title: Effects of neurotensin on the isolated mouse distal colon.
abstract: The effects of neurotensin were studied in the isolated mouse distal colon. This peptide had potent stimulatory effects which were of pre- or postjunctional origin according to the concentrations used. At low concentrations (10(-11)-10(-10) M) neurotensin induced neurogenic non-cholinergic contractions which seemed to result from the release of substance P (or substance P-like activity) by enteric excitatory nerves. At higher concentrations (10(-9)-10(-7) M) neurotensin elicited a biphasic effect consisting of transient relaxation rapidly followed by myogenic contraction. The bee venom toxin apamin inhibited the NT-induced relaxation while inhibition of prostaglandin synthesis by indomethacin abolished the contraction phase. All these responses were tightly related to the extracellular Ca2+ concentration. These properties of neurotensin point to a possible role for this peptide as a modulator of colonic motility.
authors.forename: J
authors.initials: J
authors.lastname: Fontaine
authors.forename: P
authors.initials: P
authors.lastname: Lebrun
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001030:Apamin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D003106:Colon / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005769:Gastrointestinal Motility / Q000187:drug effects; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects; D051379:Mice; D009119:Muscle Contraction / Q000187:drug effects; D009496:Neurotensin / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism; D011453:Prostaglandins / Q000096:biosynthesis; D013373:Substance P / Q000494:pharmacology
chemical_list: D007473:Ion Channels; D011453:Prostaglandins; D001030:Apamin; D013373:Substance P; D009496:Neurotensin; D000109:Acetylcholine; D011188:Potassium; D002118:Calcium