Fig. 4.

ATP-induced P2X7R-mediated sustained Ca²⁺ influx, and IL-1β maturation and release were not observed in the swine liver-derived macrophages despite the fact that they expressed P2X7R. P2X7R agonists (ATP and BzATP) failed to trigger sustained increases in the [Ca²⁺]_i of the swine liver macrophages, whereas LPC triggered a sustained [Ca²⁺]_i increase (A). ATP-induced mIL-1β release was not detected in the LPS-primed swine liver macrophages, whereas nigericin triggered mIL-1β release (B). P2X7R mRNA and protein expression was detected in the swine liver macrophages by RT-PCR (C) and by immunoblotting (D), respectively. Equivalent protein loading in each lane was confirmed by immunoblotting with anti-actin antibody (D). All data shown are representative of two or three independent experiments.