%0 Journal Article
%T Localization and Upregulation of the Nasal Histamine H1 Receptor in Perennial Allergic Rhinitis
%A Hideaki Shirasaki
%A Etsuko Kanaizumi
%A Nobuhiko Seki
%A Tetsuo Himi
%J Mediators of Inflammation
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/951316
%X In the present study, we have investigated the expression of histamine H1 receptor in human turbinates by RT-PCR, western blotting, and immunohistochemistry. Human turbinates were obtained by turbinectomy from 12 patients with nasal obstruction refractory to medical therapy. RT-PCR analysis of total RNA extracted from human nasal turbinate, primary cultured human nasal epithelial cells, and nasal vascular endothelial cells demonstrated the expression of histamine H1 receptor mRNA. About 56£¿kDa band was detected in human turbinates by western blot analysis using anti-H1 receptor antibody. The expression level of H1 receptor protein was marked in patients with nasal allergy than in patients with nonallergic rhinitis. The immunohistochemical study revealed that epithelial cells and vascular endothelial cells showed intense immunoreactivity for histamine H1 receptor. In addition, the blood vessels in superficial area expressed higher level of H1 receptor immunoreactivity than that in deeper area in the nasal mucosa. These results may have an important clinical implication for understanding the role of histamine H1 receptor on upper airway diseases such as allergic rhinitis and nonallergic rhinitis. 1. Introduction The allergic response is a complex process involving the interaction of many mediators. Histamine is the most important mediator in the pathogenesis of nasal allergy [1]. Administration of exogenous histamine into human nasal airway causes nasal obstruction, rhinorrhea, and sneezing [2]. These effects appear to be mediated by histamine H1 receptor because H1 receptor antagonists abolish histamine-induced nasal symptoms [3]. To understand the role of histamine on nasal allergy, the information about the localization of histamine H1 receptor is very important. However, limited numbers of studies have been reported. The previous autoradiografic study using 3H-pyrilamine has demonstrated H1 receptor existed exclusively on the endothelium of vessels [4]. More recently, Sanico et al. found that not only vascular endothelial cells but also epithelial cells and nerves expressed histamine H1 receptor on human inferior turbinates by immunohistochemical studies [5]. Mucosal hyperreactivity to histamine can be observed in patients with perennial allergic rhinitis, suggesting upregulation of histamine H1 receptor may exist [5]. However, little is known about upregulation of H1 receptor protein in upper airway. In the present study, western blotting, immunohistochemistry, and RT-PCR analysis for histamine H1 receptor were performed to confirm both mRNA and
%U http://www.hindawi.com/journals/mi/2012/951316/