2-methylbut-3-en-2-ol

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

04 Feb 1991 to 18 Mar 1991 (experimental phase)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Version / remarks:

adopted 1981

Deviations:

no

GLP compliance:

yes

Limit test:

no

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-
- Physical state: colourless liquid
- Batch No.: 79-1089 from 26 Oct 1989
- Purity : 97.9 %
- Storage conditions: Room temperature

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Dr. Karl Thomae GmbH, Biberach/Riss, D
- Age at study initiation: 42 days at the start of application
- Weight at study initiation: mean 187 g (males), 161 g (females)
- Housing: singly in type DK III stainless steel wire cages from Becker & Co., Castrop-Rauxel, D (floor area about 800 cm2)
- Diet (e.g. ad libitum): Kliba rats/mice/ hamsters maintenance diet, "A" 343 meal, Klingentalmuehle AG, Kaiseraugst, Switzerland; ad libitum
- Water (e.g. ad libitum): drinking water; ad libitum
- Acclimation period: 10 days


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

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

olive oil

Remarks:

DAB 9

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
The doses were prepared daily. The test substance was weighed and diluted to the appropriate volume with olive oil DAB 9. The doses were dissolved using a magnetic stirring apparatus. The doses were administered using syringes (3 cc Syringe; Fa. Becton Dickinson & Co., USA)

VEHICLE
- Concentration in vehicle: 0.6, 3, 15 g/100ml
- Amount of vehicle (if gavage): 5 mL /kg bw

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Gas chromatography was used to determine the content of 2-Methylbuten-3-ol-2 of the undiluted test substance and of the doses. Hydrogen-nuclear magnetic resonance confirmed the identity of the test substance.

Duration of treatment / exposure:

4 weeks

Frequency of treatment:

5 times per week

Doses / concentrations

Remarks:

Doses / Concentrations:
30, 150 and 750 mg/kg body weight (Analytical checks of the concentrations confirmed that the concentrations were within an acceptable range (93 - 103% of the target concentration).
Basis:
actual ingested

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The doses for this study were chosen on the basis of previous investigations. In the first pretest, 2-methylbut-3-en-2-ol was administered in olive oil 11 times by gavage to each 3 male and 3 female Wistar rats at doses of 100 and 500 mg/kg body weight. A group of 3 male and 3 female animals served as vehicle control and received olive oil only. In order to find a dose with clear and persistent findings, a second pretest, 2-methylbut-3-en-2-ol was administered in olive oil at doses of 15 and 1.000 mg/kg body weight. The test substance was administered by gavage 11 times each to 3 male and 3 female Wistar rats. Vehicle control was a group each of 3 males and 3 females which received DAB 9 olive oil only. Detailed results were described under “Additional details on results”.

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: The general state of health of the animals was checked twice a day (Monday to Friday) and once a day (Saturdays, Sundays and public holidays). Furthermore the animals were checked for the appearance of clinical signs before and after each test substance administration

BODY WEIGHT: Yes
- Time schedule for examinations: before the start of the administration period in order to randomize the animals. During the conduct of the study, the body weight was determined on day 0 (start of administration period) and thereafter in weekly intervals

FOOD CONSUMPTION:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: 28 days after the beginning of administration period
- Anaesthetic used for blood collection: No
- Animals fasted: No
- How many animals: all surviving animals per test group and sex
- Parameters checked in table were examined: leukocytes, erythrocytes, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelets, differential blood count, thromboplastin time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: 28 days after the beginning of administration period
- Animals fasted: No
- How many animals: all surviving animals per test group and sex
- Parameters checked in table were examined: alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, serum-glutamyltransferase, sodium, potassium, chloride, inorganic phosphate, calcium, urea, creatinine, glucose, total bilirubin, total protein, albumin, globulins, triglycerides, cholesterol, magnesium

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
Organ weights: liver, kidneys, adrenal glands, thymus, spleen, and testes of all animals.
Fixed in 4% formaldehyde: liver, kidneys, spleen, adrenal glands, heart, thymus, brain, sciatic nerve, mandibular salivary glands, sublingual salivary glands, stomach, mesenteric lymph nodes, testes, ovaries and gross lesions
HISTOPATHOLOGY: Yes
Control and high dose group: liver, kidneys, spleen, adrenal glands, heart, thymus, brain, sciatic nerve, mandibular salivary glands, sublingual salivary glands
All treatment groups: gross lesions

Statistics:

Food consumption, body weight and body weight change, clinical chemistry and hematology (except differential blood count):
KRUSKAL-WALLIS h-test (Post test: MANN-WHITNEY U-test)
Terminal body weight, absolute and relative organ weights:
KRUSKAL-WALLIS h-test (Post test: WILCOXON-Test )

Results and discussion

Results of examinations

Details on results:

CLINICAL SIGNS AND MORTALITY
During the conduct of the study one female (750 mg/kg body .weight group) died intercurrently. However, this was attributable to gavage error and can therefore not be related to the test substance administration.

750 mg/kg bw:
- Ataxia was found in all male and female rats from the first test substance administration onward. One female rat of the high dose group showed lateral position and apathy after the 4th administration and died during the afternoon. Further clinical signs observed were piloerection in 4 females of the 750 mg/kg body weight group. In a few female animals lateral position, apathy and salivation occurred during the conduct of the study.
The clinical signs were observable after administration of the test substance throughout the working day; however, by the morning of the next day they were found to be reversible and reappeared only after a renewed substance administration
150 and 30 mg/kg bw: No clinical symptoms were observed

BODY WEIGHT AND WEIGHT GAIN
The body weight/body weight gain of the male and female rats of all dose groups corresponded to the values of the vehicle control group. The significant increased body weight gain on day 28 in male rats of test group 2 (150 mg/kg body weight) was assessed as being incidental.

FOOD CONSUMPTION
When compared with the untreated controls, the male and female rats of all dose groups showed no substance related differences regarding the amount of food consumed daily.

HAEMATOLOGY
No substance-related changes were observed in the hematological examinations of both sexes. No substance-related changes were observed in the
clotting analyses of both sexes.

CLINICAL CHEMISTRY
No substance-related changes were observed in the enzyme activities of both sexes.
In the highest dose group (750 mg/kg body weight) of both sexes the chloride concentrations in the serum were statistically significantly decreased when compared with the control. Moreover, in the serum of the high-dose females decreased potassium levels and in the serum of the males of test group 3 (750 mg/kg body weight) increased magnesium concentrations were detected. Although these findings are difficult to assign to a specific toxic effect, the changes in the electrolyte status are considered to be treatment-related.
At the end of the administration period statistically significantly increased cholesterol concentrations were observed in the peripheral blood of both sexes in the highest dose group. Furthermore, in the mid- and high-dose males the triglyceride levels were statistically significantly decreased compared to the control. The changes in cholesterol and triglyceride concentrations in the serum of the high-dose animals are assessed to be substance-related and are probably caused by a slight disturbance of lipid metabolism. However, the decreased triglyceride content in the serum of test group 2 (150 mg/kg body weight) males is not considered to be associated with the administration of the test article, since this finding is in the range of biological variation and is observed in one sex only.

PATHOLOGY
No substance-related changes were observed. In males of the 150 mg/kg bw group, the absolute liver weights were increased and the relative testes weights were decreased. Since no dose response relationship was evident, these effects were considered as not relevant. In females of the 750 mg/kg bw group, the mean absolute and relative liver weight was increased, but due to a incidental death the statistical power for a test was too weak; additionally, this effect was not supported by histopathological findings. Therefore, this result was considered as not relevant.
No morphological changes were seen in the brain or peripheral nerves. Thus, the clinical symptoms observed are most probably due to pharmacological or local irritating effects of the test substance but not due to permanent morphological alterations of the nervous system.

Effect levels

Dose descriptor:

NOAEL

Remarks:

systemic

Effect level:

150 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Clinical signs (reversible within one day), effects on blood chemistry and changes in the electrolyte status seen at 750 mg/kg bw/d

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

FIRST PRETEST
500 mg/kg bw: Lethargy and atactic gait were observed in the first week of the study, each time some hours after administration by gavage. Increased absolute and relative kidney weights were observed in males and decreased absolute and relative thymus weights in females.
100 mg/kg bw: Decreased absolute and relative thymus weights were observed in the females

SECOND PRETEST
1000 mg/kg bw: One female died after 3 administrations by gavage. Atactic gait, lethargy, piloerection and lateral position were observed in the males, each time after administration, but not on the next morning before the test substance administration. Lethargy and lateral position were observed in all 3 females, each time after administration. In addition, two rats showed atactic gait, one rat salivation and one rat laboured respiration. However, all these findings were reversible and no longer seen on the next morning before administration. The females showed pilorection and anogenital and lower abdominal regions smeared with urine, both after administration by gavage and also on the next morning before administration.
15 mg/kg bw: No clinical findings