Dinitrotoluene

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian cell study: DNA damage and/or repair

Remarks:

Type of genotoxicity: DNA damage and/or repair

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Reliability as cited in OECD SIDS Dinitrotoluene (isomers mixture) CAS No.: 25321-14-6, 2004. Guideline study without detailed documentation

Data source

Reference

Reference Type:

publication

Title:

Measurement of unscheduled DNA synthesis and S-Phase synthesis in rodenthepatocytes following in vivo treatment: Testing of 24 compounds.

Author:

Mirsalis, J.C. et al.

Year:

1989

Bibliographic source:

Environ Molec Mutagen 14, 155-164

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 486 (Unscheduled DNA Synthesis (UDS) Test with Mammalian Liver Cells in vivo)

Deviations:

yes

Remarks:

only pooled data shown; composition of test substance not described in detail

GLP compliance:

no

Type of assay:

unscheduled DNA synthesis

Test material

Test material information

Constituent 1

Reference substance name:

Dinitrotoluene

EC Number:

246-836-1

EC Name:

Dinitrotoluene

Cas Number:

25321-14-6

Molecular formula:

C7H6N2O4

IUPAC Name:

Reaction mass of 1-methyl-2,4-dinitrobenzene and 2-methyl-1,3-dinitrobenzene

Details on test material:

- Name of test material (as cited in study report): technical-grade dinitrotoluene
- Isomers composition: DNT; 76.5% 2,4-DNT, 18.8% 2,6-DNT, 4.7% other isomers

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Simonsen Laboratories, Gilroy, CA and Hilltop Laboratory Animals, Chatsworth, CA
- Weight at study initiation: 180 - 300 g
- Housing: Three per cage in polypropylene cages with hardwood-chip bedding
- Diet (e.g. ad libitum): Purina Rodent Chow #5001 (Ralston Purina Co., St. Louis); ad libitum
- Water (e.g. ad libitum): deionized, 0.5 µm charcoal filtered tap water; ad libitum


ENVIRONMENTAL CONDITIONS
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: corn oil; no data on the solvents of positive controls

Duration of treatment / exposure:

single bolus

Frequency of treatment:

once

Post exposure period:

2 and 12 hours

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 35, 125 and 250 mg/kg bw
Basis:
actual ingested

No. of animals per sex per dose:

3; only two animals at 250 mg/kg bw

Control animals:

yes, concurrent vehicle

Positive control(s):

2-acetylaminofluorene; dimethylnitrosamine
- Route of administration: oral: gavage
- Doses / concentrations: 2-AAF: 50 mg/kg bw (12 h); DMN: 10 mg/kg bw (2 h)

Examinations

Tissues and cell types examined:

primary rat hepatocyte cultures

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION: Doses were selected based approximately on the oral LD50 of the compound and were generally selected as 80%, 40%, and 10% of the LD50. The acute LD50 was never exceeded.


TREATMENT AND SAMPLING TIMES ( in addition to information in specific fields): 2 and 12 h


DETAILS OF SLIDE PREPARATION: Cells were allowed to attach to coverslips.


METHOD OF ANALYSIS: 50 morphologically unaltered cells were counted per slide. Three slides were scored for each animal or concentration for a total of 150 cells per animal. UDS was measured by quantitative autoradiography as net grains (NG) per nucleus. The percentage of cells undergoing repair (%IR) was determined as the percent of those cells exhibiting 5 or more NG.


OTHER:

Evaluation criteria:

Compounds were considered negative if the NG of all dose groups was a negative number and the %IR was less than 10%. Compounds were considered positive if the average NG of any dose group exceeded 0 NG. Compounds with negative NG values, but %IR values greater than 10% were considered equivocal.

Statistics:

The mean and the standard error of the mean were calculated.

Results and discussion

Test results

Sex:

male

Genotoxicity:

positive

Toxicity:

not specified

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Any other information on results incl. tables

	Dose [mg/kg]	Time [h]	NG	n	%IR
	0 (corn oil)	2	-6.4 ± 2.9	2	1 ± 0
	0 (corn oil)	12	-5.6 ± 0.4	52	2 ± 0
DNT	35	2	-11.2 ± 1.7	3	4 ± 0
		12	-5.5 ± 1.2	3	3 ± 1
	125	12	17.4 ± 3.1	3	77 ± 7
	250	12	31.0 ± 7.8	2	89 ± 5
2-AAF	50	12	22.9 ± 1.7	52	85 ± 2
DMN	10	2	41.8 ± 3.4	31	90 ± 2

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): positive