Elevated plasma immunoreactive beta-endorphin in anorexia nervosa.

Basal morning plasma levels of immunoreactive-beta-endorphin (ir-beta-EP), and 17-beta estradiol (E2) were assessed in 25 adolescents with anorexia nervosa (AN) in comparison to 24 healthy controls. All subjects were drug free for at least 6 weeks. The mean plasma level of ir-beta-EP was significantly higher (84%) in the AN patients when compared with the control subjects. The elevated plasma ir-beta-EP may be relevant to the suppression of appetite, tolerance of fasting, and to the hypothalamic hypogonadism in AN.