title: Effect of chronic stress on gastric emptying and plasma ghrelin levels in rats.
abstract: Chronic stress is associated with gastrointestinal functional diseases. Although the pathophysiology seems to be associated with gastrointestinal motility, their mechanisms remain unclear. We investigated gastric emptying and chemical mediators under conditions of continuous stress, which were produced using 8-week-old male Wistar rats kept in a cage filled with water to 2 cm height for 5 days. We examined gastric emptying by the phenol red method and chemical mediators at 4, 8, and 24 h and 3 and 5 days after initiation of stress restraint. Plasma ACTH level was significantly higher in the stress throughout the period of measurement. Continuous stress delayed gastric emptying until 24 h: peak delay was observed at 8 h, whereas gastric emptying was accelerated on days 3 and 5. Plasma noradrenalin level was significantly elevated at every time point until 24 h. Guanethidine pretreatment eliminated the delay in gastric emptying at 8 h. Active ghrelin was significantly increased on days 3 and 5 after peak (at 24 h) plasma total and desacyl ghrelin in the stress group. Number of ghrelin-immunoreactive cells and level of preproghrelin mRNA expression in the gastric body increased in parallel with plasma active ghrelin level. Pretreatment with growth hormone secretagogue receptor antagonist at 5 days partially inhibited the stress-induced acceleration of gastric emptying. Delayed gastric emptying at acute phase of continuous stress was mediated via sympathetic pathway, while acceleration at chronic phase was mediated via increased active ghrelin release from the stomach.
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ochi
authors.forename: Kazunari
authors.initials: K
authors.lastname: Tominaga
authors.forename: Fumio
authors.initials: F
authors.lastname: Tanaka
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tanigawa
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Shiba
authors.forename: Toshio
authors.initials: T
authors.lastname: Watanabe
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: Nobuhide
authors.initials: N
authors.lastname: Oshitani
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Higuchi
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Arakawa
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D002395:Catecholamines / Q000097:blood; D002908:Chronic Disease; D005746:Gastric Emptying / Q000502:physiology*; D005753:Gastric Mucosa / Q000378:metabolism; D054439:Ghrelin / Q000097:blood*; D006145:Guanethidine / Q000494:pharmacology; D007150:Immunohistochemistry; D008297:Male; D009929:Organ Size / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D054440:Receptors, Ghrelin / Q000037:antagonists & inhibitors; D012149:Restraint, Physical; D013270:Stomach / Q000187:drug effects; D013315:Stress, Psychological / Q000097:blood / Q000503:physiopathology*; D013565:Sympatholytics / Q000494:pharmacology
chemical_list: D002395:Catecholamines; D054439:Ghrelin; D012333:RNA, Messenger; D054440:Receptors, Ghrelin; D013565:Sympatholytics; D000324:Adrenocorticotropic Hormone; D006145:Guanethidine