Interaction of leptin with gastric myofibroblast transdifferentiation in Helicobacter pylori‐infected Mongolian gerbils: the effect of rebamipide

Summary Background : Our recent histochemical studies have revealed the marked increase of myofibroblasts in the Helicobacter pylori‐infected Mongolian gerbil fundic mucosa, while the mediators, which facilitate the conversion of fibroblasts to the myofibroblasts have remained unknown. Aim : The present study was undertaken to clarify the alteration of leptin in the control and H. pylori‐infected Mongolian gerbil stomach. The effector sites of rebamipide were also investigated in relation to leptin. Methods : The localization of leptin was investigated by the indirect immunofluorescence. Plasma leptin levels were determined by ELISA method. The localization of 3H‐rebamipide binding sites was investigated by autoradiography. Results : Serum leptin content in H. pylori‐infected Mongolian gerbils was significantly increased. The presence of leptin immunoreactivity was recognized in the endothelial cells of the microcirculatory network and very weakly in the glandular cells in the control group, while in the H. pylori‐infected group leptin was markedly recognized in the mesenchymal cells. Rebamipide bound to the fibroblasts and surface mucous cells and decreased the leptin immunoreactivity in the gastric mucosa. Conclusions : Leptin was mostly found in the mesenchymal cells. Rebamipide administration brought about the decrease of leptin in the gastric mucosaof the H. pylori‐infected gerbils.