o-phenylenediamine

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: other: damage of chromosomes or mitotic apparatus

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Important aspects are in line with current OECD guidelines

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Report date:

1980

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

not specified

GLP compliance:

yes

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

o-phenylenediamine

EC Number:

202-430-6

EC Name:

o-phenylenediamine

Cas Number:

95-54-5

Molecular formula:

C6H8N2

IUPAC Name:

benzene-1,2-diamine

Details on test material:

- Name of test material (as cited in study report): Hoe 37197 O T AT201 (o-Phenylendiamin)

Test animals

Species:

mouse

Strain:

other: NMRI strain Hoe NMRKf (SPF71)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Pharma Forschung Toxikologie, Kastengrund, Hattersheim, Germany
- Age at study initiation: 10-12 weeks
- Weight at study initiation: male: 32 - 40 g, female: 23 - 29 g
- Assigned to test groups randomly: yes
- Fasting period before study: no fasting period
- Housing: plastic cages, groups of five, same-sex
- Diet ad libitum: yes
- Water ad libitum: yes
- Acclimation period: not specified

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

Deionised water for the test substance and aqua dest. for the positive control

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:

DOSE PREPARATION
- Rate of preparation: daily before application,
- Stock solution: 1250 mg test substance ad 50 ml
- Dose concentrations: dilutions of stock solution

Duration of treatment / exposure:

In a range finder test 250 mg/kg bw. was found to be the max. tolerable dose.
Two applications at 24 hours intervals. 6 hours after the second application the animals were killed.

Frequency of treatment:

Two applications at 24 hours intervals.

Post exposure period:

6 hours after the second application the animals were killed.

Doses / concentrations

Remarks:

Doses / Concentrations:
0; 2.5; 25; and 250 mg/kg bw.
Basis:
other: nominal dose administered

No. of animals per sex per dose:

5 male and 5 female mice

Control animals:

yes, concurrent no treatment

Positive control(s):

Cyclophophamid (Endoxan, Edoxan W.Z. of company Asta, Brackwede): 100 mg/kg bw

Examinations

Tissues and cell types examined:

bone marrow erythroctes

Details of tissue and slide preparation:

Cells are removed from femures and poured in 5 ml of fetal calf's serum. The mixture was centrifuged at 1000 RPM. One drop of the cell suspension was spread on an object slide and dried for 24h at room temperature. Staining was done using May-Grünwaldt- and Giesema-solution.

Evaluation criteria:

2000 polychromatic erythorcytes were examined for micronuclei containing cells. Additionally 1000 monochromatic erythrocytes were examined for micronuclei containing cells.

Statistics:

Binomial distribution, for increase, 90% confidence interval
Nemeny / Dunnett, deviation from control, 95% confidence interval

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

positive

Remarks:

at 250 mg/kg bw

Toxicity:

yes

Remarks:

>250 mg/kg bw

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

RESULTS OF DEFINITIVE STUDY
- Induction of micronuclei (for Micronucleus assay): significant increase at 250 mg/kg, no effects at lower doses
- Ratio of PCE/NCE (for Micronucleus assay): uneffected

Any other information on results incl. tables

Dose mg/kg	Animal No		MN per 2000 PCE		MN per 1000 NCE		Ratio of PCE/NCE
	m	f	m	f	m	f	m			f
Control	1	6	4	4	2	3	778	:	1000	1231	:	1000
	2	7	5	14	1	1	1082	:	1000	1210	:	1000
	3	8	16	8	3	1	975	:	1000	1161	:	1000
	4	9	16	9	1	1	1102	:	1000	1019	:	1000
	5	10	15	3	0	1	972	:	1000	1115	:	1000
2.5	11	16	14	7	1	0	972	:	1000	1199	:	1000
	12	17	3	12	1	2	952	:	1000	1148	:	1000
	13	18	9	6	2	2	1175	:	1000	1291	:	1000
	14	19	11	11	2	1	1023	:	1000	1087	:	1000
	15	20	7	6	1	1	868	:	1000	981	:	1000
25.0	21	26	10	6	1	0	914	:	1000	1060	:	1000
	22	27	6	14	0	0	1093	:	1000	1107	:	1000
	23	28	9	6	0	2	1168	:	1000	1115	:	1000
	24	29	9	5	2	0	1011	:	1000	977	:	1000
	25	30	11	15	1	1	1053	:	1000	1147	:	1000
250.0	31	36	24	23	1	0	781	:	1000	1133	:	1000
	32	37	23	25	0	0	823	:	1000	557	:	1000
	33	37	27	20	1	1	928	:	1000	778	:	1000
	34	39	28	19	2	1	100	:	1000	814	:	1000
	35	40	22	20	0	0	826	:	1000	856	:	1000
100.0 Cyclophosphamid	41	46	147	93	3	1	863	:	1000	758	:	1000
	42	47	152	107	1	1	511	:	1000	600	:	1000
	43	48	108	139	2	2	542	:	1000	586	:	1000
	44	49	105	136	1	2	567	:	1000	459	:	1000
	45	50	129	158	1	3	535	:	1000	629	:	1000

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): positive
Significant increase of micronucleated polychromatic erythrocytes at the highest dose level tested (250 mg/kg) in male an female mice.