The gene expression of histamine receptor in endothelial cells and eosinophils

Abstract

Histamine is a potent mediator of nasal inflammatory and allergic reactions. It is vasoactive, mediating vasodilation and plasma extravasation, and it promotes eosinophil migration.
In this study, expression of the histamine receptor gene in eosinophils and endothelial cells was investigated using the reverse transcription-polymerase chain reaction. We detected histamine H1 receptor (H1R) mRNA in endothelial cells isolated from the nasal mucosa of patients with nasal allergy and patients with nonallergic rhinitis. There was no diffference between the amount of H1R gene expression in the two groups. We were unable to detect H2R mRNA in endothelial cells from either patients with nasal allergy or nonallergic rhinitis. Neither H1R nor H2R was defected in eosinophils isolated from peripheral blood. The effect of cytokines on H1R and H2R gene expression was investigated. Interleukin (IL)-2, IL-3, IL-4, IL-5, tumor necrosis factor-α and granulocyte colony stimulating factor did not alter H1R or H2R gene expression. These findings have raised the possibility that histamine stimulates endothelial cells via the H1R but not the H2R. The class of histamine receptor in eosinophils has not been identified.