Migrating Motor Complex in Colectomized Ileo Stoma Patients

Clinical Utility of Ileal Motility in Children With Defecation Disorders and Children With Chronic Intestinal Pseudo-Obstruction

BACKGROUND

Little is known about ileal motility patterns and their utility in children. Here, we present our experience with children undergoing ileal manometry (IM).

METHODS

A retrospective review of children with ileostomy comparing IM between 2 groups: A [chronic intestinal pseudo-obstruction (CIPO)] and B (feasibility of ileostomy closure in children with defecation disorders). We also compared the IM findings with those from antroduodenal manometry (ADM), and evaluated the joint effect of age, sex, and study indication group on IM results.

RESULTS

A total of 27 children (median age 5.8 years old, range 0.5-16.74 years, 16 were female) were included (12 in group A and 15 in group B). There was no association between IM interpretation and sex; however younger age was associated with abnormal IM ( P = 0.021). We found a significantly higher proportion of patients with presence of phase III of the migrating motor complex (MMC) during fasting and normal postprandial response in group B than in group A ( P < 0.001). Logistic regression analysis revealed that only Group B was associated with normal IM ( P < 0.001). We found a moderate agreement for the presence of phase III MMC and postprandial response between IM and ADM (kappa = 0.698, P = 0.008 and kappa = 0.683, P = 0.009, respectively).

CONCLUSION

IM is abnormal in patients with CIPO and normal in patients with defecation disorders, suggesting that IM may be not needed for ostomy closure in those with defecation disorders. IM has a moderate agreement with ADM and could be used as a surrogate for small bowel motility.

Nitric oxide regulation of migrating motor complex: randomized trial of N(G)-monomethyl-L-arginine effects in relation to muscarinic and serotonergic receptor blockade

AIM

The migrating motor complex (MMC) propels contents through the gastrointestinal tract during fasting. Nitric oxide (NO) is an inhibitory neurotransmitter in the gastrointestinal tract. Little is known about how NO regulates the MMC. In this study, the aim was to examine nitrergic inhibition of the MMC in man using N(G)-monomethyl-L-arginine (L-NMMA) in combination with muscarinic receptor antagonist atropine and 5-HT3 receptor antagonist ondansetron.

METHODS

Twenty-six healthy volunteers underwent antroduodenojejunal manometry for 8 h with saline or NO synthase (NOS) inhibitor L-NMMA randomly injected I.V. at 4 h with or without atropine or ondansetron. Plasma ghrelin, motilin and somatostatin were measured by ELISA. Intestinal muscle strip contractions were investigated for NO-dependent mechanisms using L-NMMA and tetrodotoxin. NOS expression was localized by immunohistochemistry.

RESULTS

L-NMMA elicited premature duodenojejunal phase III in all subjects but one, irrespective of atropine or ondansetron. L-NMMA shortened MMC cycle length, suppressed phase I and shifted motility towards phase II. Pre-treatment with atropine extended phase II, while ondansetron had no effect. L-NMMA did not change circulating ghrelin, motilin or somatostatin. Intestinal contractions were stimulated by L-NMMA, insensitive to tetrodotoxin. NOS immunoreactivity was detected in the myenteric plexus but not in smooth muscle cells.

CONCLUSION

Nitric oxide suppresses phase III of MMC independent of muscarinic and 5-HT3 receptors as shown by nitrergic blockade, and acts through a neurocrine disinhibition step resulting in stimulated phase III of MMC independent of cholinergic or 5-HT3 -ergic mechanisms. Furthermore, phase II of MMC is governed by inhibitory nitrergic and excitatory cholinergic, but not 5-HT3 -ergic mechanisms.

Serotonin: from top to bottom

Serotonin is a monoamine neurotransmitter, which is phylogenetically conserved in a wide range of species from nematodes to humans. In mammals, age-related changes in serotonin systems are known risk factors of age-related diseases, such as diabetes, faecal incontinence and cardiovascular diseases. A decline in serotonin function with aging would be consistent with observations of age-related changes in behaviours, such as sleep, sexual behaviour and mood all of which are linked to serotonergic function. Despite this little is known about serotonin in relation to aging. This review aims to give a comprehensive analysis of the distribution, function and interactions of serotonin in the brain; gastrointestinal tract; skeletal; vascular and immune systems. It also aims to demonstrate how the function of serotonin is linked to aging and disease pathology in these systems. The regulation of serotonin via microRNAs is also discussed, as are possible applications of serotonergic drugs in aging research and age-related diseases. Furthermore, this review demonstrates that serotonin is potentially involved in whole organism aging through its links with multiple organs, the immune system and microRNA regulation. Methods to investigate these links are discussed.