title: High-affinity substance P binding sites in rat esophagus plexus submucosus.
abstract: Substance P receptors were investigated in rat esophagus using 125I-Bolton-Hunter substance P as a labeling probe. Autoradiographic studies show that esophageal submucosa contains clusters of high-affinity substance P binding sites [maximum binding (Bmax) 4.2 +/- 0.28 fmol/mg protein; dissociation constant (Kd) 0.1 +/- 0.01 X 10(9) M]. The receptor distribution pattern is typical for submucous neurons. These data suggest that substance P may act as a neurotransmitter in rat esophagus.
mesh_terms: D000818:Animals; D001345:Autoradiography; D001665:Binding Sites; D004947:Esophagus / Q000294:innervation*; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013368:Submucous Plexus / Q000098:blood supply / Q000378:metabolism*; D013373:Substance P / Q000378:metabolism*
chemical_list: D013373:Substance P