Modulation of endothelin-induced intracellular Ca2+ mobilization by interleukin-1β and lipopolysaccharide in C6 rat glioma cells

Abstract We have investigated the effects of interleukin (IL)-1β and lipopolysaccharide (LPS) on endothelin (ET)-induced intracellular Ca 2+ rise in C6 rat glioma cells in order to study the mechanisms of their effects on Ca 2+ signaling systems. Pretreatment with IL-1β (10 3 U/mL) and LPS (1 μg/mL) for 24 h significantly inhibited 100 nM ET-1-induced increase in intracellular Ca 2+ either in the presence or absence of external Ca 2+ . Their inhibitory effects were in dose-dependent (IL-1β; 50–1000 U/mL, LPS; 10–1000 ng/mL) and time-dependent (12–24 h) manners. A tyrosine kinase antagonist genistein (50 μM) but not a protein kinase C inhibitor H7 (30 μM) prevented the inhibition of the ET response by IL-1β and LPS. These results suggest that activation of tyrosine kinase may be essential for the inhibition of the ET receptor-mediated Ca 2+ signaling systems by IL-1β and LPS.