Responsiveness to stress in major depression

Abstract

In an investigation of cation transport in bipolar affective disorder, we have measmed parameters related to Na,K-ATPase, the enzyme that carties out active transport of sodium and potassium, in lymphoblastoid cells cultured from patients with bipolar affective disorder, age-matched nonaffected family relatives, and unrelated controls. Patients and their relafives were from well.characterized pedigrees of Old Order Amish. The use of iymphoblastoid cell lines largely eliminated possible effects of factom such as clinical state or recent drug treatment. Patients had lower ion mmsport per cell (271:1:40 pmol/10 e cells-min for patients vs 490 + 107 for related controls and 396 + 79 for unrelated controls; pc 0.001 by Kmskal-Wallis test) and per mmsport enzyme site (reduced by about 35% in patients, pc 0.02) than did related or unrelated controls. These data suggest that abnormally regulated ion transport may be associated with bipolar affective disorder independently of clinical state.