[The digestive barrier functions of the enzymatic systems of the normal small intestine and in pathology].

The fact that the enzymes splitting food nutrients, those of protein nature in particular, not only in the epithelial cells of the small bowel, but in the lower structures of the intestinal wall, i.e. in the stromal and muscle serous layers, is shown for the first time. They are integral parts of the intestinal enzymatic barrier that protects the internal medium of the body from penetration of proteins and peptides. The activities of the enzymes which are present in the epithelial, stromal, and muscle serous layers have been demonstrated to be substantially changed in disorders (immobilization in the presence of starvation, surgical interventions into the small bowel). It is suggested that examining the functions of the postepithelial enzymatic barrier along with those of the epithelial and immunological ones will provide a deeper insight into some certain disorders of the alimentary tract.