The occurrence of electron dense intercellular materials and gap junctions in the human intestinal epithelium

Electron microscopy of biopsy specimens from the small intestines in infants and children with various gastrointestinal disturbances revealed that the intercellular space of the mucosal epithelium was often filled with electron dense materials. Here apposed cell membranes were arranged almost parallel with each other. The dense materials also filled the space just subjacent to the epithelium to form a thick, dense layer in which the basal lamina was completely buried. The gap junctions were especially well developed in the epithelia filled with these materials. Long-period fasting of patients seemed to facilitate the occurrence of the dense materials and the formation of gap junctions.