Journal of Gastroenterology

, Volume 45, Issue 5, pp 506–514

Mechanism of interdigestive migrating motor complex in conscious dogs

  • Hitoshi Nakajima
  • Erito Mochiki
  • Aaron Zietlow
  • Kirk Ludwig
  • Toku Takahashi
Original Article—Alimentary Tract

DOI: 10.1007/s00535-009-0190-z

Cite this article as:
Nakajima, H., Mochiki, E., Zietlow, A. et al. J Gastroenterol (2010) 45: 506. doi:10.1007/s00535-009-0190-z

Abstract

Background

The migrating motor complex (MMC) is well characterized by the appearance of gastrointestinal contractions in the interdigestive state. This study was designed to clarify the mechanisms of gastric MMC (G-MMC) and intestinal MMC (I-MMC) in conscious dogs.

Methods

Five strain gauge transducers were implanted on the stomach and intestine. To investigate the correlation between luminal 5-HT and phase III contractions, gastric and duodenal juices were collected during the MMC cycle. The 5-HT concentrations in gastric and duodenal juice were measured by HPLC. To investigate whether luminal 5-HT initiates MMC, 5-HT (10−8–10−6 M, 10 ml) was administered into the duodenum 20 min after gastric phase III. To investigate the involvement of 5-HT3 or 5-HT4 receptors in mediating G-MMC and I-MMC, 5-HT3 antagonists (ondansetron) or 5-HT4 antagonists (GR 125,487) were infused for 120 min.

Results

Luminal administration of 5-HT (10−6 M) initiated duodenal phase II followed by G-MMC and I-MMC with a concomitant increased release of plasma motilin. The duodenal 5-HT concentration was significantly increased during phase II (59 ± 9 ng/ml) and phase III (251 ± 21 ng/ml) compared to that of phase I (29 ± 5 ng/ml). On the other hand, the 5-HT content in the stomach was not significantly changed throughout the MMC cycle. Intravenous infusion of motilin (0.3 μg/kg/h) increased the luminal 5-HT content and induced G-MMC and I-MMC. 5-HT4 antagonists significantly inhibited both G-MMC and I-MMC, while 5-HT3 antagonists inhibited only G-MMC.

Conclusion

It is suggested that the MMC cycle is mediated by a positive feedback mechanism via the interaction between motilin and 5-HT.

Keywords

5-HTMotilinGastric MMCIntestinal MMC

Abbreviations

EC cell

Enterochromaffin cell

HPLC

High-performance liquid chromatography

IPAN

Intrinsic primary afferent neurons

MMC

Migrating motor complex

MI

Motility index

RIA

Radioimmunoassay

Copyright information

© Springer 2009

Authors and Affiliations

  • Hitoshi Nakajima
    • 1
    • 2
  • Erito Mochiki
    • 1
  • Aaron Zietlow
    • 2
  • Kirk Ludwig
    • 1
    • 2
  • Toku Takahashi
    • 1
    • 2
    • 3
  1. 1.Department of SurgeryDuke University Medical CenterDurhamUSA
  2. 2.Department of SurgeryMedical College of WisconsinMilwaukeeUSA
  3. 3.Research Service 151Zablocki VA Medical CenterMilwaukeeUSA