FIGURE 8.
Effect of AST on ATP-activated currents in HEK293 cells expressing P2X4. (A) Representative traces showing that AST (50 μM) inhibited the ATP (100 μM)-induced current in HEK293 cells transfected with P2X4 plasmid. Control cells not transfected with P2X4 do not respond to ATP at the concentrations. (B) Histogram of current density in the presence of indicated drugs. AST (50 μM) and the P2X4-selective antagonist 5-BDBD (10 μM) inhibited the ATP-activated current in HEK293 cells. DMSO has no effect on ATP-activated current. (C) Concentration–response curve for AST obtained with 100 μM ATP. The IC50 value 33.73 ± 2.25 μM was derived from the equation of the sigmoidal function giving the best fit to the data. Each data point represents mean ± SEM of six cells. ***p < 0.001 compared with ATP current produced by the cells transfected with P2X4 receptor in the absence of drugs.