2-methylbut-3-en-2-ol

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

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:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

2-methylbut-3-en-2-ol

EC Number:

204-068-4

EC Name:

2-methylbut-3-en-2-ol

Cas Number:

115-18-4

Molecular formula:

C5H10O

IUPAC Name:

2-methylbut-3-en-2-ol

Details on test material:

- Name of test material (as cited in study report): 2-methylbut-3-en-2-ol
- CAS No.: 115-18-4
- Batch No.: Abl. Nr. 79-1089
- Purity: 97.9 %
- Physical state: Colourless liquid
- Storage condition of test material: +4°C to +6°C

Test animals

Species:

mouse

Strain:

NMRI

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River GmbH, WIGA, D-W8741 Sulzfeld, FRG
- Weight at study initiation: mean ca. 27 g
- Assigned to test groups randomly:yes, under following basis: according to a randomization plan prepared with an appropriate computer program
- Housing: For the duration of about one week the animals were housed in Makrolon cages, type M III, in groups of 5; before the start of the treatment
the animals were transferred to Makrolon cages, type M I, and housed individually separately according to sex
- Diet: Standardized pelleted feed (Kliba Haltungsdiaet, Klingentalmuehle AG, CH-4303 Kaiseraugst, Switzerland); ad libitum
- Water: ad libitum


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

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: aqua dest.
- Amount of vehicle (if gavage or dermal): 10 mL/kg bw

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
All test substance formulations were prepared immediately before administration.
The amount of substance or volume to be administered was related to the specific weight of the individual animals on the day of the experiment.

Duration of treatment / exposure:

16 h (high dose only), 24 h (all treatments), 48 h (high dose only)

Frequency of treatment:

once

Post exposure period:

16, 24, 48 h

Doses / concentrations

Remarks:

Doses / Concentrations:
500, 1000 and 1500 mg/kg bw
Basis:
nominal conc.

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Positive control(s):

Cyclophosphamide
- Route of administration: oral
- Doses / concentrations: 20 mg/kg bw

Vincristine
- Route of administration: intraperitoneal injection
- Doses / concentrations: 0.15 mg/kg bw

Examinations

Tissues and cell types examined:

bone marrow of femora

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION:
In a pretest, mortalitiy was observed down to a dose of 1750 mg/kg body weight whereas 1500 mg/kg body weight was survived by all animals. Therefore, a dose of 1500 mg/kg body weight was selected as the highest dose in the present cytogenetic study. 1000 mg/kg and 500 mg/kg body weight were administered as further doses.

TREATMENT AND SAMPLING TIMES (in addition to information in specific fields):
The animals of the negative control were sacrificed 24 hours after administration of the solvent. The control animals were treated at different times so that it was always possible to prepare control animals simultaneously for all the different sacrifice intervals of the test animals.

DETAILS OF SLIDE PREPARATION:
The two femora were prepared from the animals, and all soft tissues were removed. After cutting off the epiphyses, the bone marrow was flushed out of the diaphysis into a centrifuge tube using a cannula filled with fetal calf serum which was at 37°C (about 2 ml/ femur). The suspension was mixed thoroughly with a pipette, centrifuged at 1500 rpm for 5 minutes, the supernatant was removed except for a few drops, and the precipitate was resuspended. 1 drop of this suspension was dropped onto clean microscopic slides, using a Pasteur pipette. Smears were prepared using slides with ground edges, the preparations were dried in the air and subsequently stained.
Staining: The slides were stained in eosin and methylene blue solution for 5 minutes, rinsed in aqua dest . and then placed in fresh aqua dest. for 2 or 3 minutes. They were finally stained in Giemsa solution for 12 minutes. After being rinsed twice in aqua dest. and clarified in xylene, the preparations were embedded in Corbit-Balsam.

METHOD OF ANALYSIS:
In general, 1000 polychromatic erythrocytes from each of the male and female animals of every test group are evaluated and investigated for micronuclei by microscopic evaluation.

Statistics:

A statistical evaluation was not necessary to perform. The number of polychromatic micronucleated erythrocytes after test substance treatment was nearly the range of the actual control value and within the historical values.

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

yes

Remarks:

irregular respiration, staggering, piloerection in all treatment groups

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

RESULTS OF RANGE-FINDING STUDY
- Clinical signs of toxicity in test animals: Mortality was observed down to a dose of 1750 mg/kg body weight whereas 1500 mg/kg body weight was survived by all animals.

RESULTS OF DEFINITIVE STUDY
- Clinical signs of toxicity in test animals:
1500 mg/kg and 1000 mg/kg groups:
<15 minutes: irregular respiration, staggering, piloerection, in few cases abdominal position
30 min. up to 4 hours: abdominal position, narcotic like stage, shallow respiration, poor general state
1st day after administration: piloerection, in few cases apathy
2nd day after administration: in few cases piloerection

500 mg/kg group:
< 15 minutes: irregular respiration, piloerection
15 min. up to 4 hours: irregular respiration, piloerection, staggering, squatting posture
1st day after treatment: no signs or symptoms

- Ratio of PCE/NCE (for Micronucleus assay): the ratio of polychromatic to normochromatic erythrocytes was always in the same range as that of the control values in all dose groups

Any other information on results incl. tables

Results:

Test group	Interval: 16 h
	Polychromatic erythrocytes	Normocytes / total amount polychromatic erythrocytes	Cells with micronuclei (‰)
Dose (mg/kg bw)			polychromatic	normochromatic
1500	10000	3565	2.0	1.4
Test group	Interval: 24 h
	Polychromatic erythrocytes	Normocytes / total amount polychromatic erythrocytes	Cells with micronuclei (‰)
Dose (mg/kg bw)			polychromatic	normochromatic
vehicle control	10000	3426	2.7	0.88
1500	10000	4945	2.7	1.82
1000	10000	4901	2	3.06
500	10000	5240	2	1.15
20; cyclophosphamide	5000	2834	10.6	2.12
0.15; vincristine	5000	3932	77.8	4.07
Test group	Interval: 48 h
	Polychromatic erythrocytes	Normocytes / total amount polychromatic erythrocytes	Cells with micronuclei (‰)
Dose (mg/kg bw)			polychromatic	normochromatic
1500	10000	3124	3.1	1.92

Test substance preparation analysis:

Depending on the dose, about 90 - 97% of the theoretical values could be determined analytically.