1-chloro-N,N-diethyl-1,1-diphenyl-1-(phenylmethyl)phosphoramine

Genetic toxicity: in vivo

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

Study period:

From April 1990 to september 1990

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study performed according to a standardized method and in compliance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD guidelines, section 4, subpart 474, Paris 1981

GLP compliance:

yes

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

GM102E

IUPAC Name:

GM102E

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

white powder
batch 8724

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Company of Calco (Como), Italy
- Weight at the time of use: 91 - 120g
- Assigned to test groups randomly: no formal randomization was adopted.
- Fasting period before study:
- Housing: makrolon cages (42x26x15 cm), each fitted with a stainless steel cover-feed rack. Dust-free poplar/fir chips, heat processed for resin removal, were used for bedding.
- Diet (e.g. ad libitum): on a dry matter basis (moisture 12%), the diet contained crude proteins (18.5%), crude fat (3%), crude fiber (6%) and ash (7%). This was supplemented by vitamins and trace elements.
- Water (e.g. ad libitum): municipal filtered water was distributed ad libitum by a means of an automatic wetring valve system.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/-2°C
- Humidity (%): 60 +/-20%
- Air changes (per hr): 13 air changes per hour filtered on HEPA 98%
- Photoperiod (hrs dark / hrs light): circadian cycle of 12 hours of light

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

deionized water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
202 mg of the test article were dissolved in water to obtain the concentration of 5 mg/ml
Mitocyn C was dissolved in water to obtain the concentration of 0.8 mg/ml.

Frequency of treatment:

Single administration.

Post exposure period:

Sacrifice time: 18, 42, 66 hours

Doses / concentrations

Remarks:

Doses / Concentrations:
50 mg/kg
Basis:
nominal in water

No. of animals per sex per dose:

Male: 15; Female: 15

Control animals:

yes, concurrent vehicle

Positive control(s):

Mitomycin C
- Route of administration: intraperitoneal
- Doses / concentrations: 8 mg/kg

Examinations

Tissues and cell types examined:

Bone marrow cells were examined.

Details of tissue and slide preparation:

The bone marrow was taken from femur of each rat immediately after the sacrifice of animals. The bone marrow was suspended and carefully washed in 3 ml of fetal bovine serum.
The suspension was centrifugated at 1000xg for 10 min. The supernatant was carefully taken off and the cell sediment smeared on microscope slides. Two slides per animal were prepared.

Slides preparation:
At least 20 hours later, the smears were stained as follows:
1. immersion in May Gruenwald solution for 3 min
2. washing in 1.779 g/l NaNH3PO4.4H2O (buffer)
3. immersion in May Gruenwald solution diluted 1:1 with buffer for 2 min, then rinsed twice with buffer
4. immersion in Giemsa solution diluted 1:6 with buffer for 7.5 min
5. rinsing with buffer and careful drying with filter paper.

The stained slides were coded and read at the microscope (1250x). For each animal, 2000 polychromatic erythrocytes were counted and scored for micronucleated cells.
Furthermore, the ratio of polychromatic to normochromatic erythrocytes was calculated on one slide per animal, by counting a total of 1000 polychromatic erythrocytes (PE).

Statistics:

Comparison of the frequency among groups was performed with a non-parametric method (Mann Whitney).

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

not examined

Positive controls validity:

valid

Additional information on results:

There is no significant difference between the micronucleus frequency in the treated group in comparison with the control group at any sampling time.
The group of animals treated with the positive control, Mitomycin C, showed a statistically increased frequency of micronucleated cells in comparison with the control group.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): negative
The GM102E, administered by oral route to male and female rats at the dose of 50 mg/kg, did not induce any statistically significant increase in the frequency of micronucleated cells in the bone marrow after 18, 42 and 66 hours from the administration.

Executive summary:

A bone marrow micronucleus assay was conducted in Sprague-Dawley rats according to the micronucleus test in order to assess the in vivo genotoxicity of GM102E. The study was conducted to a standard OECD guideline and in compliance with good laboratory practices. Animals (15 males and females per test substance dose and negative control) were treated by gavage with the test substance at 50 mg/kg bw in deionized water in a single administration. The positive control, Mitomycin C, was administered intraperitoneally to 5 males and 5 female.

Bone marrow cells were harvested at 18-hour, 42 -hour and 66 -hour post-treatment. There is no significant difference between the micronucleus frequency in the treated group in comparison with the control group at any sampling time. The group of animals treated with the positive control, Mitomycin C, showed a statistically increased frequency of micronucleated cells in comparison with the control group. Under the conditions of the in vivo test, the registered substance showed no evidence of causing chromosome damage or bone marrow cell toxicity.