[The influence of melatonin on concentration of nitric oxide metabolites in gastric juice in subjects with functional dyspepsia].

UNLABELLED: The pathogenesis of functional dyspepsia is very complicated and its etiology is still not clear. One of the supposed pathophysiological mechanisms is the deficiency of melatonin. The deficiency of melatonin leads to increase the oxide reactive form's concentration as nitric oxide metabolites and to decrease of antyoxidative enzymes activity. This last factor seems to be very important in correct digestive tract function. The aim of our study was answer the question if is the difference between NO metabolites concentraction in gastric juice in patients with functional dyspepsia and in healthy subjects and wheather the treatment with melatonin plays the role in normal digestive tract function.

MATERIAL AND METHODS: The study included 60 subjects between of 18 to 48 years with diagnosed functional dyspepsia (according to the Rome III Criteria). The study group was divided into two subgroups: group I--30 subjects with Epigastric Pain Syndrome-EPS and group II--30 subjects with Postprandial Disorders Syndrome-PDS. Control group comprised 25 healthy subjects (without any clinical or morphological symptoms of digestive tract disease). In each patient the gastroscopy was performed. During gastroscopy 5 ml gastric juice was collected. The juice was centrifuged for 15 min (4500 rotations). The undiluted supernatant was frozen in the temperature -70 degrees C. The concentration of nitric oxide metabolites in gastric juice was determined with spectrophotometric based on ELISA test (540 nm wavelength) using a microplates reader (Multiscan, Labsystems). In patients with functional dyspepsja the investigations were performer twice before and after 6 weeks treatment with melatonin. Melatonin was applied in dose 5 mg daily, in the evening.

RESULTS: The concentration of nitric oxide metabolites in gastric juice in healthy subjects was 6.81 +/- 2.23 microM. In patients with functional dyspepsia was significantly higher; in patients with Epigastric Pain Syndrome--10.99 +/- 2.46 microM (p < 0.05), in patients with Postprandial Disorders Syndrome--9.28 +/- 2.18 microM (p < 0.05). After treatment with melatonin the concentration of nitric oxide metabolites in gastric juice in both groups decreased and were 8.21 +/- 1.83 microM in patients with Epigastric Pain Syndrome and 6.93 +/- 1.61 microM in patients with Postprandial Disorders Syndrome.

CONCLUSIONS: In patients with functional dyspepsia the concentration of nitric oxide metabolites in gastric juice was significantly higher than in control group. After treatment with melatonin the concentration of nitric oxide metabolites in gastric juice in both groups decreased--in patients with Epigastric Pain Syndrome as well as in patients with Postprandial Disorders Syndrome. The treatment with melatonin seems to be suitable in combined therapy of functional dyspepsia.