An improvement of LLNA:DA to assess the skin sensitization potential of chemicals.
We developed a modified local lymph node assay based on ATP (LLNA:DA), termed the Two-Stage LLNA:DA, to further reduce the animal numbers in the identification of sensitizers. In the Two-Stage LLNA:DA procedure, 13 chemicals ranging from non-sensitizers to extreme sensitizers were selected. The first stage used reduced LLNA:DA (rLLNA:DA) to screen out sensitive chemicals. The second stage used LLNA:DA based on OECD 442 (A) to classify those potential sensitizers screened out in the first stage. In the first stage, the SIs of the methyl methacrylate, salicylic acid, methyl salicylate, ethyl salicylate, isopropanol and propanediol were below 1.8 and need not to be tested in the second step. Others continued to be tested by LLNA:DA. In the second stage, sodium lauryl sulphate and xylene were classified as weak sensitizers. a-hexyl cinnamic aldehyde and eugenol were moderate sensitizers. Benzalkonium chloride and glyoxal were strong sensitizers, and phthalic anhydride was an extreme sensitizer. The 9/9, 11/12, 10/11, and 8/13 (positive or negative only) categories of the Two-Stage LLNA:DA were consistent with those from the other methods (LLNA, LLNA:DA, GPMT/BT and HMT/HPTA), suggesting that Two-Stage LLNA:DA have a high coincidence rate with reported data. In conclusion, The Two-Stage LLNA:DA is in line with the "3R" rules, and can be a modification of LLNA:DA but needs more study.
Department of Toxicology, National Institute of Environmental Health, Chinese Center for Desease Control and Prevention, China.
Hongwei
H
Zhang
Ying
Y
Shi
Chao
C
Wang
Kangfeng
K
Zhao
Shaoping
S
Zhang
Lan
L
Wei
Li
L
Dong
Wen
W
Gu
Yongjun
Y
Xu
Hongjie
H
Ruan
Hong
H
Zhi
Xiaoyan
X
Yang
D000255:Adenosine Triphosphate / Q000378:metabolism; D000485:Allergens / Q000633:toxicity*; D000818:Animals; D017449:Dermatitis, Allergic Contact / Q000209:etiology*; D005260:Female; D023441:Local Lymph Node Assay; D008198:Lymph Nodes / Q000166:cytology; D008807:Mice, Inbred BALB C
D000485:Allergens; D000255:Adenosine Triphosphate