LEUKOCYTE TRANSMEMBRANE POTENTIAL IN BIPOLAR ILLNESS

Abnormalities in ion regulation and distribution are commonly reported in bipolar disorder. In an effort to determine if these alter cellula r physiological function, we determined the transmembrane potential (T MP) in mononuclear leukocytes from normal individuals and patients wit h bipolar illness either during normal phase or manic and hypomanic ep isodes. TMP was analyzed by flow cytometry using dihexyloxacarbocyanin e iodide (DIOC6(3)), a cationic potential sensitive fluorescent dye. A normal range was established from measurements on leukocytes from 5 c ontrol individuals. TMP of manic and hypomanic patients was significan tly hyperpolarized (P = 0.0036). The TMP of euthymic bipolar individua ls was not different from normal controls. Pathologic moods in bipolar illness may be associated with altered cellular membrane physiology.