Effect of Duodenectomy on Gastric Motility and Gastric Hormones in Dogs

Abstract

ObjectiveTo test the hypothesis that the duodenum is required to coordinate interdigestive insulin secretion with gastrointestinal motility and to determine whether duodenectomy alters the interdigestive cycles of plasma motilin and insulin levels and their relations to insulin secretion and motility. MethodsAdult mongrel dogs were chronically implanted with force transducers in the stomach, duodenum, and upper jejunum to monitor contractile activity. Eight healthy mongrel dogs were divided into control and duodenectomized dogs. Insulin secretion, gastrointestinal motility, and plasma concentrations of motilin during the interdigestive period were measured in normal and duodenectomized dogs. ResultsAfter duodenectomy, no obvious phase III contractions were seen in the gastric antrum, but migrating phase III contractions were seen in the upper jejunum. The plasma motilin concentration did not fluctuate as it does in normal dogs, and remained low. After duodenectomy, insulin secretory cycles were not coordinated with either cycles of interdigestive motility or the plasma concentration of motilin. Exogenous motilin administration stimulated endogenous insulin release significantly compared with saline-treated controls. The contractile response of the stomach to exogenous motilin after duodenectomy was similar to that of intact dogs. ConclusionsDuodenectomy disrupts the relation between cycles of both interdigestive gastrointestinal motility and insulin secretion. These effects of duodenectomy may be attributable to interruption of the duodenopancreatic neural connections, hormonal abnormalities, or loss of vagus-sensitive humoral factors. The duodenum, which stores motilin, seems to play an important role in the relations between gastric migrating motor complexes and the concomitant increase of insulin secretion in fasted dogs. The mechanism responsible for the effect of motilin in both duodenectomized and normal dogs may involve a cholinergic pathway.The duodenum occupies a strategic anatomical position in the upper digestive tract and is intimately involved in the coordination of various functions of the upper gut. It influences gastric empting, 1 pancreatic and biliary secretion, 2 and the organization and initiation of gastric motor patterns 3,4 by invoking hormonal and neural mechanisms. Others have confirmed these findings.5-7 Tanaka and Sarr 8 reported that duodenectomy disrupts not only the coordination of gastric and intestinal migrating motor complexes (MMC) but also the coordination between interdigestive motility and pancreatic secretion, and it abolishes the interdigestive cyclic variations in plasma motilin and pancreatic polypeptide (PP) levels. 9 The release of PP appears to be regulated by a complex interplay between neural input (from the vagus) and humoral factors that originate from the upper gut. 10,11The duodenum also plays an important role by regulating the release of certain pancreatic hormones. For example, intraduodenal glucose administration causes the release of more insulin than does...

Endogenous ghrelin and 5-HT regulate interdigestive gastrointestinal contractions in conscious rats

“…Phase III contractions in the small intestine are independent of plasma motilin concentration (47). Motilin antiserum inhibits the occurrence of phase III contractions only in the stomach (38,50). Acute vagal nerve blockade abolished gastric phase III without affecting intestinal phase III in dogs (29).…”

“…After duodenectomy, no obvious phase III contractions were seen in the antrum, but migrating phase III contractions were seen in the upper jejunum in dogs (50). Gastric phase III is vagal dependent, whereas intestinal phase III is vagal independent in dogs (33).…”

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“…The results of several other studies lend support to this theory [16,27,33,[74][75][76][77] . An in-depth analysis of the physiolog y of the mechanism underlying the occurrence of DGE has also been reported, showing that the initiation of interdigestive phase Ⅲ is closely related to the elevation of plasma motilin concentration [78] . Motilin, a 22-aminoacid residue polypeptide, originates in motilin cells, which are scattered in the duodenal epithelium [78] .…”

Prevention of gastrostasis after pancreaticoduodenal resection: new technique of gastroenterostomy

“…Важное значение в обеспечении моторики же-лудка имеет мотилин -полипептид, состоящий из 22 аминокислот, вырабатываемый Мо-клетками, разбросанными в эпителии двенадцатиперстной кишки [42]. Эритромицин и другие макролиды, имеющие в своем составе 14-членное лактонное кольцо, действуют, как агонисты мотилина, спо-собствуют разрешению гастростаза.…”

“…It is a polypeptide including 22 amino acids which are produced by M-cells of duodenal epithelium [42]. Erythromycin and other macrolide with 14-membered lactone ring effect as motilin's agonists providing gastrostasis resolving.…”