title: Ultrastructural evidence for beta-endorphin-like immunoreactivity in the nervous system of the rat duodenum.
abstract: Using a modified immunoelectron microscopic staining technique the opioid peptide beta-endorphin could be demonstrated within large dense-core vesicles (LDVs) which are localized in presumptive axons and dendrites of the duodenal myenteric plexus of the rat duodenum. Pre-absorption tests with synthetic beta-endorphin (10(-6)M, final concentration) abolished the beta-endorphin immunoreactivity, resulting in only beta-endorphin unstained vesicles. To demonstrate more clearly electron-dense beta-endorphin material within vesicles the ultrathin sections were not counterstained with heavy metal salts. These sections revealed that the beta-endorphin material is localized as 'cores' with a mean diameter of 35-50 nm within LDVs corresponding to cores of LDVs, which are 70-90 nm in mean diameter.
authors.forename: H J
authors.initials: HJ
authors.lastname: Wolter
mesh_terms: D000818:Animals; D004386:Duodenum / Q000294:innervation*; D004723:Endorphins / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D008297:Male; D008854:Microscopy, Electron; D009197:Myenteric Plexus / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains; D001615:beta-Endorphin
chemical_list: D004723:Endorphins; D001615:beta-Endorphin