Abstract: BACKGROUND ＆ AIM: The morphological and pathological changes of the esophageal and gastric epithelium in mice treated with different concentrations of Lugol's iodine solution were investigated. MATERIALS AND METHODS: 1％, 3％, 5％, 7％, 9％ of Lugol's iodine solutions were perfused into the esophagus of 120 male Kunming mice. Five mice each were killed at 2 hours, 1 day, 3 days and 7 days after Lugol's iodine treatment. The pathological changes of the esophagus and the stomach were examined. RESULTS: Two hours after esophageal perfusion with 7％ and 9％ Lugol's iodine solution, oedema of different degree was found in the lower part of esophageal mucosa of the mice. Three days after perfusion with 3％，5％，7％ and 9％ Lugol's iodine solution, the esophageal epithelia of the mice were covered by a coating. The coating was a mixture of inflammatory cells and squamous epithelium. It became more obvious with the increasing concentration of Lugol's iodine solution. The esophageal epithelium was red and oedematous after the coating was taken away. Seven days after perfusion, the esophageal epithelium recovered in all the five groups. Two hours after esophageal perfusion with 3％，5％，7％ and 9％ Lugol's solution, oedema, ulceration and haemorrhage of different degrees were found in the gastric mucosa. One day later, the inflammation became more serious.Three days after perfusion, the inflammation subsided gradually. The inflammatory reaction of the gastric epithelium in different groups and at different periods were all concentrated on the anterior wall and the greater curvature, with which the Lugol's iodine solution made contact during perfusion. The inflammation in the fore stomach which was covered with squamous epithelium was obviously less severe than that of gastric mucosa with columnar epithelium. The pathological changes of the esophagus and fore stomach consisted of exfoliation of the squamous epithelium and infiltration of inflammatory cells. The changes of the gastric mucosa showed necrosis, haemorrhage, and infiltration of inflammatory cells on the anterior wall. CONCLUSION: Lugol's iodine solution perfused into the esophagus could damage the mucosa of the esophagus and stomach even at very low concentration. The damage became worse with increase of the concentration.

Key words: Lugol's solution, esophagus, gastric mucosa injury