Development of gap junctions between gastric surface mucous cells during cell maturation in rats

The development of gap junctions in rat gastric surface mucous cells during their maturation were examined by indirect immunofluorescence and freeze-fracture methods. Monoclonal antibody against liver gap junction protein stained in large spots along the intercellular junctions between mature gastric surface mucous cells. On the other hand, relatively small fluorescent spots were present over the immature surface mucous cells. The freeze-fracture method showed many large irregular gap junctions between mature surface mucous cells. In immature surface mucous cells, the gap junctions were less developed than those of mature cells, and small gap junctions were occasionally associated with tight junctional strands. Quantitatively, the gap junctions in mature cells were larger and more numerous than those in immature cells. These findings show that gap junctions develop during the maturation of surface mucous cells and suggest that the intercellular communication mediated by gap junctions between gastric surface mucous cells plays an important role in the regulation of cell differentiation and in tissue homeostasis.