Using Fura-2AM microfluorimetry, the effect of neuroleptic trifluoperazine on intracellular Ca2+ concentration in rat macrophages has been investigated. We have shown for the first time that trifluoperazine causes dose-dependent intracellular Ca2+ concentration increase due to Ca2+ mobilization from intracellular Ca2+ stores and subsequent Ca2+ entry in rat peritoneal macrophages. It has been also established that inhibitors of phospholipase A2 (4-bromophenacyl bromide, prednisolone and dexamethasone), cyclooxygenases (aspirin and indo-methacin) and lipoxygenases (caffeic acid, zileuton and baicalein) attenuate trifluoperazine-induced Ca2+ responses in rat macrophages. The data obtained suggest the involvement of the enzymes and (or) products of the arachidonic acid metabolism in the trifluoperazine effect on the intracellular Ca2+ concentration in rat peritoneal macrophages.