Methylglyoxal Induces Systemic Symptoms of Irritable Bowel Syndrome

<div><p>Patients with irritable bowel syndrome (IBS) show a wide range of symptoms including diarrhea, abdominal pain, changes in bowel habits, nausea, vomiting, headache, anxiety, depression and cognitive impairment. Methylglyoxal has been proved to be a potential toxic metabolite produced by intestinal bacteria. The present study was aimed at investigating the correlation between methylglyoxal and irritable bowel syndrome. Rats were treated with an enema infusion of methylglyoxal. Fecal water content, visceral sensitivity, behavioral tests and serum 5-hydroxytryptamine (5-HT) were assessed after methylglyoxal exposure. Our data showed that fecal water content was significantly higher than controls after methylglyoxal exposure except that of 30 mM group. Threshold volumes on balloon distension decreased in the treatment groups. All exposed rats showed obvious head scratching and grooming behavior and a decrease in sucrose preference. The serum 5-HT values were increased in 30, 60, 90 mM groups and decreased in 150 mM group. Our findings suggested that methylglyoxal could induce diarrhea, visceral hypersensitivity, headache as well as depression-like behaviors in rats, and might be the key role in triggering systemic symptoms of IBS.</p></div

Effects of methylglyoxal on sucrose preference test.

<p>The SPT scores of the 150 mM group were decreased. *<i>p</i><0.05 versus controls.</p

Effects of methylglyoxal on head scratching and grooming behaviors.

<p>The time of scratching behavior in all treatment groups markedly increased compared with controls. **<i>p</i><0.01 versus controls.</p

Effects of methylglyoxal on serum 5-HT level.

<p>The serum 5-HT levels of 30 mM, 60 mM and 90 mM groups were markedly higher than controls. The difference between 120 mM group and controls was not significantly. The level of 5-HT in 150 mM group rats was decreased than controls. **<i>p</i><0.01 versus controls, *<i>p</i><0.05 versus controls.</p