# Levels of 5-Hydroxytryptamine Increase After Meals in women with IBS



## eric (Jul 8, 1999)

FYILevels of 5-Hydroxytryptamine Increase After Meals in Women With Irritable Bowel SyndromeNEW YORK Reuters Health May 05 - Platelet-depleted plasma 5-hydroxytryptamine 5-HT levels increase after meals in women with diarrhea-predominant irritable bowel syndrome d-IBS whose symptoms increase following food ingestion, according to a report in the May issue of Gut.In small studies, 5-HT concentrations in platelet-poor plasma appear higher in women with d-IBS than in healthy women, the authors explain, suggesting a possible link between 5-HT and postprandial symptom exacerbations or IBS itself.Dr. L. A. Houghton from University Hospital of South Manchester, UK and colleagues assessed 5-HT and 5-HIAA its metabolite concentrations, 5-HT turnover, and platelet 5-HT stores in 39 women with d-IBS and 20 healthy female volunteers before and after a standard carbohydrate meal.Although there was no difference in the ratio of postprandial to fasting 5-HT levels between d-IBS patients and healthy controls, the authors report, d-IBS subjects did have higher postprandial concentrations of 5-HT with earlier peak 5-HT levels than did healthy women.Women with d-IBS who reported symptoms following the meal also tended to have higher 5-HT concentrations and higher peak concentrations than did other women, the report indicates, though there was no difference in the time to peak levels compared with asymptomatic women with d-IBS.Fasting 5-HIAA levels were higher in d-IBS women than in healthy controls, the researchers note, but postprandial concentrations did not differ.Fasting and postprandial 5-HT turnover the ratio of 5-HIAA to 5-HT levels did not differ between healthy controls and women with d-IBS, the results indicate, but d-IBS subjects with postprandial symptoms tended to have a lower 5-HT turnover than did d-IBS women without symptoms.Women with d-IBS had significantly higher platelet 5-HT stores than did healthy women, the investigators find, though levels did not differ between d-IBS patients with and without postprandial symptoms."Our results have shown for the first time that symptom exacerbation following meal ingestion in female subjects with d-IBS is associated with increased levels of plasma 5-HT, together with a reduction in 5-HT turnover," the authors conclude. "In addition, baseline platelet stores of 5-HT are elevated in female subjects with d-IBS compared with healthy subjects, supporting increased exposure of platelets to 5-HT in the systemic circulation.""Platelet 5-HT concentrations may have a potential role to play as a marker in the diagnosis and management of d-IBS," the researchers suggest. "This would be similar to the way glycosylated hemoglobin is used to reflect mean blood glucose concentration over a prolonged time period in patients with diabetes mellitus."The investigators add, "Further studies addressing both mucosal 5-HT concentrations and enteroendocrine cell numbers in subjects with d-IBS, as well as similar studies to the present one conducted in subjects with constipation predominant IBS and assessing the transient relationship between symptoms and the 5-HT system need to be performed."Gut 2003;52:663-670. http://www.medscape.com/viewarticle/453489


----------

