DECREASED AGONIST-STIMULATED CA2-THERAPY( RESPONSE IN NEUTROPHILS FROM PATIENTS UNDER CHRONIC LITHIUM)

The agonist-stimulated increase in the intracellular concentration of free Ca2+ ([Ca2+](i)) was determined in neutrophils from patients unde r chronic lithium therapy and a control group of age- and sex-matched healthy drug-free subjects. Cells were stimulated with the chemotactic peptide formylmethionylleucylphenylalanin (fMLP) and the Ca2+ concent rations measured with the fluorescent Ca2+ indicator Fura-2. The Ca2response to stimulation with fMLP was significantly attenuated in neut rophils from patients chronically treated with lithium. The data sugge st that lithium treatment inhibits the inositol phospholipid second me ssenger generating system in human cells and support the results of ea rlier inositol phosphate measurements in fMLP-stimulated neutrophils.