Merginol 901

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1985-07-08 until 1985-08-01

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1985

Report date:

1985

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

no

GLP compliance:

yes

Type of assay:

other: micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

Oleic methyl ester, epoxidized, reaction products with glycerol

IUPAC Name:

Oleic methyl ester, epoxidized, reaction products with glycerol

Test material form:

liquid: viscous

Specific details on test material used for the study:

- Name of test material: LA 990
- Substance type: organic
- Physical state: viscous liquid, beige-coloured
- Lot/batch No.: 37-4-222
- Stability under test conditions: stable under test conditions
- Storage condition of test material: at room temperature

Test animals

Species:

mouse

Strain:

other: CWF 1

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Winkelmann, 4799 Borchen, FRG
- Age at study initiation: appox. 8 weeks
- Weight at study initiation: 17 -30 g
- Housing: Male mice individually in macrolon cages type I; female mice up to 4 animals per cage in macrolon cages type II.
- Diet: Altromin No. 1324, 10 mm pellet diameter, supplied from Altrogge Spezialfutter.
- Water: Drinking water
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature: 21°C
- Humidity: 30 - 70 %
- Photoperiod: 12 hours dark/ light cycle

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

- Vehicle: distilled water with carboxymethyl cellulose 2% and cremophore 0.5 %
- Justification for choice of vehicle: preparation of a suspension for adequate administration
- Amount of vehicle: 20 mL/kg

Frequency of treatment:

once

Post exposure period:

10000 mg/kg bw: 24, 48, and 72 h
5000 mg/kg bw: 24 h
1000 mg/kg bw: 24 h

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

Doses / concentrations 2

Dose / conc.:

5 000 mg/kg bw/day (actual dose received)

Doses / concentrations 3

Dose / conc.:

10 000 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

7 animals per sex per dose

Control animals:

yes, concurrent vehicle

Positive control(s):

Cyclophosphamid 10 mg/kg bw intraperitoneal (seven male and female animals)

Examinations

Tissues and cell types examined:

bone marrow cells

Details of tissue and slide preparation:

DETAILS OF SLIDE PREPARATION:
24, 48 and 72 h after the administration the animals were sacrificed with an overdose of carbonmonoxide. Bone marrow was extracted from the femur and prepared adequately. Three slides were prepared for each animal. The slides were air-dried at least overnight and then stained with Giemsa according to modification of Gollapudi and Kamra. The slides were fixed in 100 % methanol for 5 min., then rinsed twice in distilled water and thereafter stained in Giemsa solution. After air -drying the back side was cleaned, necessary with ethanol and then dipped for 3 min. in xylol.

METHOD OF ANALYSIS:
From the three slides prepared per animal, one slide was chosen and randomly scored. The slides of five male and five female animals per treatment group were scored microscopically at a magnification of 1000. The number of micronucleated cells was counted in 1000 polychromatic erythrocytes/ per animal. The ratio of polychromatic to normochromatic erythrocytes was determined by counting and differentiating the first 1000 erythrocytes at the same time. Averages and standard deviations were calculated after decoding the complete scoring results.

Evaluation criteria:

- A micronucleus test is considered acceptable if it meets the following criteria: The positive control substance induced a statistical significant increase in the frequency of micronucleated polychromatic erythrocytes - the incidence of micronuclei should reasonably fall within the historical control data range of the laboratory.
- A test item is considered positive in the micronucleus test if it induced a biologically as well as statistically significant increase (p < 0.05) in the frequency of micronuclei at any dose or at any sampling either in the male or in the female groups.
- A test substance is considered negative in the micronucleus test if none of the tested doses or sampling times showed a statistically significant (p < 0.05) increase in the incidence of micronuclei, neither in male nor in female groups.

Statistics:

Statistical analysis of data was performed by calculating the statistical significance versus negative controls with the aid of the tables of Kastenbaum and Bowman. The preceding criteria are not absolute and other factors may influence the final evaluation decision.

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

RESULTS OF DEFINITIVE STUDY
At the highest test item concentration of 10000 mg/kg bw, no effect on the numerical ratio between polychromatic and normchromatic erythrocytes was observed. Furthermore, the test item did not cause a significantly elevated number of micronucleated polychromatic erythrocytes when compared to the concurrent negative control. Thus the lower test item concentrations of 5000 and 1000 mg/kg bw were not microscopically evaluated. Besides the death of one animal in the 5000 mg/kg bw does group, not toxic effects were observed. The death of this animal could not be related to the test item exposure.