Registration Dossier

Toxicological information

Skin sensitisation

Currently viewing:

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: well performed study in compliance with elementary guideline requirements

Data source

Reference
Reference Type:
publication
Title:
COMPARISON OF THE LOCAL LYMPH NODE ASSAY WITH THE GUINEA-PIG MAXIMIZATION TEST FOR THE DETECTION OF A RANGE OF CONTACT ALLERGENS
Author:
BASKETTER D. A. and SCHOLES E. W.
Year:
1992
Bibliographic source:
Food and chemical toxicology, Vol 30, 65-69

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
other: Basketter et al., 1991 and OECD 429
Deviations:
yes
Remarks:
method prior to OECD guideline
Principles of method if other than guideline:
CBA/Ca mice were used at the age of 8-12 wk. Animals of both sexes were used, but single experiments were limited to one sex. The test substance was assayed at three consecutive concentrations from the following range: 100, 50, 25, 10, 5, 2.5, 1.0, 0.5, 0.25, 0.1, 0.05 and 0.01%. Groups of four mice were treated by a daily topical application of 25 µl of each concentration on the dorsal surface of each ear for 3 consecutive days. Control mice were treated with the vehicle alone. 4-5 days after the first topical application, all mice were injected intravenously through the tail vein with 250 µl phosphate buffered saline (PBS) containing [3H]methyl thymidine (3HTdR; 20 µCi). After 5 h the mice were killed by carbon dioxide asphyxiation, and the draining auricular lymph nodes were excised and pooled for each experimental group. A single-cell suspension of lymph node cells (LNC) was prepared by gentle mechanical disaggregation through a stainless-steel gauze (200-mesh size), using the plunger of a syringe. Pooled LNC were pelleted at 190 g for 10 min, washed twice with 10 ml PBS and resuspended in 3 ml trichloroacetic acid (TCA; 5%) for the precipitation of macromolecules. After an overnight incubation with TCA at 4°C, the precipitate was recovered by centrifugation, resuspended in 1 ml TCA and transferred to 10 ml scintillation fluid. 3HTdR incorporation was measured by β-scintillation counting. The proliferative response of LNC was expressed as radioactive disintegrations per min per lymph node (dpm/node), and as the ratio of 3HTdR incorporation into LNC of test nodes relative to that recorded for control nodes (test/control ratio). A chemical was regarded as a sensitizer in the LLNA if at least one concentration of the chemical resulted in a three-fold or greater increase in 3HTdR incorporation compared with control values. Also, the data had to be compatible with a biological dose response although an allowance was made, especially at high doses, for either local toxicity or immunological suppression.
GLP compliance:
not specified
Type of study:
mouse local lymph node assay (LLNA)

Test material

Constituent 1
Chemical structure
Reference substance name:
p-phenylenediamine
EC Number:
203-404-7
EC Name:
p-phenylenediamine
Cas Number:
106-50-3
Molecular formula:
C6H8N2
IUPAC Name:
benzene-1,4-diamine
Details on test material:
Several substances were tested in this study, the vast majority of these compounds were more than 98% pure.

In vivo test system

Test animals

Species:
mouse
Strain:
other: CBA/Ca
Sex:
male/female
Details on test animals and environmental conditions:
CBA/Ca mice were used at the age of 8-12 wk. Animals of both sexes were used, but single experiments were limited to one sex.

Study design: in vivo (LLNA)

Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
2.5, 5, 10%
No. of animals per dose:
4
Details on study design:
Exposure period: 4 d
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:
T/C ratio (ratio of test to control lymphocyte proliferation) of Cinnamic aldehyde
5%: 12.5
10%: 18.4
25%: 15.4

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: T/C ratio (ratio of test to control lymphocyte proliferation) of p-Phenylene diamine 2.5%: 12.8 5%: 16.5 10%: 23.3
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: DPM data are not presented in the publication.

Applicant's summary and conclusion

Interpretation of results:
sensitising
Remarks:
Migrated information
Conclusions:
p-Phenylene diamine was considered to be a skin sensitiser under the conditions of this test.
Executive summary:

A sample of p-Phenylene diamine was assessed for its skin sensitisation potential using the mouse Local Lymph Node Assay. The test sample was applied as 2.5, 5.0, 10.0 % preparations in acetone-olive oil (4:1, v/v).

p-Phenylene diamine was shown to have the capacity to cause skin sensitisation when apllied as 2.5, 5.0, 10.0 % preparations.

In a positive control study, hexylcinnamaldehyd was shown to have the capacity to cause skin sensitisation, confirming the validity of the protocol used in this study.

In conclusion, p-Phenylene diamine was considered to be a skin sensitiser under the conditions of this test.