(A) P2X receptor expression in Jurkat cells was evaluated by RT-PCR analysis. Human brain cDNA was used as a template for positive controls, and cDNA synthesis in the absence of RT was used as a negative control. (B) Using real-time RT-PCR analysis, changes in P2X1, P2X4, P2X5, and P2X7 receptor expression were determined after stimulation of Jurkat cells with 40 mM HS for 0, 1, 4, and 20 h (*P<0.05 compared with unstimulated controls; two-tailed unpaired Student's t tests; n=3).