title: Substance P and neurokinin A are codistributed and colocalized in the porcine gastrointestinal tract.
abstract: Immunoreactive substance P and neurokinin A were measured with radioimmunoassay in extracts of different segments of porcine gastrointestinal tract using C-terminally directed antisera. In all segments, the concentrations of substance P and neurokinin A were similar. The largest concentrations of both peptides were found in the mid-colon. By gel chromatography and reversed-phase high pressure liquid chromatography the immunoreactivity in extracts from ileum eluted as homogenous peptides at the positions of synthetic substance P and neurokinin A, respectively. No neurokinin B was found. By immunohistochemistry of porcine duodenum, jejunum, ileum and mid-colon, identical localization patterns were found for substance P and neurokinin A, and the two peptides demonstrated by double immunofluorescence to be colocalized in the enteric nervous system of the ileum. We conclude that the tachykinins substance P and neurokinin A are codistributed and colocalized in the procine gastrointestinal tract and suggest that the two peptides are produced from a common precursor, beta- and/or gamma-preprotachykinin, in the same neurons.
authors.affiliation: Department of Medical Physiology C, Panum Institute, Copenhagen, Denmark.
authors.forename: P
authors.initials: P
authors.lastname: Schmidt
authors.forename: S S
authors.initials: SS
authors.lastname: Poulsen
authors.forename: T N
authors.initials: TN
authors.lastname: Rasmussen
authors.forename: M
authors.initials: M
authors.lastname: Bersani
authors.forename: J J
authors.initials: JJ
authors.lastname: Holst
mesh_terms: D000818:Animals; D004064:Digestive System / Q000737:chemistry* / Q000166:cytology* / Q000294:innervation; D005455:Fluorescent Antibody Technique; D007106:Immune Sera; D009130:Muscle, Smooth / Q000737:chemistry* / Q000166:cytology* / Q000294:innervation; D009197:Myenteric Plexus / Q000737:chemistry / Q000166:cytology; D009412:Nerve Fibers / Q000737:chemistry / Q000648:ultrastructure; D015288:Neurokinin A / Q000032:analysis*; D009928:Organ Specificity; D013373:Substance P / Q000032:analysis*; D013552:Swine
chemical_list: D007106:Immune Sera; D013373:Substance P; D015288:Neurokinin A