Diminished [3H] ouabain binding and 86Rb influx by leukocytes in anorexia nervosa

Leukocyte Na-K ATPase was assessed in ten patients with anorexia nervosa. The indices of Na-K ATPase measured were 86Rb influx and [3H]-ouabain binding. Both 86Rb influx and [3H]-ouabain binding were significantly lower in patients with anorexia nervosa than in controls. Following weight gain (4.1 to 11.9 kg) in seven patients both 86Rb influx and [3H]-ouabain binding increased in each patient to levels similar to those in controls, although the patients still remained underweight. Acute oral glucose challenge (75 g) also resulted in an increase in 86Rb influx and [3H]-ouabain binding in each of the eight patients tested. There was a significant correlation between 86Rb influx and [3H]-ouabain binding. We conclude that the leukocytes of patients with anorexia nervosa have a significantly diminished number of Na-K ATPase units with a parallel decrease in 86Rb influx. Weight gain and acute glucose challenge result in an increase in both indices of Na-K ATPase. Nutrition appears to play an important role in the modulation of this enzyme.