Water-avoidance stress enhances gastric contractions in freely moving conscious rats: role of peripheral CRF receptors

• Published in: Journal of gastroenterology Vol. 49; no. 5; pp. 799 - 805
• Main Authors: Nozu, Tsukasa, Kumei, Shima, Takakusaki, Kaoru, Okumura, Toshikatsu
• Format: Journal Article
• Language: English
• Published: Tokyo Springer Japan 01.05.2014; Springer; Springer Nature B.V
• Subjects: Abdominal Surgery; ACTH; Animals; Colorectal Surgery; Corticotropin releasing hormone; Corticotropin-Releasing Hormone - pharmacology; Gastric Emptying - physiology; Gastroenterology; Gastrointestinal Motility - physiology; Hepatology; Male; Manometry; Medicine; Medicine & Public Health; Muscle Contraction - physiology; Original Article—Alimentary Tract; Peptide Fragments - pharmacology; Peptides, Cyclic - pharmacology; Rats; Rats, Sprague-Dawley; Receptors, Corticotropin-Releasing Hormone - drug effects; Receptors, Corticotropin-Releasing Hormone - metabolism; Signal Transduction - physiology; Stomach - metabolism; Stress, Psychological - metabolism; Surgical Oncology; Urocortins - pharmacology; Water; CRF receptor type 1; Gastric emptying; Gastric contractions; Stress; Intraluminal gastric pressure
• ISSN: 0944-1174; 1435-5922
• DOI: 10.1007/s00535-013-0828-8

Background Stress alters gastrointestinal motility through central and peripheral corticotropin-releasing factor (CRF) pathways. Accumulating evidence has demonstrated that peripheral CRF is deeply involved in the regulation of gastric motility, and enhances gastric contractions through CRF receptor type 1 (CRF1) and delays gastric emptying (GE) through CRF receptor type 2 (CRF2). Since little is known whether water-avoidance stress (WAS) alters gastric motility, the present study tried to clarify this question and the involvement of peripheral CRF receptor subtypes in the mechanisms. Methods We recorded intraluminal gastric pressure waves using a perfused manometric method. The rats were anesthetized and the manometric catheter was inserted into the stomach 4–6 days before the experiments. We assessed the area under the manometric trace as the motor index (MI), and compared this result with those obtained 1 h before and after initiation of WAS in nonfasted conscious rats. Solid GE for 1 h was also measured. Results WAS significantly increased gastric contractions. Intraperitoneal (ip) administration of astressin (100 μg/kg, 5 min prior to stress), a nonselective CRF antagonist, blocked the response to WAS. On the other hand, pretreatment (5 min prior to stress) with neither astressin2-B (200 μg/kg, ip), a selective CRF2 antagonist, nor urocortin 2 (30 μg/kg, ip), a selective CRF2 agonist, modified the response to WAS. These drugs did not alter the basal MI. WAS did not change GE. Conclusions WAS may activate peripheral CRF1 but not CRF2 signaling and stimulates gastric contractions without altering GE.