Effects of gastrointestinal hormones and their related compounds on gastric motility in the rat

摘要

We examined the effects of certain gastrointestinal hormones on gastric motility using rat stomach preparatios in vivo. Changes of water level caused by the movement of the stomach which was filled with saline were recorded. Single injections of cholecystokinin (1, 2 and 4 μg/kg) induced relaxation of the stomach. Single injections of bombesin in low doses (below 0.2 μg/kg) induced relaxation and in high doses (over 0.2 μg/kg) contraction after brief relaxation. Single injections of neurotensin (1, 2, 4 and 8 μg/kg), somatostatin (5, 10 and 20μg/kg) and substance P (1, 2, 4 and 8 μg/kg) induced relaxation followed by contraction, but their dose-response relations were obscure. Infusions of neurotensin (1, 5 and 25 μg/kg/h) and somatostatin (2.5 and 5 μg/kg/h) enhanced the stomach tension, whereas substance P (1, 5 and 25 μg/kg/h) reduced it. Single injections and infusions of neurotensin, somatostatin or substance P showed different effects on gastric motility. On the other hand, Met-enkephalin (1, 10 and 100 μg/kg) and porcine motilin (1, 10 and 100 μg/kg) did not affect gastric motility in our rat stomach preparations. These results suggest that some gastrointestinal hormones take part in stomach movements.