LYMPHOBLASTOID TRANSMEMBRANE POTENTIAL IN BIPOLAR PATIENTS, THEIR SIBLINGS, AND UNRELATED HEALTHY COMPARISON SUBJECTS

Bipolar illness appears to be characterized by alterations in ionic ho meostasis that are related to mood state. This is reflected by reports of altered intracellular sodium and calcium concentrations, altered s odium pump (Na+,K+-adenosine triphosphatase), and calcium pump (Ca2+-a denosine triphosphatase) activity. Recent ex vivo studies with fresh l ymphocytes and in vitro studies with cultured lymphoblasts suggest tha t there may be an enduring trait-related abnormality in Na+,K+-adenosi ne triphosphatase as well. We have previously found that the lymphocyt e transmembrane potential (TMP) varies with mood state. To examine the question of trait-related changes in TMP, we studied TMP of immortali zed lymphoblasts from 14 patients with bipolar illness, nine unaffecte d siblings, and eight normal subjects. TMP was the same in all three g roups. These preliminary data suggest that TMP is a state- rather than a trait-related marker.