Figure 7. Inhibitory effects of suramin, a non-selective P2 purinoceptor antagonist, and PPADS, a selective P2X purinoceptor antagonist, on EJP induced by oral NS.

A and C, raw recordings of resting membrane potentials. Ba–c and Da–c, the EJP induced by 4 pulses or oral NS at expanded time scale before, during and after application of suramin and PPADS, respectively. Bd and Dd, superimposed EJPs. Resting membrane potential was not affected by suramin, but was significantly depolarized by PPADS. Suramin reached maximal inhibitory effects on the EJP in 15 min, while maximal PPADS effect occurred within 10 min. Effects of suramin and PPADS reversed within 15 min after washing out.