The effects of lithium on the functions of human neutrophils and lymphocytes in vitro and in vivo.

The effects of lithium sulphate (LiSO4) at concentrations ranging from 10(-7)M to 10(-2)M on human polymorphonuclear leucocyte (PMNL) and lymphocyte functions in vitro were investigated. The leucocyte function assessed were PMNL motility, post-phagocytic hexose-monophosphate shunt activity, myeloperoxidase-mediated iodination of Candida albicans and lymphocyte transformation to mitogens. These same functions as well as the results of serological studies were assessed in normal volunteers prior to ingestion of lithium carbonate (LiCO3), 2 hours and 24 hours after the ingestion of a single oral dose of 480 mg LiCO3, and on the 4th day of ingestion of 2 X 480 mg LiCO3 tablets daily. Incubation of PMNL with LiSO4 at concentrations up to 10(-3)M had no detectable effects on motility or post-phagocytic metabolic activity. Higher concentrations (10(-3)M) inhibited these functions. Likewise, at concentrations up to 1 X 10(-4)M LiSO4 had no effects on mitogen-induced transformation of lymphocytes, although higher concentrations did inhibit this activity. These same leucocyte functions were unaffected by ingestion of LiCO3. Levels of serum immunoglobulins and complement components, total haemolytic complement activity and salivary IgA values also remained unaltered. In vitro investigations showed that at a concentration of 10(-3)M LiSO4 had no inhibitory effects on the stimulation of PMNL motility mediated by ascorbate, levamisole and thiamine.