Characteristic motor activity of the gastrointestinal tract in fasted conscious dogs measured by implanted force transducers

Abstract

Gastrointestinal contractile actiivity from the gastric body to the terminal ileum in conscious dogs was continuously recorded for several weeks by means of chronically implanted strain-gage force transducers. It was found that the 24-hr changes in the gastrointestinal contractile activity consisted of the two different major patterns, the digestive and interdigestive patterns. In the interdigestive state, a cyclic, recurring, caudad-moving band of strong contractions starting in the stomach and the duodenum and traversing the entire length of the small intestine was observed. When one band of strong contractions reached the distal ileum, another developed in the stomach and the duodenum again and propagated in a caudad direction. Such recycling episodes interrupted by long-lasting quiescence repeatedly occurred until the next meal. These characteristic contractile activities observed in our dogs are identical with the interdigestive myoelectric complex of the stomach and the small bowel recently reported by Code and Marlett (5). Four sequential phases (I-IV) of the migrating myoelectric complex, defined in terms of action potential activity, seem to correspond to the resting (quiescence), preceding irregular contractions, strong contractions, and subsiding contractions observed in the present study, respectively. Function and control mechanism of the interdigestive contractile activity were discussed.

Effect of muscarinic blocker on enhancing the action of fructus aurantii immaturus on intestinal myoelectric activity in dogs

“…Gastrointestinal contractile activities are identical to the MMC. Four sequential phases (Ⅰ-Ⅳ) of MMC, defined in terms of action potential activity, appear to correspond to the resting (quiescence), preceding irregular, strong, and subsiding contractions [4] . Smooth muscle cells may suddenly discharge one or more action potentials under the condition of depolarization.…”

Plasma somatostatin-like immunoreactivity during the interdigestive period in the dog.

“…These include increased levels ofplasma motilin (19)(20)(21)(22) and pancreatic polypeptide (22), and Plasma Somnatostatin-like Immunoreactivity durinig Itnterdigestive Period increased secretion of gastric acid (23), pancreatic enzymes and bile (22,24). There is a simultaneous occurrence of interdigestive duodenal contractions that migrate aborally along the whole intestine as a strong band (3,5), increasing the intestinal flow rate (25). Therefore the interdigestive phase is a period ofchange in endocrine, exocrine, and muscular activities of the digestive system.…”

“…In the fasted state the human (1, 2) and canine (3)(4)(5) gastrointestinal tract exhibits a type of motor activity called the "interdigestive contractions" or "phase III" of the interdigestive myoelectric complex. The contractions are observed only in the conscious state and occur after a post-prandial interval the length of Dr. Unger is a Senior Medical Investigator, Veterans Administration.…”

“…They have a fixed duration and they recur at regular intervals (3,4). Duodenal interdigestive contractions occur simultaneously with those of the stomach and migrate aborally along the small intestine to the terminal ileum (3,5).…”

Intragastric Dai-Kenchu-To, a Japanese Herbal Medicine, Stimulates Colonic Motility via Transient Receptor Potential Cation Channel Subfamily V Member 1 in Dogs

“…Seventy mL of 154 mM NaCl solution (Otsuka Pharmaceutical Factory, Inc., Tokushima, Japan) containing a powdered extract of DKT (2.5 or 5 g) was administered as a bolus into the gastric lumen through the silicone catheter, when all colonic transducers were in the quiescent period and when ileal contractile activity showed fasted pattern, in order to study the effects of intragastric DKT on colonic motility and defecation. Transducers on the ileum were used to assure that ileal contractile activity exhibited cyclic occurrence of contractions and quiescent period specific to the fasted pattern (Itoh et al 1978). A powdered extract of DKT consisted of 50% dried ginger rhizome, 30% ginseng root, and 20% zanthoxylum fruit.…”