title: High levels of neuropeptide Y in peripheral noradrenergic neurons in various mammals including man.
abstract: Using a highly specific radioimmunoassay for neuropeptide Y (NPY), levels in the peripheral nervous system of guinea-pig, cat, pig and man were measured. In all species very high levels (up to 800 pmol X g-1) were found in sympathetic ganglia and in tissues which receive a dense sympathetic innervation, such as vas deferens, heart atrium, blood vessels and spleen. By immunocytochemistry, NPY-immunoreactive (-IR) principal ganglion cells in sympathetic ganglia and the pelvic plexus were also found to contain dopamine-beta-hydroxylase (DBH) and tyrosine hydroxylase (TH), strongly suggesting that the NPY-IR cells are noradrenergic. NPY- and DBH-IR nerves had a roughly parallel occurrence in the heart, spleen, kidney, respiratory and urogenitary tracts, around blood vessels and within visceral smooth muscle. Considerably more NPY-IR than DBH-IR nerve fibres were seen in the gastrointestinal tract from the oesophagus to the anal sphincter. In addition, NPY-IR local ganglion cells were observed in the submucous and myentric plexuses. NPY-like immunoreactivity was also observed in the adrenal medulla of guinea-pig and cat. NPY thus seems to be a major peptide in the sympathetic nervous system, supporting its proposed role in sympathetic neurotransmission.
mesh_terms: D000818:Animals; D002415:Cats; D005724:Ganglia / Q000032:analysis; D005728:Ganglia, Sympathetic / Q000032:analysis; D006168:Guinea Pigs; D006801:Humans; D008322:Mammals / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000032:analysis*; D009474:Neurons / Q000032:analysis*; D009478:Neuropeptide Y; D009638:Norepinephrine / Q000502:physiology*; D010525:Peripheral Nerves / Q000032:analysis* / Q000166:cytology; D011863:Radioimmunoassay; D013552:Swine
chemical_list: D009419:Nerve Tissue Proteins; D009478:Neuropeptide Y; D009638:Norepinephrine