抄録
We examined the effect of antiallergic drugs, azelastine and epinastine, on the FcεRI expression of rat basophilic leukemia (RBL-2H3) cells. The cells were cultured for 24 hours with or without rat IgE stimulation in the presence of azelastine or epinastine at the concentration of 10−5 M. The FcεRIα mRNA expression was determined by Northern blot analysis. The FcεRI protein of the cell was examined by immunoprecipitation with anti-FcεRIα, followed by Western blot analysis with anti-γ chain of FcR. The FcεRI protein expressed on the cytomembrane following to IgE stimulation was examined by immunoprecipitation with anti-IgE light chain, followed by Western blot analysis with anti-γ chain of FcR. The level of phosphorylated and nonphosphorylated γ chain of FcεRI precipitated with anti-IgE light chain following to IgE stimulation was suppressed by both azelastine and epinastine. Neither the effect of azelastine and epinastine on the FcεRIα mRNA level nor their effects on the γ chain level of FcεRI precipitated with anti-FcεRIα was observed. The possible mechanisms whereby azelastine and epinastine exert their effects on the γ chain level of FcεRI interacted with IgE are as follows: 1) inhibition of IgE-FcεRI interaction; 2) inhibition of FcεRI expression on the cytomembrane; 3) inhibition of FcεRI signaling. [Jpn J Physiol 55 Suppl:S235 (2005)]
