Neuropeptide Y immunoreactivity in human cerebrospinal fluid.

Neuropeptide Y (NPY) immunoreactivity has been determined in human cerebrospinal fluid (CSF). High pressure liquid chromatography revealed that the NPY immunoreactivity co-eluted with authentic NPY. The range of NPY levels was 108 +/- 18 pg/ml (mean +/- S.D.) in a group of 28 normal subjects. In five additional subjects NPY immunoreactivity was measured in 4 sequential 8 ml aliquots of CSF to determine whether a rostro-caudal gradient was present. No significant differences in NPY levels were detected between any of the 4 aliquots.