[Changes of glycogen or sacchariferous materials in esophageal epithelium tissue]

It was known that mucosal iodine staining could be used to improve the endoscopic visualization of esophageal premalignant lesion and cancer. However, the method was not used widely because of lacking clear mechanism. This study was designed to investigate the mechanism of esophageal epithelium staining with iodine and changes of glycogen or sacchariferous materials.

Esophageal epithelium was stained with iodine in endoscopic examination. According to color of tissue, the esophageal carcinoma and premalignant lesion were diagnosed. Glycogen from the esophageal mucous epithelium was extracted with beta-glycerophosphate buffer. The content of glycogen in the tissue speciman was detected by periodic acid-shiff staining (PAS). Protein in the esophageal mucous epithelium was extracted by tissue homogenate method.

After iodine staining, the normal epithelium became brown and easier to distinguish normal epithelium from precancerous of premalignant epithelium according to the change of color. Furthermore, normal epithelium slice stained by PAS technique had red reaction but it had no reaction after pretreatment by amylase. However, precancerous and premalignant epithelium tissue slices could not be stained whenever they were pretreated by amylase. The content of glycogen extracted from the esophageal epithelium was lower significantly than those of normal tissue (P < 0.01). But it was no deviation that protein contents of normal esophageal epithelium were compared with carcinoma tissue (P > 0.05).

These results demonstrated that glycogen and sacchariferous materials in esophageal carcinoma and premalignant lesion tissue decreased significantly and result in light yellow area by iodine staining. It may be helpful for diagnosis of esophageal carcinoma.