title: 5-HT4 receptor enhances the propulsive power of the peristaltic reflex in the rat distal colon.
abstract: The present study was designed to investigate the nature of the 5-HT4 receptors affecting the peristaltic reflex in the isolated rat distal colon. A single peristaltic reflex was evoked by infusing Tyrode solution into the lumen of the isolated segment using our modified Trendelenburg's method under an isovolumic condition. A 5-HT4 receptor agonist, mosapride (10 nM), did not affect the threshold pressure and the propagation distance of the reflex contraction, but significantly increased the developed pressure (maximum pressure - threshold pressure) from 19.1 +/- 11.8 cm H2O in the control to 26.8 +/- 13.0 cm H2O (n = 8, P<0.05) without affecting the resting muscle tone in the distal colon. The present result suggests that stimulation of 5-HT4 receptor enhances the propulsive power to move the luminal contents in the rat distal colon.
authors.affiliation: Department of Physiology II, Nara Medical University, Kashihara, Japan. makotok@naramed-u.ac.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Kadowaki
authors.forename: Xia Obiao
authors.initials: XO
authors.lastname: Wang
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Shimatani
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yoneda
authors.forename: Miyako
authors.initials: M
authors.lastname: Takaki
mesh_terms: D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D003106:Colon / Q000294:innervation* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D017615:Enteric Nervous System / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009025:Morpholines / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009129:Muscle Tonus / Q000187:drug effects / Q000502:physiology; D009130:Muscle, Smooth / Q000187:drug effects / Q000294:innervation / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010528:Peristalsis / Q000187:drug effects / Q000502:physiology*; D011312:Pressure; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism*; D044422:Receptors, Serotonin, 5-HT4; D012026:Reflex, Stretch / Q000187:drug effects / Q000502:physiology; D012701:Serotonin / Q000378:metabolism*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
chemical_list: D001549:Benzamides; D009025:Morpholines; D011985:Receptors, Serotonin; D017366:Serotonin Receptor Agonists; D044422:Receptors, Serotonin, 5-HT4; D012701:Serotonin; C062720:mosapride