o-phenylenediamine

Genetic toxicity: in vivo

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

Reference

Reference 1

Reference Type:

publication

Title:

Unnamed

Year:

1980

Reference 2

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 3

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

Test material information

Constituent 1

Reference substance name:

95-45-5

IUPAC Name:

95-45-5

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 / concentrations

Doses / concentrations 1

Dose / conc.:

108 other: mg/kg

Doses / concentrations 2

Dose / conc.:

216 other: mg/kg

Doses / concentrations 3

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 values^c
O-phenylene-diamine (0.9% NaCl)
	Guinea pig	i.p.	2 x 324	3/3	0.05	33.8^a	13-62
			2 x 216	3/3	0.21	16.0^a	6-28
			2 x 108	3/3	0.21	6.5^b	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.