title: PHI-like immunoreactivity in the gallbladder and in vitro effect of porcine PHI on smooth muscle of the gallbladder.
abstract: The occurrence and distribution of PHI-like immunoreactivity in the guinea pig gallbladder has been analysed by radioimmunoassay and immunocytochemistry. Chromatography of gallbladder extracts by gel permeation and high-performance liquid chromatography revealed that guinea pig PHI-like immunoreactivity is of a similar size to that of porcine PHI but may differ in its amino acid sequence. Immunocytochemistry showed PHI-immunoreactivity to be localised to nerves found predominantly in the ganglionated plexus and the mucosal plexus of the gallbladder. Pure natural porcine PHI induced a dose-dependent relaxation of the isolated guinea pig gallbladder muscle which was not blocked by antagonists to acetylcholine, catecholamines, histamine, and 5-hydroxytryptamine. PHI may thus be one of the local factors involved in controlling gallbladder function.
mesh_terms: D000818:Animals; D001652:Bile Ducts / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D005704:Gallbladder / Q000032:analysis / Q000187:drug effects / Q000502:physiology*; D005768:Gastrointestinal Hormones / Q000032:analysis*; D006168:Guinea Pigs; D007118:Immunoassay; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000502:physiology; D010451:Peptide PHI; D010455:Peptides / Q000032:analysis* / Q000494:pharmacology; D013552:Swine
chemical_list: D005768:Gastrointestinal Hormones; D010451:Peptide PHI; D010455:Peptides