[Effect of inhibitors of mitochondrial oxidative metabolism on Ca-responses induced by purinergic agonists and thapsigargin in rat peritoneal macrophages].

Effects of two metabolic inhibitors, oligomycin and carbonyl cyanide m-fluorophenylhydrazone (FCCP), on Ca2+ signals induced by purinergic agonists and thapsigargin in Fura-2-loaded rat peritoneal macrophages was investigated. 1 microgram/ml oligomycin or 1 microM FCCP were shown to inhibit 200 microM ATP or 200 microM UTP-evoked Ca2+ entry in macrophages. Independently of their chemical structure and site of inhibition, both metabolic poisons also inhibit the store-dependent or "capacitative" Ca2+ influx stimulated by emptying the intracellular Ca2+ stores with endoplasmic Ca(2+)-ATPase inhibitor thapsigargin (0.5 microM). These data are compatible with the important role the energy level of the cell plays in the control of Ca2+ entry in rat peritoneal macrophages.