Erythrocyte membrane cation carrier in depressive illness.

Erythrocyte sodium concentration, potassium concentration, Na-K ATPase activity, and ouabain sensitive potassium influx were determined in female inpatients suffering from a depressive illness. In most patients the biochemical values were also determined shortly before the patient's discharge from hospital. The Na-K ATPase and the ouabain sensitive potassium influx increased significantly with improvement in the depressive mood rating.