1993 Volume 24 Issue 2 Pages 205-212
The mechanism of the development of serotonin-induced gastric mucosal lesions was experimentally studied by administration of exogenous serotonin in rats. The factors considered to affect the microcirculation, such as gastric mucosal blood flow and platelet aggregation, were investigated. Biogenic amines (histamine, serotonin) were also investigated as regulating factors of gastric mucosal blood flow. Furthermore distribution of serotonin in the gastric mucosa was investigated immunohistochemically. Serotonin-induced gastric mucosal lesions were histopathologically observed as hemorrhagic erosion with congestion and necrosis. Gastric mucosal blood flow was significantly decreased soon after the administration of serotonin. Platelet aggregation was also accelerated. As to the distribution of serotonin in the gastric mucosa, cells with positive immunoreaction were found in the deep layer adjacent to the submucosa as well as in the submucosa. These cells were supposed to be mast cells or enterochromaffin cells. The incidence of gastric mucosal lesions closely corresponded with the decrease of mucosal blood flow. These circulatory disturbances seemed to play an important role on the development of the gastric mucosal lesions after administration of serotonin.
