2-Aminoethoxydiphenyl borate reduces degranulation and release of cytokines in a rat mast cell line.

BACKGROUND AND OBJECTIVE 2-aminoethoxydiphenyl borate (2-APB) has been reported to be a useful pharmacological tool in the study of calcium signaling. It is used either as a membrane-permeable inhibitor for inositol 1,4,5-trisphosphate (IP3) receptors or a store-operated calcium (Ca2+) entry (SOCE) inhibitor. The present study aimed to evaluate the effects of 2-APB on degranulation and cytokine production after antigen activation in a rat mast cell line, RBL-2H3 cells. MATERIALS AND METHODS Degranulation levels were analyzed by beta-hexosaminidase assay. Intracellular calcium concentrations were measured by Fluo-3 assay. The mRNA expression of interleukin-4 (IL-4) and tumor necrosis factor (TNF)-alfa were analyzed by Real-time PCR. RESULTS The intracellular Ca2+ levels were greatly suppressed in the absence or presence of 2 mmol/L Ca2+ in the extracellular medium when RBL-2H3 cells were pretreated with 100 micromol/L 2-APB for 15 min. The beta-hexosaminidase activity as well as the mRNA expression of IL-4 and TNF-alfa levels were significantly decreased after application of 2-APB. CONCLUSION This study indicates that the application of 2-APB may be a useful method to inhibit mast cell activation.