Fig. 4.

P2X1 ion channels contribute to the S. sanguinis -induced FcγRIIa receptor Ca ²⁺ responses ( A ) Representative Ca ²⁺ responses measured when S. sanguinis was added with and without 600 nM α,β-meATP pretreatment, together with the vehicle (PBS) control (i). α,β-meATP pretreatment diminished the transient Ca ²⁺ peak that occurred after bacterial stimulation [shown in dashed rectangular box in (i), which is expanded in (ii)]. ( B ) Average peak [Ca ²⁺ ] _i responses obtained within 25 minutes (i) and 2.5 minutes (ii) after bacterial stimulation, with and without α,β-meATP pretreatment.