Glucocorticoid receptors in lymphocytes in anorexia nervosa

The aim was to explore the down-regulation of the glucocorticoid receptors during hypercortisolaemia in anorexia nervosa.

Urine and plasma samples were obtained for cortisol determination and blood lymphocytes were isolated for receptor binding studies.

Sixteen anorexic patients, aged 16-27 years, with a mean +/- SEM body mass index of 14.2 +/- 2.0 (ranging from 11.1 to 17.4), and 15 normal women were studied. Six patients were reinvestigated after a significant weight gain.

The binding capacity and affinity of the glucocorticoid receptors were measured with dexamethasone as ligand on lymphocytes.

In patients, both total and free plasma cortisol concentrations were higher than in the normal women, as was their urinary free cortisol; the number of glucocorticoid receptors per cell (Ro) and the binding affinity (Kd) for dexamethasone were, however, not significantly different (Ro: 7687 +/- 1750 vs 7347 +/- 1285 sites/cell; Kd: 7.7 +/- 2.4 vs 7.4 +/- 1.7 nM at 24 degrees C). After weight gain (14 +/- 2 to 16 +/- 2 kg/m2), receptor numbers were 8421 +/- 2126 (pre) and 9011 +/- 500 (post) sites/cell, which are not significantly different (P greater than 0.2); the Kd was unchanged (9.3 +/- 2.6 vs 9.2 +/- 2.4 nM). CONCLUSIONS Hypercortisolaemia does not down-regulate the lymphocyte glucocorticoid receptors in anorexia nervosa and a post-receptor defect might be involved in peripheral tissue resistance to the effects of glucocorticoid hormones in undernutrition.