2K1706 Increased expression of histamine H1 receptor mRNA in nasal mucosa of rats sensitized by toluene diisocyanate

• Published in: Journal of Pharmacological Sciences 2003, Vol.91 (suppl.1), p.99-99
• Main Authors: Yoshiaki Kitamura, Ayako Miyoshi, Yuki Murata, Noriaki Takeda, Hiroyuki Fukui
• Format: Article
• Language: Japanese
• ISSN: 1347-8613

Previously, we developed a nasal hypersensitivity animal model of guinea pigs sensitized by toluene diisocyanate (TDI) and showed that on exposure to TDI, neurogenic inflammation in the nasal mucosa induced the release of histamine, resulting in the development of symptoms of nasal allergy. In the present study, we used TDI-sensitized rats as a model of nasal hypersensitivity and examined changes of the expression of histamine H1 receptor (H1R) mRNA in nasal mucosa after exposure to TDI by means of real-time quantitative RT-PCR. Intranasal application of TDI induced nasal allergy-like behavior such assneezing and watery rhinorrhea in rats sensitized by TDI. Intranasal application of TDI also increased the expression of H1R mRNA in nasal mucosa of rats sensitized by TDI. In rats pretreated with H1R antagonist, chlorpheniramine, TDI-induced nasal allergy-like behavior was suppressed. Chlorpheniramine also inhibited the increase of H1R mRNA expression in the nasal mucosa induced by TDI. These findings indicate that on exposure to TDI, released histamine via H1R induced not only nasal allergy-like behavior , but also the up-regulation of H1R. Since the up-regulation of H1R in the nasal mucosa increases nasal hypersensitivity, it is suggested that pretreatment of H1R antagonist inhibits both nasal allergy symptom and nasal hypersensitivity.