Involvement of DNA fragmentation of enterocytes in mucosal injury to a mouse jejunum incubated in ussing chambers.

A mouse jejunum, when incubated in vitro in Ussing chambers, was found to exhibit morphological deterioration of the villi with denudation of the epithelia (J Nutr Sci Vitaminol, 51: 406, 2005). Our study examined the involvement of apoptosis in an intestinal injury model by a DNA ladder assay and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay. Electrophoresis of mucosal DNA revealed ladders, indicating the occurrence of DNA fragmentation. Cells with TUNEL-positive nuclei were detected among the villus epithelial cells (enterocytes), whereas they are rarely seen among crypt epithelial cells. These features were evident within 1 h after the start of incubation. Apoptotic death of the enterocytes was thus involved in the destruction of villi when incubated in Ussing chambers.