We describe here methods for neonatal capsaicin treatment to induce atopic dermatitis in rats and exposure of vaporized formaldehyde to investigate the effects of formaldehyde inhalation on atopic dermatitis.
A subscription to JoVE is required to view this content. Sign in or start your free trial.
Method Article
Effects of Exposure of Formaldehyde to a Rat Model of Atopic Dermatitis Induced by Neonatal Capsaicin Treatment
In This Article
Summary
Abstract
Atopic dermatitis is chronically relapsing pruritic eczema and prevails around the world especially in developed countries. Complex interactions between genetic and environmental factors are known to play an important role in the pathophysiology of atopic dermatitis. However, we still lack a detailed picture of the pathogenesis of this disease. Thus, it is of importance to develop appropriate animal models for elucidating the progression of atopic dermatitis. Moreover, investigating the effect of environmental factors such as air pollutants on atopic dermatitis expands understanding of the disease. Here, we describe a method for inducing atopic dermatitis in rats with neonatal capsaicin treatment and a protocol for exposure of a constant concentration of formaldehyde to rats to reveal effects on the development of atopic dermatitis in infantile and adolescent periods. These protocols have been successfully applied to several experiments and can be used for other substances.
Introduction
To interrogate the effects of formaldehyde (FA) inhalation on atopic dermatitis (AD) progression, we established a protocol for AD induction and developed a conventional circulation chamber for chronic exposure of FA.
AD is a chronic inflammatory skin disease attributed to the complex interactions between genetic predisposition and environmental triggers1,2. A proper animal model is required to study AD in the preclinical state. This is most important when elucidating the pathogenesis of AD under the influence of environmental factors. Moreover, to better investigate the effects of ....
Access restricted. Please log in or start a trial to view this content.
Protocol
All methods described here have been approved by the International Animal Care and Use Committee (IACUC) of Korea University College of Medicine. 6 weeks after birth, experimenters can induce enthansasia and collect various samples such as the skin and serum of rats.
1. Induction of AD by Neonatal Capsaicin Treatment
- To prepare 5 mg/mL capsaicin solution, add 50 mg of capsaicin to 1 mL of Tween 80 and 1 mL of 100% ethanol in a 15 mL conical tube.
- Add 8 mL of normal saline to the conical tube. Shake the tube vigorously until no separated layers are visible
- Inject the capsaicin solution (10 µL/....
Access restricted. Please log in or start a trial to view this content.
Results
The AD-like skin inflammation of the capsaicin-treated AD rat model at 7 weeks of age is presented in Figure 1A. Robust scratching behaviors of the capsaicin-treated AD rat model is shown in Video 1. Neonatal capsaicin treatment elicited dermatitis and aggravated scratching behaviors in rats 3 weeks of age, and AD-like symptoms persisted for several weeks (Figure 1B, C). Though the degree was les.......
Access restricted. Please log in or start a trial to view this content.
Discussion
The protocol described here for the induction of AD-like symptoms in rats can be adapted for studying AD pathophysiology and used as a screening tool for drug test. The instrument for the exposure of gaseous FA to capsaicin-treated rats can be applied to evaluate the effects of exposure to various gases on diverse animal models.
The neonatal capsaicin-treated AD model relies on a more simple procedure than other atopic models such as the DNCB treatment model9 and epicut.......
Access restricted. Please log in or start a trial to view this content.
Disclosures
The authors have nothing to disclose.
Acknowledgements
This research was supported by the Public Welfare & Safety research program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2014M3C8A5030612), and supported by The Chung Yang, Cha Young Sun, M.D. and Jang Hi Joo Yeu Sa Memorial Fund.
....Access restricted. Please log in or start a trial to view this content.
Materials
| Name | Company | Catalog Number | Comments |
|---|---|---|---|
| Medical Oxygen Regulator | Yuyao Jiahua Medical | manufacturer will not affect results | |
| Tube | manufacturer will not affect results | ||
| Acrylic Chamber | Taejin Acryl | manufacturer will not affect results | |
| Plastic Chamber | Taejin Acryl | manufacturer will not affect results | |
| Paraformaldehyde, powder | Sigma | 158127 | manufacturer will not affect results |
| Wrap filme | Uniwrap | manufacturer will not affect results | |
| Capsaicin | Sigma | M2028 | manufacturer will not affect results |
| Tween 80 | Sigma | P4780 | manufacturer will not affect results |
| Digital Video Camera | Sony | HDR-CX380y | manufacturer will not affect results |
| Isoflurane | JW pharmaceutical | manufacturer will not affect results |
References
- Geha, R. S. Allergy and hypersensitivity. Nature versus nurture in allergy and hypersensitivity. Curr Opin Immunol. 15 (6), 603-608 (2003).
- Novak, N., Bieber, T., Leung, D. Y. Immune mechanisms leading to atopic dermatitis. The J Allergy Clin Immunol.
Access restricted. Please log in or start a trial to view this content.
Reprints and Permissions
