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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian germ cell study: cytogenicity / chromosome aberration
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: comparable to guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988

Materials and methods

Principles of method if other than guideline:
other: in vivo bone marrow cytogenetics rat metaphase analysis
GLP compliance:
yes
Type of assay:
chromosome aberration assay

Test material

Constituent 1
Chemical structure
Reference substance name:
N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine
EC Number:
212-344-0
EC Name:
N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine
Cas Number:
793-24-8
Molecular formula:
C18H24N2
IUPAC Name:
N-(1,3-dimethylbutyl)-N'-phenylbenzene-1,4-diamine
Details on test material:
Santoflex 13, lot # KJ09-165

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female

Administration / exposure

Route of administration:
oral: gavage
Duration of treatment / exposure:
once
Frequency of treatment:
once
Post exposure period:
6, 18 and 30 h
Doses / concentrations
Remarks:
Doses / Concentrations:
preliminary study: 900, 1300, 1790 mg/kg bw, main experiment: 1000 mg/kg bw
Basis:

No. of animals per sex per dose:
pre-test: 1 per dose and sex, main test: 5 per dose and sex and sampling time
Control animals:
yes, concurrent vehicle

Examinations

Tissues and cell types examined:
bone marrow from femur

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
yes
Vehicle controls validity:
valid
Negative controls validity:
not specified
Positive controls validity:
valid

Any other information on results incl. tables

Range-finding experiment:

Clinical signs and necropsy

1790 mg/kg:

Male: diarrhea, decreased body tone and activity, tremor, abnormal gait and stance, piloerection and redish-brown discoloration around the nasal and oral regions, net weight loss 10 grams, dead by day 2

Necropsy: hemorrhagic areas on the thymus and stomach lining, stomach and intestines were distended and fluid filled

Female: piloerection, decreased body tone and decreased activity, net weight loss 11 grams, dead by day 3

Necropsy: dark red lungs and adrenals, and distended fluid-filled stomach and intestines

1300 mg/kg bw:

Male and female: prostrate and moribund by day 1, by day 2 both rats were dead

necropsy: grossly distended stomach filled with reddish discolored material

900 mg/kg:

Male/female: decreased body tone, abnormal gait and stance, piloerection and diarrhea on day 1. Male also exhibited decreased activity; on day day, the male exhibited poor grooming and decreased body tone, the female exhibited an abnormal gait and stance. no signs were observed on day 7 prior to study termination.

Main experiment

Clinical signs 1000 mg/kg

No pharmacotoxic signs of treatment were observed in animals administered Santoflex 13 immediately after dosing. Prior to colchicine, however, signs observed in all groups treated with Santoflex 13 were as follows:

6 Hour Group: (observed approximately 4 hours after dosing); all rats had abnormal gait and decreased body tone with most of the rats also exhibiting decreased activity and abnormal stance. One male and one female exhibited piloerection and one male had body drop (skeletal muscle weakness demonstrated by lowered body position)

18 Hour Group (observed approximately 16 hours after dosing); all rats had abnormal gait and stance and most of the rats also had decreased body tone and activity. Two males had diarrhea and one female had lacrimation and a yellow discoloration at the anal-genital region. Two females also exhibited tremors and piloerection at this time.

30 Hour Group (observed approximately 28 hours after dosing); all rats had diarrhea and decreased body tone, with most of the rats also exhibiting piloerection, decreased activity and/or abnormal gait and stance. Signs observed in three or less animals included body drop, lacrimation, ataxia, tremors and poor grooming around the oral, nasal region.

No pharmacotoxic signs were observed in rats administered the vehicle or positive controls with the exception of one male in the 6 hour corn oil group which exhibited diarrhea prior to colchicine administration.

Summary of Metaphases Scored:

A total of 500 metaphases/group (50/rat) were analyzed in each group, except for the CP group in which only a total of 435

metaphases were analyzed.

Proportion of Cells with Aberrations:

The proportion of cells with one or more aberrations (1 aberration or greater) was analyzed by Chi-square analysis by group comparing the number of cells with aberrations versus the number of normal cells. Each time of sacrifice was analyzed separately and groups within each sacrifice time were compared individually to the vehicle control. Cells with gaps only were not considered aberrant for this analysis. A statistically significant increase (p 0.01) was detected with the positive control CP group at the 18 hour sacrifice. No other significant differences were noted.

Analysis of Aberrations per Cell:

The mean number of aberrations per cell per animal were analyzed for statistically significant increases by a one way

ANOVA for each time interval. Data reflect the total number of aberrations seen in all cells scored per group. No statistically significant differences (p 0.05 or p 0.01) from the vehicle controls were detected by this analysis in animals treated with Santoflex 13.

Santoflex 13 treated groups were also analyzed by one way ANOVA for time related differences in aberrations/cell/animal when compared to the vehicle control groups. No statistically significant differences were observed.

Animals treated with CP gave a statistically significant (p 0.01) increase in the number of aberrations.

All rats dosed with Santoflex 13 (1000 mg/kg) exhibited from mild to severe pharmacotoxic signs at all time intervals evaluated. These observations suggest that Santoflex 13 was tested near the maximum tolerated dose. Statistical analysis of the data indicated that Santoflex 13 (1000 mg/kg) did not produce significant increases in the number of aberrations or in the

number of aberrant metaphases at any of the three sacrifice times evaluated.

The authors concluded that Santoflex 13 (1000 mg/kg) was negative in its ability to induce structural chromosomal aberrations to the hemopoietic cells of the rat bone marrow under the experimental conditions of this assay.

Applicant's summary and conclusion