PXR agonists trigger rapid and significant ATP release from mouse and human macrophages. (A) PCN, a mouse PXR agonist, triggers rapid and significant ATP release from LPS-pulsed peritoneal macrophages isolated from wild-type mice, an effect that is absent in cells isolated from PXR−/− mice. N = 3; *P < 0.05 for wild-type (WT) PCN-treated macrophages compared with naive and PXR−/− cells generated by analysis of variance and Tukey’s post hoc test. (B) Human PXR agonists, rifaximin (Rifx) and SR12813 (SR), trigger rapid and significant ATP release from PMA-differentiated THP-1 cells. N = 3; *P < 0.05 for indicated comparison generated by analysis of variance and Tukey’s post hoc test.