OBJECTIVETo explore the significance of the expression of carcinoembryonic antigen receptors (CEAR) in digestive organs.

METHODSSpecimens were procured from 20 male BALB/c mice including esophagus, small intestine, stomach, colon, pancreas, and liver. Kupffer cells were obtained by density gradient centrifugation following enzymatic digestion of the fresh liver specimen. Immunohistochemistry and immunocytochemistry methods were used to detect CEAR in those organs or Kupffer cells.

RESULTSCEAR was found both in cytoplasm and nuclei of the digestive tract mucosal epithelial cells and pancreas islet cells, but only in the cytoplasm of liver cells, Kupffer cells, and smooth muscle cells of the whole digestive tract. The mean ranks of CEAR expression were 174.33 in the mucosal epithelial cells of colon, 160.70 in epithelial cells of small intestine, 139.18 in Kupffer cells, 137.43 in pancreas islet cells, 131.70 in liver cells, 124.23 in gastric epithelial cells, 77.15 in esophageal epithelial cells and 57.80-71.00 in smooth muscle cells of the entire digestive tract examined. There were significantly differences in the CEAR expression intensity among those positive cells (chi2=99.58, P<0.01) while CEAR was not present in submucosal connective tissue cells, pancreatic exocrine cells, or hepatic sinusoid endothelial cells.

CONCLUSIONThere are significantly differences in the expression of CEAR in the main digestive organs according to the different tissue and cells, which may play an important role in the carcinogenesis and hepatic metastasis from tumors of the digestive system.