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Mechanism of interdigestive migrating motor complex.

Takahashi T - J Neurogastroenterol Motil (2012)

Bottom Line: Stress is highly associated with the pathogenesis of functional dyspepsia.It has been shown that subset of functional dyspepsia patients show reduced vagal activity and impaired gastric phase III.Thus, maintaining gastric MMC in the interdigestive state is an important factor to prevent the postprandial dyspeptic symptoms.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, Medical College of Wisconsin and Zablocki VA Medical Center, Milwaukee, Wisconsin, USA.

ABSTRACT
Migrating motor complex (MMC) is well characterized by the appearance of gastrointestinal contractions in the interdigestive state. This review article discussed the mechanism of gastrointestinal MMC. Luminal administration of 5-hydroxytryptamine (5-HT) initiates duodenal phase II followed by gastrointestinal phase III with a concomitant increase of plasma motilin release in conscious dogs. Duodenal 5-HT concentration is increased during gastric phase II and phase III. Intravenous infusion of motilin increases luminal 5-HT content and induces gastrointestinal phase III. 5-HT(4) antagonists significantly inhibits both of gastric and intestinal phase III, while 5-HT(3) antagonists inhibited only gastric phase III. These suggest that gastrointestinal MMC cycle is mediated via the interaction between motilin and 5-HT by the positive feedback mechanism. Gastric MMC is regulated via vagus, 5-HT(3/4) receptors and motilin, while intestinal MMC is regulated via intrinsic primary afferent neurons and 5-HT(4) receptors. Stress is highly associated with the pathogenesis of functional dyspepsia. Acoustic stress attenuates gastric phase III without affecting intestinal phase III in conscious dogs, via reduced vagal activity and increased sympathetic activity. It has been shown that subset of functional dyspepsia patients show reduced vagal activity and impaired gastric phase III. The physiological importance of gastric MMC is a mechanical and chemical cleansing of the empty stomach in preparation for the next meal. The impaired gastric MMC may aggravate dyspeptic symptoms following a food ingestion. Thus, maintaining gastric MMC in the interdigestive state is an important factor to prevent the postprandial dyspeptic symptoms.

No MeSH data available.


Related in: MedlinePlus

Effects of acoustic stress on gastrointestinal migrating motor complex (MMC) (A) and heart rate viability (B) in conscious dogs. Acoustic stress almost completely abolishes gastric MMC (body and antrum) without affecting intestinal MMC (duodenum). During acoustic stress loading, heart rate and sympathetic tone (low frequency component; LF) are increased, while parasympathetic tone (high frequency component; HF) is reduced. As a result, the ratio between sympathetic tone and parasympathetic tone (LF/HF) is increaed by acoustic stress. Adapted from Taniguchi et al.83
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Figure 6: Effects of acoustic stress on gastrointestinal migrating motor complex (MMC) (A) and heart rate viability (B) in conscious dogs. Acoustic stress almost completely abolishes gastric MMC (body and antrum) without affecting intestinal MMC (duodenum). During acoustic stress loading, heart rate and sympathetic tone (low frequency component; LF) are increased, while parasympathetic tone (high frequency component; HF) is reduced. As a result, the ratio between sympathetic tone and parasympathetic tone (LF/HF) is increaed by acoustic stress. Adapted from Taniguchi et al.83

Mentions: Acoustic stress forced to hear loud noise through earpieces in conscious dogs. Previous studies demonstrated that acoustic stress delayed the occurrence of the next gastric MMC.80-82 Acoustic stress attenuates gastric phase III without affecting intestinal phase III.83 In order to evaluate the function of autonomic nervous system in a conscious state, heart rate viability analysis has been widely used. During acoustic stress, heart rate and sympathetic tone (low frequency component) are increased, while parasympathetic tone (high frequency component) is reduced (Fig. 6). As gastric phase III, but not intestinal phase III, is regulated by vagal efferent, it is likely that the impaired gastric phase III induced by acoustic stress is mainly due to reduced vagal activity.83 Therefore, if we can improve reduced vagal activity associated stress, impaired gastric phase III would be treatable. It has been shown that somatosensory nerve stimulation restores impaired gastric phase III induced by acoustic stress in conscious dogs.83


Mechanism of interdigestive migrating motor complex.

Takahashi T - J Neurogastroenterol Motil (2012)

Effects of acoustic stress on gastrointestinal migrating motor complex (MMC) (A) and heart rate viability (B) in conscious dogs. Acoustic stress almost completely abolishes gastric MMC (body and antrum) without affecting intestinal MMC (duodenum). During acoustic stress loading, heart rate and sympathetic tone (low frequency component; LF) are increased, while parasympathetic tone (high frequency component; HF) is reduced. As a result, the ratio between sympathetic tone and parasympathetic tone (LF/HF) is increaed by acoustic stress. Adapted from Taniguchi et al.83
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3400812&req=5

Figure 6: Effects of acoustic stress on gastrointestinal migrating motor complex (MMC) (A) and heart rate viability (B) in conscious dogs. Acoustic stress almost completely abolishes gastric MMC (body and antrum) without affecting intestinal MMC (duodenum). During acoustic stress loading, heart rate and sympathetic tone (low frequency component; LF) are increased, while parasympathetic tone (high frequency component; HF) is reduced. As a result, the ratio between sympathetic tone and parasympathetic tone (LF/HF) is increaed by acoustic stress. Adapted from Taniguchi et al.83
Mentions: Acoustic stress forced to hear loud noise through earpieces in conscious dogs. Previous studies demonstrated that acoustic stress delayed the occurrence of the next gastric MMC.80-82 Acoustic stress attenuates gastric phase III without affecting intestinal phase III.83 In order to evaluate the function of autonomic nervous system in a conscious state, heart rate viability analysis has been widely used. During acoustic stress, heart rate and sympathetic tone (low frequency component) are increased, while parasympathetic tone (high frequency component) is reduced (Fig. 6). As gastric phase III, but not intestinal phase III, is regulated by vagal efferent, it is likely that the impaired gastric phase III induced by acoustic stress is mainly due to reduced vagal activity.83 Therefore, if we can improve reduced vagal activity associated stress, impaired gastric phase III would be treatable. It has been shown that somatosensory nerve stimulation restores impaired gastric phase III induced by acoustic stress in conscious dogs.83

Bottom Line: Stress is highly associated with the pathogenesis of functional dyspepsia.It has been shown that subset of functional dyspepsia patients show reduced vagal activity and impaired gastric phase III.Thus, maintaining gastric MMC in the interdigestive state is an important factor to prevent the postprandial dyspeptic symptoms.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, Medical College of Wisconsin and Zablocki VA Medical Center, Milwaukee, Wisconsin, USA.

ABSTRACT
Migrating motor complex (MMC) is well characterized by the appearance of gastrointestinal contractions in the interdigestive state. This review article discussed the mechanism of gastrointestinal MMC. Luminal administration of 5-hydroxytryptamine (5-HT) initiates duodenal phase II followed by gastrointestinal phase III with a concomitant increase of plasma motilin release in conscious dogs. Duodenal 5-HT concentration is increased during gastric phase II and phase III. Intravenous infusion of motilin increases luminal 5-HT content and induces gastrointestinal phase III. 5-HT(4) antagonists significantly inhibits both of gastric and intestinal phase III, while 5-HT(3) antagonists inhibited only gastric phase III. These suggest that gastrointestinal MMC cycle is mediated via the interaction between motilin and 5-HT by the positive feedback mechanism. Gastric MMC is regulated via vagus, 5-HT(3/4) receptors and motilin, while intestinal MMC is regulated via intrinsic primary afferent neurons and 5-HT(4) receptors. Stress is highly associated with the pathogenesis of functional dyspepsia. Acoustic stress attenuates gastric phase III without affecting intestinal phase III in conscious dogs, via reduced vagal activity and increased sympathetic activity. It has been shown that subset of functional dyspepsia patients show reduced vagal activity and impaired gastric phase III. The physiological importance of gastric MMC is a mechanical and chemical cleansing of the empty stomach in preparation for the next meal. The impaired gastric MMC may aggravate dyspeptic symptoms following a food ingestion. Thus, maintaining gastric MMC in the interdigestive state is an important factor to prevent the postprandial dyspeptic symptoms.

No MeSH data available.


Related in: MedlinePlus