title: Comparison of stress-induced modulation of smooth-muscle activity between ileum and colon in male rats.
abstract: Stress is a well-known cause of numerous digestive conditions, including gastrointestinal-function disorders. The autonomic nervous system regulates intestinal movements via cholinergic and adrenergic efferent fibers; however it is not clear how stress could affect these control mechanisms and in particular whether in a site-dependent manner. In this study we tested in vitro the effects of topical application of acetylcholine (Ach) and adrenalin (Adr) on smooth-muscle contractions of intestinal segments isolated from stress-conditioned rats. Stress was loaded by hypergravity stimulation (10min/day) for periods of 1, 6 or 30days. As a result, stress-conditioning affected intestinal sensitivity to Ach and Adr differently at sections of the ileum and colon. In the ileum no significant differences were found between control and stress-conditioned rats, whereas in the colon, samples from 6- and 30-day stress-conditioned rats showed larger amplitudes of Ach-induced contraction, as well as greater antagonization by Adr application. These results suggest that stress conditioning can modify autonomic control of intestinal movements by altering smooth-muscle sensitivity to Ach and Adr.
authors: Physiological Laboratories, Japan Women's University, Tokyo, Japan.
authors: Mari
authors: M
authors: Kimoto
authors: University of Brasilia, Brasilia, Brazil; Integrative Sensory Physiology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
authors: Jorge L
authors: JL
authors: Zeredo
authors: Laboratory of Biochemistry and Food Biology, Japan Women's University, Tokyo, Japan.
authors: Masato S
authors: MS
authors: Ota
authors: Integrative Sensory Physiology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
authors: Zenro
authors: Z
authors: Nihei
authors: Physiological Laboratories, Japan Women's University, Tokyo, Japan; Integrative Sensory Physiology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan. Electronic address: k-toda@nagasaki-u.ac.jp.
authors: Kazuo
authors: K
authors: Toda
mesh_terms: D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D003106:Colon / Q000503:physiopathology*; D004195:Disease Models, Animal; D004837:Epinephrine / Q000378:metabolism; D018471:Hypergravity; D007082:Ileum / Q000503:physiopathology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D009130:Muscle, Smooth / Q000503:physiopathology*; D017208:Rats, Wistar; D013315:Stress, Psychological / Q000503:physiopathology*; D013997:Time Factors
chemical_list: D000109:Acetylcholine; D004837:Epinephrine
keywords: Acetylcholine; Adrenaline; Digestion; In vitro; Rat; Smooth muscle