A novel method to assess gastric accommodation and peristaltic motility in conscious rats

Objective. To simultaneously study gastric accommodation and peristaltic motility in the whole stomach of conscious rats by measuring intragastric pressure (IGP) during test-meal infusion. Material and methods.After an overnight fast, a test-meal infusion system and a catheter to measure IGP were connected to a chronically implanted gastric fistula. IGP was measured during infusion of an X-ray-opaque, non-nutritious viscous test meal (0.25–2 ml min−1); gastric motility and emptying were assessed by X-ray fluoroscopy. Peristaltic motility-induced IGP waves were quantified as a motility index (wave amplitude divided by wavelength). Experiments were performed in Sprague-Dawley (SD) rats and in the high-anxiety Wistar Kyoto (WKY) rats. Moreover, the effects of 30 mg kg−1 NG-nitro-L-arginine methyl ester (L-NAME), 1 mg kg−1 atropine or 20 mg kg−1 molsidomine were tested in SD rats. Results. Compared with SD rats, IGP increased significantly faster during stomach distension in WKY rats, indicating impaired acco...