Neuromedin U octapeptide alters ion transport in porcine jejunum.
The gut neuropeptide, neuromedin U octapeptide (NMU-8) produced transient elevations in short-circuit current (EC50 = 0.7 nmol/l) after its contraluminal administration to sheets of porcine distal jejunal mucosa in vitro. Mucosal responses to NMU-8 were unaffected by 1 mumol/l atropine or hexamethonium, but were abolished by tetrodotoxin (0.1 mumol/l), dependent upon extracellular Cl, and underwent tachyphylaxis upon repeated peptide application. NMU-8 did not affect contractility of isolated jejunal longitudinal muscle. Thus, NMU-8 appears to selectively modify intestinal ion transport through interactions with non-cholinergic enteric neurons.
Brown
D R
DR
University of Minnesota, College of Veterinary Medicine, Department of Veterinary Biology, St. Paul 55108.
Quito
F L
FL
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001693:Biological Transport, Active / Q000187:drug effects; D005260:Female; D006584:Hexamethonium Compounds / Q000494:pharmacology; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism; D007477:Ions / Q000378:metabolism; D007583:Jejunum / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009479:Neuropeptides / Q000494:pharmacology*; D013552:Swine; D013618:Tachyphylaxis / Q000187:drug effects; D013779:Tetrodotoxin / Q000494:pharmacology
D006584:Hexamethonium Compounds; D007477:Ions; D009479:Neuropeptides; D013779:Tetrodotoxin; D001285:Atropine; C046270:neuromedin U 8