RESUMO
UNLABELLED: Melatonin possesses enteroprotective proprieties. An action of a gastrointestinal motility modulator is also attributed to this hormone. Clinical investigations have proven that melatonin plays a role mainly in the pathogenesis of upper gastrointestinal tract disorders, much less data have been published on its action in intestinal disorders. AIM OF THIS STUDY: To evaluate melatonin (MEL) secretion and its metabolism to 6-hydroxymelatonin sulfate (6HMS) in patients with irritable bowel syndrome (IBS). MATERIAL AND METHODS: 75 subjects, aged 18-52 years were included in this study. Three groups were distinguished: K (n=25)--healthy volunteers, IBS-D (n=25)--patients with diarrhoea predominant IBS, IBS-C (n=25)--subjects with constipation predominant IBS (IBS-C). IBS was diagnosed according to Rome III Criteria. Blood samples were taken from cubital vein at 2:00 a.m. and 8:00 a.m. on the next day. Concentrations of MEL in serum and 6HMS in 24-hour urine collection were determined by immunoenzyme ELISA method employing standard kits IBL nr RE59121 i RE59131). RESULTS: The average melatonin concentration at 2:00 a.m. was found to be in the studied groups: K-55.3 +/- 6,6 pg/ml, IBS-D--57.5 +/- 16.7 pg/ml (p > 0.05), IBS-C--75.5 +/- .3 pg/ml (p < 0.01) and at 8:00 a.m. adequately--7.3 +/- 4.0 pg/ml, 14.9 +/- 8.9 pg/ml (p < 0.001) and 15.1 +/- 7.2 pg/ml (p < 0.001). 24-hour urinary 6HMS excretion amounted to: K--15.10 +/- 6.37 microg/ 24h, IBS-D--27.67 +/- 26.71 microg/24h (p < 0.05), IBS-C--31.47 +/- 29.19 microg/24h (p < 0.01). CONCLUSION: Melatonin secretion in patients with IBS, especially in patients with IBS-C, is significantly increased compared with healthy volunteers. Melatonin metabolism in patients with IBS is not disturbed.
