Dermal mast cells play a central role in the incidence of scratching behavior in mice induced by multiple application of the hapten, 2,4,6-trinitrochlorobenzene.
Repeated application of 1% 2,4,6-trinitrochlorobenzene (TNCB) in acetone solution causes chronic skin inflammation in BALB/c mice. Associated scratching behavior gradually appeared, and chronic scratching behavior was established over 40 days after the initial application of TNCB. In order to explore the possible involvement of T cells and mast cells in the appearance of pruritus, we examined the response of athymic nude mice and genetically mast-cell-deficient mice. We could not detect either severe skin inflammation or immunoglobulin (Ig)E production in T-cell-deficient BALB/c nu/nu mice even after 80 days of TNCB treatment, whereas typical severe skin inflammation and IgE production were observed in mast-cell-deficient WBB6F1-W/Wv and WBB6F1-Sl/Sld mice. Furthermore, we observed persistent scratching behavior in WBB6F1-W/Wv mice, but not in BALB/c nu/nu and WBB6F1-Sl/Sld mice. Histological examination of TNCB-treated animals revealed the development of dermal mast cells in W/Wv mice but not in Sl/Sld mice. Degranulation of dermal mast cells was observed in the WBB6F1-W/Wv genotype, but most mast cells remained intact in TNCB-treated BALB/c nu/nu mice. These results suggest that mast cells play a pivotal role in the incidence of scratching behavior in this chronic pruritus model.
Yamashita
Hirotaka
H
Graduate School of Pharmaceutical Sciences, Nagoya City University, Tanabe-dori, Mizuho-ku, Nagoya, Japan.
Michibata
Yoshiko
Y
Mizukami
Hajime
H
Ogihara
Yukio
Y
Morita
Akimichi
A
Nose
Mitsuhiko
M
D000096:Acetone / Q000737:chemistry; D000818:Animals; D005260:Female; D005838:Genotype; D006241:Haptens; D007073:Immunoglobulin E / Q000737:chemistry; D007249:Inflammation; D008297:Male; D008407:Mast Cells / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D010853:Picryl Chloride / Q000494:pharmacology; D011537:Pruritus / Q000139:chemically induced* / Q000473:pathology; D012867:Skin / Q000166:cytology*; D013601:T-Lymphocytes / Q000378:metabolism; D013997:Time Factors
D006241:Haptens; D000096:Acetone; D007073:Immunoglobulin E; D010853:Picryl Chloride