THE UP-REGULATION OF NA-ATPASE PUMP NUMBERS IN LYMPHOCYTES FROM THE FIRST-DEGREE UNAFFECTED RELATIVES OF PATIENTS WITH MANIC-DEPRESSIVE PSYCHOSIS IN RESPONSE TO IN-VITRO LITHIUM AND SODIUM ETHACRYNATE(,K+)

Patients with manic depressive disorder (DSM-III-R bipolar disorder) h ave an abnormality of the Na+,K+-ATPase pumps in their lymphocytes: th e pump numbers do not upregulate to stimulation with lithium and ethac rynate. We have now investigated the in vitro adaptive responses of ly mphocyte Na+,K+-ATPase pumps in the first-degree unaffected relatives of patients with a clear history of manic depressive disorder. The lym phocytes of the healthy relatives upregulated their Na+,K+-ATPase pump s normally, suggesting that the abnormal response that we have previou sly observed in patients with the disorder reflects a complex relation between the biochemical phenotype and the development of clinical sym ptoms.