Registration Dossier

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well documented publication which meets basic scientific principles

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1997

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Principles of method if other than guideline:
Method according to Schmid (1975) and McGregor (1980)
GLP compliance:
not specified
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): N-methyldiethanolamine
- Analytical purity: 99.8%

Test animals

Species:
mouse
Strain:
Swiss Webster
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: 6-8 weeks


Administration / exposure

Route of administration:
intraperitoneal
Duration of treatment / exposure:
single application
Frequency of treatment:
once
Post exposure period:
30, 48 and 72 hours
Doses / concentrations
Remarks:
Doses / Concentrations:
175, 350, 560 mg/kg bw
Basis:
nominal conc.
No. of animals per sex per dose:
5
Control animals:
yes, concurrent vehicle
Positive control(s):
triethylenemelamine
- Route of administration: i.p.
- Doses / concentrations: 0.3 mg/kg
- 30 h post dosing

Examinations

Tissues and cell types examined:
peripheral blood erythrocytes
Details of tissue and slide preparation:
CRITERIA FOR DOSE SELECTION:
based on pretest: about 80, 50 and 25 % of the LD50


DETAILS OF SLIDE PREPARATION:
Slides of blood smears were stained with Gurr's R-66 Giemsa diluted in phosphate buffer, coded and read without knowledge of treatment group to prevent bias.

METHOD OF ANALYSIS:
The polychromatic/normochromatic erythrocyte ratio for approximately 1000 total cells for each animal was calculated to provide an estimate of cytotoxicity.

Evaluation criteria:
A positive result was concluded if at least one statistical significant increase above vehicle control was an indication of a dose-related effect.
Statistics:
Data were compared for significant differences using the Fisher's Exact Test.

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls validity:
valid
Negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
There were no significant differences in the polychromatic erythrocyte to normochromatic erythrocyte ratios at any dosage. Furthermore, no significant increases in the incidence of micronucleated polychromatic erythrocyte were observed at any sampling time. Therefore, MDEA is not considered to be inducer of micronuclei under the condition of this in vivo test.

Any other information on results incl. tables

Induction of micronucleus in peripheral erythrocytes:

 Sex  Mean PCE/1000 NCE (±SD)                
   Water  TEM  MDEA (mg/kg)          
       175  350  560    
30 h postdosing              
  Male  52±24  36±8  55±17  64±11  70±12    
  Female  35±10  36±9  41±8  48±9  41±14    
48 h postdosing              
  Male  43±13    45±17  43±12  36±4    
  Female  31±6    34±18  32±12  38±4    
72 h postdosing              
  Male  39±7    38±12  36±14  32±14    
  Female  32±9    31±11  39±9  24±7    

 Sex  Mean MN-PCE/1000 NCE (±SD)                
   Water  TEM  MDEA (mg/kg)          
       175  350  560    
30 h postdosing              
  Male  5.4±3.2  42.0±8 b  4.8±2.4  6.6±2.9 4.8±3.5     
  Female  2.6±1.7  43±15 b  4.2±2.8  3.0±0.7  1.6±1.5    
48 h postdosing              
  Male  3.8±3.1   4.2±2.8   5.0±4.4  3.0±2.0    
  Female  2.4±1.5    3.8±2.4  2.2±1.3  2.6±2.7    
72 h postdosing              
  Male  5.0±2.0    2.6±2.1  7.0±5.6  2.7±1.2    
  Female  3.2±1.1   2.2±1.3   3.0±2.8  2.8±1.9    

There were no significant differences in the polychromatic erythrocyte to normochromatic erythrocyte ratios at any dosage. Furthermore, no significant increases in the incidence of micronucleated polychromatic erythrocyte were observed at any sampling time. Therefore, MDEA is not considered to be inducer of micronuclei under the condition of this in vivo test.

Applicant's summary and conclusion