Neuropeptide Y is a peptide belonging to the PP-family and occurs in neurons and adrenal medullary cells. The brain contains large quantities of NPY and it is also found in the peripheral nervous system, where it coexists with noradrenaline in sympathetic fibers. NPY inhibits gut motility and causes vasoconstriction. Pheochromocytomas contain NPY.
Absorption with 10-100 μg NPY 1-20 per ml diluted antiserum abolishes the staining, while PYY and PP do not.
Positive control: Stefanini-fixed sections of rat small intestine