A potent and selective competitive antagonist of the P2X7 receptor (IC50s = 9.9 and 10.9 nM in 132N1 cells transfected with the rat or mouse receptor, respectively), inhibits IL-1β release in LPS and IFN-γ-stimulated THP-1 cells (IC50 = 8.5 nM); selective over other P2X and P2Y receptors at concentrations up to 100 μM; prevents footshock-induced increases in IL-1β mRNA in the rat hypothalamus ,