N-methyl-N-vinylacetamide

Specific investigations: other studies

Administrative data

Endpoint:

specific investigations: other studies

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1993

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The genetic principle: loss of heterozygosity for the wild-type reporter gene w+, an event predominantly resulting from homologous interchromosomal mitotic recombination between the two X chromosomes of female genotypes.

GLP compliance:

no

Type of method:

in vivo

Endpoint addressed:

other: DNA modifications

Test material

Test material information

Constituent 1

Reference substance name:

N-methyl-N-vinylacetamide

EC Number:

221-698-5

EC Name:

N-methyl-N-vinylacetamide

Cas Number:

3195-78-6

Molecular formula:

C5H9NO

IUPAC Name:

N-ethenyl-N-methylacetamide

Test animals

Species:

other: Drosophila (Cross C-1: y (yellow) females X w (white) males

Details on test animals or test system and environmental conditions:

Strains y and w contain chromosomes from two laboratory stocks used when these mutants were isolated in induction experiments with N-ethyl-N-nitrosourea

Administration / exposure

Route of administration:

other: acute feeding and inhalation

Vehicle:

other: 200 µg/L enthanol (inhalation) or 3% ethanol, 1% Tween 80 (acute feeding)

Details on exposure:

Acute feeding:
Lavea were collected by washing them out of 58-72 h old mass cultures (20-30 pairs per bottle, 24 h egg-laying period) with an aqueous solution of 15% sucrose. The sucrose solution containing the larvae was filtered through nylon gauze, washed with 0.7% NaCl solution and 200-400 mg larvae was resuspended in 5 ml 0.7% NaCl solution in a test tube. To this solution the test agent, dissolved in a solvent, was added to yield the desired concentration. Seven minutes later a second aliquot of the test chemical was added. After 15 min of total exposure, the test chemical was removed by filtration on a nylon gauze, the larvae washed three times with 0.7% NaCl solution and placed in bottles on standard food. Addition of 0.5-1 ml NaCl solution was helpful to reach a more uniform distribution othe larvae over the surface.

Inhalation:
Flies (50 pairs per bottle) were put on a thin layer ( about 1 cm) of standard food in 600 ml bottles having screw caps and females were allowed to oviposit for 24 h. The parental flies were discarded, the culture kept at 25°C for antother 48 h and then 0.1 ml ethanol containing the test chemical was added to yield the desired doses. These treatment units were kept tightly sealed for 17 h and incubated at 25°C. Then the larvae were removed by using a 15% sucrose solution, washed and placed in bottles with standard food. Thus at the beginning of the inhalation treatment larvae were 28-52 h old (48-72 h old cultures).

Analytical verification of doses or concentrations:

no

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

1 000 ppm

Remarks:

inhalation

Doses / concentrations 2

Dose / conc.:

2 000 ppm

Remarks:

inhalation

Doses / concentrations 3

Dose / conc.:

40 other: mM

Remarks:

acute feeding

Doses / concentrations 4

Dose / conc.:

80 other: mM

Remarks:

acute feeding

Doses / concentrations 5

Dose / conc.:

160 other: mM

Remarks:

acute feeding

Details on study design:

Sample size:
500 - 750 eyes tested

Examinations

Examinations:

Microscopic analysis of eyes:
Newly hatched females was transfered to fresh medium and scored 1-5 days later. The scoring of etherized flies was carried out in a liquid consisting of 90 parts ethanolm 1 part Tween 80 and 9 parts water. The eyes of the adult females were inspected for mosaic light spots under a dossecting microscope at a magnification of 50-75 x. Spots separated from each other by at least four non-mutated ommatidia were counted as independent events.
Data analysis:
For data analysis, a distinction was made as follows:
small spots (size classes: 1-2 and 3-4)
large spots (all clones > 4 ommatidia)
total spots
For an indirect estimation of genotoxic effectiveness in eye disc cells, the frequency of clones per 10E4 cells was calculated according to the formula f = 2 nm/ NC, where m= mean clone size, n = number or mosaic spots, 2 = correction factor, C is 800 (ommatidia) and N= number of eyes analysed.
Test response were classified into three categories:
Positive ++
A strong recombinagenic response and a dose-response relation was found.
Weakly positive +w
The clone frequency was significantly enhanced compared with both concomitant and pooled controls, but no more than about a doubling of the spontaneous spot frequency is associated with signs of toxicity meaning that a dose-response relationship could not be established.
Negative -
No effect under all conditions of test

Positive control:

no data

Results and discussion

Details on results:

Please refer to any other information on results incl. tables

Any other information on results incl. tables

Results of the w/w+ eye mosaic test after inhalative treatment and acute feeding

Inhalation
concentration	Eyes tested	Spots per 100 eyes			Average clone size	Clones per 10E4 cells	Activity
		S	L	T
0 ppm	500	2.80	0.40	3.2	3.4	2.7
1000 ppm	750	2.00	0.67	2.7	2.9	1.9	-
2000 ppm	750^#	3.07	0.93	4.0	5.1	5.1	-
Acute feeding
concentration	Eyes tested	Spots per 100 eyes			Average clone size	Clones per 10E4 cells	Activity
		S	L	T
0 mM	500	3.60	0.40	4.0	2.3	2.3
40 mM	500	5.20	0.80	6.0	3.6	5.4	i
80 mM	500	7.00	0.80	7.8	3.3	6.4	+w
160 mM	500	5.40	1.00	6.4	3.3	5.3	i

^#indicated reduced survival in relation to the control

S small spots, clone size 1-4 ommatidia

L large spots, clone size > 4 ommatidia

T, total spots

- inactive (for more details please refer to chapter examinations)

i inconclusive (for more details please refer to chapter examinations)

+w weakly positive (for more details please refer to chapter examinations)

Results and conclusion

Under the conditions of the recent study inhalative treatment indicated no increased activity compared to the control group. Only at a concentration of 80 mM a weakly positive response were indicated after acute feeding with the test item. However, the result was associated with signs of toxicity meaning that a dose-response relationship could not be established and thus, in conclusion the test item was considered to have a relatively low DNA reactivity.