Lipopolysaccharide Inhibits the Channel Activity of the P2X7 Receptor
LPS inhibits ATP-induced intracellular calcium increases in P2X7R-HEK293 cells. (a) Representative tracings of a single cell responding to different ATP concentrations and to 60 μM of the P2X7R-agonist BzATP. (b) Representative recordings showing the lack of effects of LPS in the absence of FBS. (c) Representative recordings showing the time dependent inhibition of ATP-induced calcium transients induced by 1 μg/mL LPS, in the presence of 1% FBS. (d) Summary of the inhibition induced by 7 min of LPS preapplication (, ). (e) Recordings of calcium increases induced by 60 μM BzATP and inhibition by the pre-application of LPS. Similar results were observed in 3 different cells. (f) Recordings in the absence of extracellular calcium, in the absence (black tracing), and in the presence (gray tracing) of LPS (preapplied for 7 min).