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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline with acceptable restrictions

Data source

Reference
Reference Type:
publication
Title:
Evaluation of chromosomal aberrations in bone marrow of 1C3F1 mice.
Author:
Adler, I.D. & Ingwersen, I.
Year:
1989
Bibliographic source:
Mutat. Res. 224, 343-345

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 475 (Mammalian Bone Marrow Chromosome Aberration Test)
Principles of method if other than guideline:
The present experiment was conducted according to the test procedure described in Annex V of EEC Directive 79-831, Part B (1984).
GLP compliance:
not specified
Type of assay:
chromosome aberration assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Caprolactam

Test animals

Species:
mouse
Strain:
other: 1C3F1
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: 10-14 weeks
- Weight at study initiation: 25-28 g


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

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
- Vehicle(s)/solvent(s) used: water for test substance, corn oil for positive control
Details on exposure:
PREPARATION OF DOSING SOLUTIONS: Caprolactam (CAP) was dissolved in distilled water and orally applied by stomach intubation in a volume of 0.1 ml/10 g body weight.

Duration of treatment / exposure:
single administration
Frequency of treatment:
1
Post exposure period:
24-48 h
Doses / concentrations
Remarks:
Doses / Concentrations:
1000 mg/kg bw
Basis:
actual ingested
No. of animals per sex per dose:
5
Control animals:
yes, concurrent vehicle
Positive control(s):
benzo(a)pyrene
- Route of administration: gavage
- Doses / concentrations: 63 mg/kg bw

Examinations

Tissues and cell types examined:
bone marrow cells
Details of tissue and slide preparation:
TREATMENT AND SAMPLING TIMES:
Bone marrow of CAP-treated animals was sampled after 24, 30 and 48 h.
The sampling time for benzo(a)pyrene (BP)-treated animals was 30 h after treatment.
Each experimental group consisted of 5 treated males and 5 treated females plus 2 animals of each sex given distilled water. BP was tested with 5 males only. A total of 100 cells at mitotic metaphase per animal were scored microscopically. Mitotic indices were determined by counting the number of mitoses among 500 cells in a given field on each slide, i.e., a total of 1000 cells per animal.


METHOD OF ANALYSIS: The aberrations scored were of the chromatid or isochromatid type, i.e., gaps, breaks and fragments.


Evaluation criteria:
not reported

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls validity:
valid
Positive controls validity:
valid

Any other information on results incl. tables

 

Treatment

Interval

(h)

Numbers of cells scored

Number of cells with

Aberrant cells

(%±SE)a

Mitotic indexb

Gaps

Breaks

Exchanges

Water

-

1000

16

5

0

0.5±0.2

3.1

 

CAP

24

1000

20

3

0

0.3±0.2

2.4

30

1000

4

0

0

0.0±0.0

2.1*

48

1000

4

3

0

0.3±0.2

2.1*

BP

30

500

20

10

4

2.4±0.9**

2.8

aExcluding cells with only gaps

bPercent cells at mitosis (based on 1000 cells counted per animal)

* p<0.05, ** p<0.01

Applicant's summary and conclusion