Intracellular calcium signalling in peripheral cells of patients with bipolar affective disorder

Consistent with previous studies, elevated free intracellular calcium ion concentrations ([Ca²⁺]_i) were found in blood platelets and lymphocytes of patients with mania and bipolar depression. Incubation with an ultrafiltrate of plasma from patients with bipolar illness had no effect on intracellular calcium ion concentration in platelets from normal subjects, suggesting that elevated [Ca²⁺]_i is not due to a circulating factor. As was true in an earlier study of the effect of lithium on platelets, incubation with therapeutic levels of carbamazepine lowered [Ca²⁺]_i in lymhocytes from affectively ill patients but not controls. Increased [Ca²⁺]_i in peripheral cells may reflect a diffuse change in cellular homeostasis and may contribute to mixtures as well as rapid alternations of activity of affective, behavioral and physiologic systems in bipolar illness. Correction of the abnormality may at least be a marker of a relevant therapeutic action if it is not the action itself.