2,2'-bipyridyl

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Data source

Reference

Reference Type:

publication

Title:

Acute and subacute toxicity in Sherman strain rats exposed to 4,4'- and 2,2'-dipyridyl

Author:

Groce DF, Kimbrough RD

Year:

1982

Bibliographic source:

J Toxicol Environ Health. 1982, 10(3):363-72;

Materials and methods

Principles of method if other than guideline:

Male and female rats received the test item as 2 % solution in 20 % ethanol by gavage. Four groups of 10 adult male or female Sherman rats were used per dose group. The control groups received the 20 % ethanol vehicle only. Two weeks after administration, survivors were killed, selected tissues were removed, fixed in formaldehyde and examined microscopically after H&E staining. LD50 values were calculated by the method of Litchfield & Wilcoxon.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-bipyridyl

EC Number:

206-674-4

EC Name:

2,2'-bipyridyl

Cas Number:

366-18-7

Molecular formula:

C10H8N2

IUPAC Name:

2,2'-bipyridine

Details on test material:

- Name of test material (as cited in study report): 2,2'-bipyridyl

Test animals

Species:

rat

Strain:

Sherman

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: U.S. Department of Health and Human Services, Center for Disease Control
- Fasting period before study: 24 h
- Housing: individually
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): controlled
- Humidity (%): controlled
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

ethanol

Remarks:

20%

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 2 %

Doses:

75, 120 and 150 mg/kg bw

No. of animals per sex per dose:

10 animals per sex per dose group

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, histopathology

Statistics:

The LD50 was calculated by the method of Litchfield and Wilcoxon (J Pharmacol Exp Ther. 1949, 96:99 -113)

Results and discussion

Effect levels

Effect levels 1

Sex:

male

Dose descriptor:

LD50

Effect level:

100 mg/kg bw

Based on:

test mat.

95% CL:

>= 89 - <= 112

Effect levels 2

Sex:

female

Dose descriptor:

LD50

Effect level:

107 mg/kg bw

Based on:

test mat.

95% CL:

>= 101 - <= 113

Effect levels 3

Sex:

male/female

Dose descriptor:

LD0

Effect level:

75 mg/kg bw

Based on:

test mat.

Effect levels 4

Sex:

male

Dose descriptor:

LD100

Effect level:

150 mg/kg bw

Based on:

test mat.

Mortality:

The acute oral LD50 values of 2,2'-bipyridine were 100 mg/kg bw in male and 107 mg/kg bw in female rats.
75 mg/kg bw had no effect on male or female rats.
At 150 mg/kg bw there was 100% mortality in males, and 120 mg/kg bw caused 80% mortality in female rats.

Clinical signs:

other: Clinical signs included immediate subdued behaviour, loss of muscle coordination, red urine, and tremors. Convulsions were observed immediately before death which occurred 1 or 2 d after dosing.

Gross pathology:

Autopsies of rats that died from acute doses of 2,2'-dipyridyl revealed massive pulmonary hemorrhage. Microscopic lung changes included pulmonary edema, intra-alveolar hemorrhage, congestion, and atelectasis. Kidneys and spleen also were congested.

Applicant's summary and conclusion

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

The acute oral LD50 values of 2,2'-bipyridine were 100 mg/kg bw in male and 107 mg/kg bw in female rats.

Executive summary:

Acute oral toxicity of 2,2’-bipyridine was determined in a gavage assay on rats. Groups of 10 male or female rats were treated by gavage with the test item as 2% solution in 20% ethanol. Dosing was 75 mg/kg bw for male and female groups, 120 mg/kg bw female, 150 mg/kg male. Observation period was 14 days; subsequently, animals were killed and a necropsy was performed.

The acute oral LD50 values of 2,2'-bipyridine were 100 mg/kg bw in male and 107 mg/kg bw in female rats. The steepness of the dose-response curve is quite high: while at 75 mg/kg no effects were observed, 80% of the females died at 120 mg/kg bw and all males died at 150 mg/kg bw. Clinical signs included immediate subdued behaviour, loss of muscle coordination, red urine, and tremors. Convulsions were observed immediately before death which occurred 1 or 2 d after dosing.