The determination of the melatonin receptors expression (MT-1, MT-2) in a stomach and duodenal mucous membrane as a way to predict the pylorobulbar ulcers activity

Abstract

Introduction: In spite of all prognoses by the late 1980 s the revision of the medicamental treatment principles didn’t lead to expecting complication rate decreasing. Furthermore, over the last 10 years the number of patients with stomach and duodenal ulcers, which enter the hospitals in Russia because of ulcer perforation, increased in 2,7 times and the number of ulcer bleeding patients - in 2,2 times. All this evidences point out the necessity to determine new factors of the ulcer pathogenesis and to hnd new mechanisms of the ulcer formation. Subject to melatonin properties at the level of the whole body (biorhythm, antioxidant, immunomodulatory effect) and also at the level of the digestive system (participation of the motor activity, microcirculation and proliferation); it’s easy to see, that a melatonin plays a great part in pathogenic mechanisms of the ulcer formation and exacerbation. Recently the papers, pointing to receptor-mediated mechanism of the melatonin anti-inflammatory effect, appeared. Aim: This study’s aim is to determine connection between receptor expression to melatonin (MT-1, MT-2) and probable ulcer complication prognosis. Materials and methods: Our research consists of two parts. In experimental one we got primary specific antibodies to MT-1, MT-2. The peptide, duplicating amino-acid sequence of active MT-1, MT-2 receptor centers, was synthesized in Research institute of particularlycleanbiological preparation. In clinical part we exposed stomach and duodenal mucous membrane cells with MT-1, MT-2 receptors by indirect immunofluorescence. 35 patients were researched, they divided into few groups: uncomplicated ulcer - 16 patients, ulcer with perforation - 6, ulcer with bleeding - 5, control group - 8. Results: In uncomplicated ulcer group there were 7% MT-1 and 6,5% MT-2 melatonin receptors, in ulcer perforation group: 9,56% MT-1 and 2,53% MT-2; in ulcerbleeding group - 10,56% MT-1 and 1,46% MT-2; incontrol group - 16% MT-1 and 14,7% MT-2. After carefully examination of the groups with complications it was founded, that 85% patient has a similar melatonin receptor distribution (the receptor number decreased and decreasing MT-2 relative to MT-1 - 4 times). It was exposed 4 patients in group without complications, which can be in a complication group according to results. We can suppose that they are in a risk group of the ulcer complications and they need more careful control and perspective researching. Conclusions: • Patients with any ulcer defect have depressed level of the melatonin receptors. • There is decrease of MT-2 receptors relative to MT-1 in 4 times in group of patients with ulcer complication. It can be used in complication prediction. • Probably, the duration of ulcer case history influences the melatonin receptor expression, but we need additional study and general sampling to prove this.