CAUTIONARY NOTE ON THE USE OF END-LABELING DNA FRAGMENTS FOR DETECTION OF APOPTOSIS

The gastrointestinal eipthelum undergoes a continual process of cell r enewal which is partly regulated by apoptosis. The process of growth a nd differentiation is greatly enhanced in the terminal ileum after mas sive small bowel resection, a well-established model of intestinal ada ptation. We have applied the terminal deoxynucleotidyl transferase (Td T)-mediated UTP nick end-labelling (TUNEL) method to establish the rol e of apoptosis in intestinal adaption in terminal ileum of control ani mals after small bowel resection. Healing skin wound and lymph node we re used as positive control tissue for apoptotic cells. We report that considerable inter-animal variation was observed in the intestinal ti ssue. We believe that caution is required in the interpretation of TUN EL staining in intestinal tissue and in its use as a specific marker f or apoptosis in this setting.