Avaliação do papel da serotonina e seus receptores no desenvolvimento da constipação intestinal

Abstract

Chagas´ disease affects 8-10 million people in the Americ. In the chronic phase of this disease, patients can develop alterations in the gastrointestinal tract, and one of them is called megacolon. It is accepted that the disturbance of immune system and enteric nervous system (ENS) is associated with this form development. Some substances act in both systems and fulfill a link between the nervous and immune systems. One of these substances is the serotonin (5-HT) that composes the group of biogenic amines (neurotransmitters). About 90% of serotonin existent in the human body is produced in the intestine. Previous data indicated that the intestinal levels of serotonin may provide a balance between ENS and immune system. To evaluate whether serotonin intestinal levels are related with regulation of immune system, we investigated the relation among 5-HT expression, intensity of inflammatory process and denervation in colon samples from patients with megacolon. We evaluated, by immunohistochemistry technique, samples of colon from patients submitted to necropsy or surgical procedures at Federal University of Goias (Goiânia, Minas Gerais, Brazil). This work was approved by UFU Research Ethics Committee (ETIC n° 110/11). It was used antibodies linked with immunofluorescent markers to measure the presence of serotonin, CD8 lymphocytes and peripherin (neuronal marker). Our results indicated that low levels of serotonin are associated with intense inflammatory process, high degree of inflammation and with constipation intestinal. These data suggested that serotonin may act in the intestine as a regulator of inflammation process and avoid the neuronal destruction.