Registration Dossier

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
1995

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
GLP compliance:
yes
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Mono-n-butylamin-hydrochlorid 63%
- Physical state: Colorless liquid
- Lot/batch No.: LJ 20-92
- Other: Room temperature

Test animals

Species:
mouse
Strain:
NMRI
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River GmbH, WIGA, Sulzfeld, Germany
- Weight at study initiation: ca. 28 g
- Housing: groups of 5 in Makrolon cages
- Assigned to test groups randomly: yes, under following basis: computer program
- Diet: Standardized pelleted feed (Kliba Haltungsdiaet), ad libitum
- Water: tap water ad libitum
- Acclimation period: 1 week


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24 °C
- Humidity (%): 30-70 %
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
intraperitoneal
Vehicle:
- Vehicle(s)/solvent(s) used: water
Duration of treatment / exposure:
24 h and 48 h.
Frequency of treatment:
single intraperitoneal application
Post exposure period:
24 h and 48 h
Doses / concentrations
Remarks:
Doses / Concentrations:
0, 200, 400, 800 mg/kg bw in a volume of 10 ml/kg bw
Basis:
nominal in water
No. of animals per sex per dose:
5
Control animals:
yes, concurrent vehicle
Positive control(s):
cyclophosphamide; vincristine
- Route of administration: intraperitoneal
- Doses / concentrations: 20 mg/kg bw of cyclophosphamide or 0.15 mg/kg bw of vincristine

Examinations

Tissues and cell types examined:
Polychromatic erythrocytes from the bone marrow
Details of tissue and slide preparation:
CRITERIA FOR DOSE SELECTION: acute intraperitoneal toxicity pretests

DETAILS OF SLIDE PREPARATION:
The bone marrow was prepared according to the method described by SCHMID, W., Chemical Mutagens, Principles and Methods for their Detection, Volume 4, Plenum Press, New York (1976)

METHOD OF ANALYSIS: microscopic analysis

Evaluation criteria:
The following parameters were recorded:
-Number of polychromatic erythrocytes
-Number of polychromatic erythrocytes containing micronuclei
-Number of normochromatic erythrocytes
-Number of normochromatic erythrocytes containing micronuclei,
- Ratio of polychromatic to normochromatic erythrocytes
-Number of small micronuclei (d < D/4) and of large micronuclei (d > D/M) (d = diameter of micronucleus, D =cell diameter).
Statistics:
The statistical evaluation of the data was carried out using the program system MUKERN (BASF AG). A comparison of the dose group with the vehicle control was carried out using the Wilcoxon test for the hypothesis of equal medians.

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
yes
Remarks:
800 mg/kg bw: irregular respiration, abdominal position and salivation about 15 minutes after administration. 400 mg/kg bw or 200 mg/kg bw: irregular respiration only were observed.
Vehicle controls validity:
valid
Negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
RESULTS OF RANGE-FINDING STUDY
- Dose range: 800 - 1000 mg/kg bw
- Clinical signs of toxicity in test animals: irregular respiration, abdominal position, salivation and squatting posture and the general state of the animals was poor.


Any other information on results incl. tables

Summary of Micronucleus Test Results:

Dose: mg/kg bw Total No. PCE´s NCE´s/PCE´s

Micronuclei in PCE´s ()

Micronuclei in NCE´s ()

 
 0 (24 h) 10000 4252  1.8 1.2
 0 (48 h) 10000 4609  2.5 0.9
200 (24 h) 10000 4966 1.2  1.2
400 (24 h) 10000 3621  1.7 2.8
800 (24 h) 10000 4676 1.8 2.1
800 (48 h) 10000 4792  1.1 1.3  
20 mg/kg bw Cyclophosphamide (24 h) 5000 2109   22.6x 2.8  
0.15 mg/kg bw Vincristine (24 h) 5000 4828 91.2x  2.8  

x: p ≤ 0.01

After the single administration of the highest dose of 800 mg/kg body weight, 1.8 ‰ polychromatic erythrocytes containing micronuclei were found after 24 hours and 1.1 ‰ after 48 hours. In the two lower dose groups rates of micronuclei of about 1.7 ‰ (400 mg/kg group) and 1.2 ‰ (200 mg/kg group) were detected after a sacrifice interval of 24 hours in each case.

 

With 22.6 ‰ the positive control substance cyclophosphamide for clastogenicity, as expected, led to a clear increase in the number of polychromatic erythrocytes containing exclusively small micronuclei at a dose level of 20 mg/kg body weight. With 91.2 ‰ the positive control vincristine for spindle poison effects also led to a clearly enhanced number of micronuclei containing polychromatic erythrocytes with the expected amount of large micronuclei, i.e. 10.8 ‰.

 

The number of normochromatic erythrocytes containing micronuclei did not differ to any appreciable extent in the negative control or in the various dose groups at any of the sacrifice intervals. Thus, the test substance Mono-n-butylamin-hydrochlorid 63 % did not lead to any increase in the rate of micronuclei. The number of normochromatic or polychromatic erythrocytes containing small micronuclei (d < D/4) or large micronuclei (d > D/4) did not deviate from the solvent control value at any of the sacrifice intervals.

Thus, under experimental conditions chosen here, Mono-n-butylamin-hydrochlorid 63% does not have any clastogenic effect, and there were no indications of any impairment of chromosome distribution in the course of mitosis.

Applicant's summary and conclusion