title: Evidence for tachykinin NK3 receptors-triggered peptide YY release from isolated guinea-pig distal colon.
abstract: The anorectic gut hormone, peptide YY (PYY), is released from colonic mucosal endocrine cells, but little is known about the role for tachykinin NK3 receptor in the control of PYY release from the colonic mucosa. We investigated the functional role for NK3 receptors in the control of PYY release from isolated guinea-pig distal colon, and the role for NK3 receptors-triggered PYY release in the control of colonic motility. Isolated colonic preparations were mounted in organ baths for measurement of PYY release and mechanical activity. The release of PYY from these preparations was determined by enzyme immunoassays. The NK3 receptor agonist senktide produced a tetrodotoxin/atropine-sensitive sustained increase in the release of PYY from the colonic preparations. Basal PYY release was transiently inhibited by the NK3 receptor antagonist SB222200. The neuropeptide Y1 receptor antagonist BIBO3304 produced a leftward shift of the concentration-response curves for senktide-evoked neurogenic contraction, but neither the neuropeptide Y2 receptor antagonist BIIE0246 nor the neuropeptide Y5 receptor antagonist CGP71683 affected the senktide concentration-response curves. NK3 receptors appear to play an important role in the control of PYY release from colonic mucosa, and NK3 receptor-triggered PYY release can exert Y1 receptor-mediated inhibition of tachykinergic neuromuscular transmission. This indicates a pathophysiological role for the NK3 receptor-triggered PYY release in the control of colonic motility.
authors.affiliation: Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Mibu, Tochigi 321-0293, Japan. Electronic address: s-kojima@dokkyomed.ac.jp.
authors.forename: Shu-ichi
authors.initials: S
authors.lastname: Kojima
authors.affiliation: Laboratory of Experimetal Animal Science Nippon Veterinary and Life Science University School of Medicine, 1-7-1 Kyonan-cho, Musashino, Tokyo 180-8602, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tohei
authors.affiliation: Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Mibu, Tochigi 321-0293, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Kojima
authors.affiliation: Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Mibu, Tochigi 321-0293, Japan.
authors.forename: Naohiko
authors.initials: N
authors.lastname: Anzai
mesh_terms: D000818:Animals; D003106:Colon / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D006168:Guinea Pigs; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D010446:Peptide Fragments / Q000494:pharmacology; D019894:Peptide YY / Q000378:metabolism*; D018042:Receptors, Neurokinin-3 / Q000819:agonists / Q000502:physiology*; D013373:Substance P / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D010446:Peptide Fragments; D018042:Receptors, Neurokinin-3; C054724:senktide; D019894:Peptide YY; D013373:Substance P
keywords: Colon; NK(3) receptor; Neuropeptide Y(1) receptor; Peptide YY release; Tachykinin