the cytogenetic effect.

Any other information on results incl. tables

.

Table 1. Micronucleus tests with ortho-phenylenediamine on bone marrow of Guinea pigs

Chemical (vehicle)

Species

Route of Application

Dose (mg/kg)

Surviving/ treated animals

PE / (PE + NE)

Micronucleated / Total PE

Mean %

Range of valuesc

O-phenylene-diamine (0.9% NaCl)

Guinea pig

i.p.

2 x 324

3/3

0.05

33.8a

13-62

2 x 216

3/3

0.21

16.0a

6-28

2 x 108

3/3

0.21

6.5b

3-11

0

3/3

0.25

3.2

2-5

PE: polychromatic erythrocytes, NE: normochromatic erythrocytes

ap≤0.01, bp≤0.05

cWhole numbers are given, the actual experimental values can slightly differ because occasionally slightly more than 1000 PE were analyzed.

Applicant's summary and conclusion

Conclusions:
Chromosomal damage was detected in guinea pigs following intraperitoneal injections of the TS. Specifically, a dose-dependent increase in the mean percentage of micronucleated polychromatic erythrocytes was observed for 108 mg/kg and above.
Executive summary:

Chromosomal damage was detected in guinea pigs following intraperitoneal injections of the TS. Specifically, a dose-dependent increase in the mean percentage of micronucleated polychromatic erythrocytes was observed for 108 mg/kg and above.