The Open Allergy Journal

2014, 7 : 10-16
Published online 2014 November 19. DOI: 10.2174/1874838401407010010
Publisher ID: TOALLJ-7-10

Distinct Reactivity of Transient Receptor Potential Vanilloid Subtype 1 in a Murine Model of Atopic Dermatitis with Serious Scratching

Yan Xia , Akane Tanaka , Kumiko Oida , Akira Matsuda , Hyosun Jang , Yosuke Amagai , Saori Ishizaka and Hiroshi Matsuda
Laboratories of Comparative Animal Medicine and Veterinary Molecular Pathology and Therapeutics, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.

ABSTRACT

Background:

Abnormality in skin sensitivity may be responsible for unbearable itch in patients with atopic dermatitis (AD).

Objectives:

We evaluated reactivity of NC/Tnd mice, a model for human AD, against various experimental stimulations.

Methods:

Several behavioral tests were performed after external stimuli were applied to NC/Tnd mice. Transient receptor potential vanilloid subtype 1 (TRPV1) reactivity of neuronal cells collected from the dorsal root ganglions (DRG) was analyzed with a Ca++ influx test. Finally, we evaluated suppressive effect of capsaicin on atopic itch of NC/Tnd mice.

Results:

Pain responses to heat, acidic stimulation, and capsaicin injection, which are transduced through TRPV1, were decreased in NC/Tnd mice, when compared to two standard strains BALB/c and C57BL/6 mice. The reactivity of the primary neurons isolated from DRG to capsaicin was markedly reduced in NC/Tnd mice. Topical application of histamine evoked scratching in NC/Tnd mice as well as other two strains; however, the scratching intensities induced by nonhistamine pruritogens were significantly lower in NC/Tnd mice comparing to the two strains. In conventional NC/Tnd mice with AD, topical application of capsaicin reduced the scratching behavior.

Conclusion:

TRPV1 is associated with both pain and itch sensation; however, abnormalities in TRPV1 reactivity may involve in severe itch in NC/Tnd mice.

Keywords:

Atopic dermatitis, itch, NC/Tnd mice, TRPV1.