title: Somatostatin sst(2) receptors inhibit peristalsis in the rat and mouse jejunum.
abstract: Somatostatin [somatotropin release-inhibitory factor (SRIF)] has widespread actions throughout the gastrointestinal tract, but the receptor mechanisms involved are not fully characterized. We have examined the effect of selective SRIF-receptor ligands on intestinal peristalsis by studying migrating motor complexes (MMCs) in isolated segments of jejunum from rats, mice, and sst(2)-receptor knockout mice. MMCs were recorded in 4- to 5-cm segments of jejunum mounted horizontally in vitro. MMCs occurred in rat and mouse jejunum with intervals of 104.4 +/- 10 and 131.2 +/- 8 s, respectively. SRIF, octreotide, and BIM-23027 increased the interval between MMCs, an effect fully or partially antagonized by the sst(2)-receptor antagonist Cyanamid154806. A non-sst(2) receptor-mediated component was evident in mouse as confirmed by the observation of an inhibitory action of SRIF in sst(2) knockout tissue. Blocking nitric oxide generation abolished the response to SRIF in rat but not mouse jejunum. sst(2) Receptors mediate inhibition of peristalsis in both rat and mouse jejunum, but a non-sst(2) component also exists in the mouse. Nitrergic mechanisms are differentially involved in rat and mouse jejunum.
authors.affiliation: Department of Biomedical Science, Alfred Denny Building, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
authors.forename: Faiza
authors.initials: F
authors.lastname: Abdu
authors.forename: Gareth A
authors.initials: GA
authors.lastname: Hicks
authors.forename: Grant
authors.initials: G
authors.lastname: Hennig
authors.forename: Jeremy P
authors.initials: JP
authors.lastname: Allen
authors.forename: David
authors.initials: D
authors.lastname: Grundy
mesh_terms: D000818:Animals; D001285:Atropine / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D007583:Jejunum / Q000294:innervation / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009119:Muscle Contraction / Q000187:drug effects; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009543:Nifedipine / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D015282:Octreotide / Q000494:pharmacology; D010456:Peptides, Cyclic / Q000494:pharmacology; D010528:Peristalsis / Q000502:physiology*; D011312:Pressure; D051381:Rats; D017481:Receptors, Somatostatin / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D013004:Somatostatin / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology; D020960:omega-Conotoxins / Q000494:pharmacology
chemical_list: C091738:BIM 23027; D004791:Enzyme Inhibitors; D010456:Peptides, Cyclic; D017481:Receptors, Somatostatin; D020960:omega-Conotoxins; D013779:Tetrodotoxin; D013004:Somatostatin; D001285:Atropine; C093733:somatostatin receptor 2; D019001:Nitric Oxide Synthase; D009543:Nifedipine; D015282:Octreotide; D019331:NG-Nitroarginine Methyl Ester