title: Expression and localization of the cysteinyl leukotriene 1 receptor in human nasal mucosa.
abstract: BACKGROUND
  The cysteinyl leukotrienes (CysLT) are lipid mediators that have been implicated in the pathogenesis of allergic diseases. Pharmacological studies using CysLTs indicate that two classes of receptors, named CysLT1 and CysLT2 receptor, exist. The former is sensitive to the CysLT1 antagonist currently used to treat asthma and allergic rhinitis. Recently, the cDNA for human CysLT1 and CysLT2 receptor have been cloned, making it now possible to study the gene expression of CysLTs receptors.
  
  
  OBJECTIVE
  We have used reverse transcription and polymerase chain reaction (RT-PCR) to study the gene expression of CysLT1 and CysLT2 receptor and in situ hybridization to determine the distribution of CysLT1 receptor mRNA in human nasal mucosa. In addition, the distribution of the CysLT1 receptor protein was studied by immunohistochemistry.
  
  
  METHODS
  Human turbinates were obtained after turbinectomy from six patients with nasal obstruction refractory to medical therapy. Total RNA was isolated from human nasal mucosa and both CysLT1 and CysLT2 receptor mRNA was detected in these tissues by using RT-PCR. For in situ hybridization study of human nasal mucosa, we used biotin-labelled oligonucleotides probes encoding human CysLT1 receptor cDNA. To identify the cells expressing the CysLT1 receptor protein, double immunostaining was performed by using anti-CysLT1 receptor antibody and monoclonal antileucocyte antibodies.
  
  
  RESULTS
  RT-PCR analysis of total nasal RNA demonstrated the expression of both CysLT1 receptor and CysLT2 receptor mRNA. In situ hybridization indicated high levels of CysLT1 receptor hybridization in blood vessels and the interstitial cells, but a sparse signal in airway epithelium and submucosal glands. The immunohistochemical studies revealed that anti-CysLT1 receptor antibody labelled eosinophils, mast cells, macrophages, neutrophils and vascular endothelial cells in the nasal mucosa.
  
  
  CONCLUSIONS
  The results may have an important clinical implication and also promote further investigation of the regulation of CysLT1 receptor in health and disease.
authors.affiliation: Department of Otolaryngology, Sapporo Medical University, School of Medicine, Sapporo, Japan. puchibe@spa.att.ne.jp
authors.forename: H
authors.initials: H
authors.lastname: Shirasaki
authors.forename: E
authors.initials: E
authors.lastname: Kanaizumi
authors.forename: K
authors.initials: K
authors.lastname: Watanabe
authors.forename: T
authors.initials: T
authors.lastname: Matsui
authors.forename: J
authors.initials: J
authors.lastname: Sato
authors.forename: S
authors.initials: S
authors.lastname: Narita
authors.forename: M
authors.initials: M
authors.lastname: Rautiainen
authors.forename: T
authors.initials: T
authors.lastname: Himi
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D017998:Leukotriene D4 / Q000494:pharmacology; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D009297:Nasal Mucosa / Q000737:chemistry / Q000378:metabolism*; D018077:Receptors, Leukotriene / Q000032:analysis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D008565:Membrane Proteins; D018077:Receptors, Leukotriene; D017998:Leukotriene D4; C412375:cysteinyl leukotriene receptor 2; C083169:leukotriene D4 receptor