Cerebrospinal fluid peptide YY immunoreactivity in eating disorders

Peptide YY (PYY), a recently discovered peptide, is a potent stimulant of eating behavior in rats. We developed a radioimmunoassay for PYY and measured cerebrospinal fluid (CSF) levels in subjects with anorexia nervosa, bulimia and matched normal controls. Bulimics who had abstained from bingeing for 30 days showed a dramatic increase in CSF PYY levels compared to normal values (p less than 0.001) or their own values when actively bingeing (p less than 0.01, paired t test). No differences were seen for anorexia nervosa. These results suggest that bulimic behavior may correct a central nervous system abnormality in PYY.