4-vinylpyridine

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Performed non-GLP by a reputable laboratory. Due to the corrosive nature of the substance, consideration of repeating this study is inappropriate.

Data source

Reference

Reference Type:

publication

Title:

Anamnestic responses to contact allergens: application in the murine local lymph node assay

Author:

Kimber I and C Weisenberger

Year:

1991

Bibliographic source:

J. Applied Toxicology, 11(2), 129-33

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

yes

Remarks:

modified to include a dermal exposure 5 days prior to main treatment

GLP compliance:

not specified

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

4-vinylpyridine

EC Number:

202-852-0

EC Name:

4-vinylpyridine

Cas Number:

100-43-6

Molecular formula:

C7H7N

IUPAC Name:

4-ethenylpyridine

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

not specified

Details on test animals and environmental conditions:

The strain was CBA/ca. Three animals were used per substance.

Study design: in vivo (non-LLNA)

Positive control substance(s):

not specified

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

50 microliters undiluted, for 48 hours, 5 days prior to the main exposure. The main exposure was 25 microliters of test material. Treatment was applied for 3 consecutive days.

No. of animals per dose:

3

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: soluble
- Irritation: no data
- Lymph node proliferation response:

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Modified LLNA
- Criteria used to consider a positive response: Increased draining lymph node cell proliferation

TREATMENT PREPARATION AND ADMINISTRATION:
Fifty microliters of the test chemical was applied on one shaved flank under an occluded patch, covered with latex rubber and secured with a poroplast bandange and 1 cm tape. Patches were removed after 48 hours. Five days following primary exposure, all mice received 25 microliters of the test chemical or vehicle on the dorsum of both ears. This treatment was performed daily for 3 consecutive days and mice were killed 1 day after the final exposure. Draining auricular lymph nodes were excised, pooled for each experimental group and weighed. A single-cell suspension of lymph node cells (LNC) was prepared under aseptic conditions by mechanical disaggregation, washed and suspended in RPMI-1640 culture medium supplemented with 25 mM HEPES, ampiciliin, streptomycin and 10% heat-inactivated FCS. Viable cell counts were obtained and the lymphocyte suspensions were seeded in 96-well microtiter plates and cultered for 24 h at 37 degrees C in humidified air with 2 microCi per mmole tritieated methyl thymidine. Duplicate cultures were supplemented with a source of interleukin 2 (IL2).
Interleukin 2-rich supernatants were derived from TPA-stimulated cultures of the EL-4 murine thymoma line.
LNC suspensions were centrifuged, air dried and fixed with methanol for 5 min. Slides were stained with pyronin for 75 minutes, and counterstained with methyl green in 0.1 M acetate buffer, pH 6.4) stained slides were washed with water and the frequency of pyroninophilic lymphocytes was measured by inspection of at least 300 cells by oil-immersion microscopy.

In situ analysis: Mice were injected IV (tail vein) with tritiated-methyl thymidine 1 day following the final exposure to the ears of mice. Mice received 250 microliters of PBS containing 20 microCi of thymidine. Five hours later, mice were killed and draining auicular nodes were excised and pooled for each experimental group. A single cell suspension of LNC were prepared by gentle mechanical disaggregation through 200-mesh stainless-steel gauze. Pooled LNC were washed and precipitated with 5% TCA at 4 degrees C. Twelve hours later, pellets were resuspended in 1 ml TCA and transferred to 10 ml of scintillation fluide (Optiphase MP, LKB). Incorporation of tritiated TdR was measured by scintillation counting and expressed as mean cpm per node for each experimental group.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

No information provided

Results and discussion

Positive control results:

Lymph node cell proliferation was increased after exposure to 5% cinnamic aldehyde.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: >3

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: At 5% 4VP, the enhanced exposure conditions (pre-exposure on the flank of the animal 5 days prior to the main treatment) resulted in approximately 8 cpm/node E-02 compared to vehicle (approximately 4.5 cpm/node E-02).

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

In a study in which the modified LLNA was being developed, 4-vinylpyridine elicited an increased lymphocyte proliferation reaction which was greater when pre-exposure occurred. 4-Vinylpyridine is considered sensitizing under these conditions.