Apoptotic process in the monkey small intestinal epithelium: I. Association with glutathione level and its efflux

The apoptotic process in the normal gastrointestinal mucosa is of interest due to its possible role in physiological cell renewal. The aim of this stu dy was to identify the apoptotic process in the monkey small intestine and the association of glutathione level and its efflux in this process. Monkey small intestinal epithelial cells were separated in to different fractions consisting of villus, middle and crypt cells. Apoptosis was identified by DNA ladder pattern and Hoechst staining. The level of glutathione, its effl ux and the enzymes involved in its metabolism were quantitated in these fra ctions. Apoptotic cells were identified predominantly in the villus tip cel l fractions by both DNA ladder pattern and Hoechst dye staining. Glutathion e level was 7 fold higher in the crypt cells as compared to villus tip cell s the middle cells showing a gradual decrease. A similar pattern was seen i n mitochondrial content of glutathione. As the cells mature from crypt to v illus, there is increased efflux of GSH, which may be responsible for the d ecreased level of GSH in apoptotic villus cells. In the monkey small intest ine, apoptotic cells are seen in the villus tip fractions and the glutathio ne level and its efflux may play a role in this process. (C) 1998 Elsevier Science Inc.