APOPTOSIS IN THE SMALL-INTESTINAL ALLOGRAFT OF THE RAT

Background Necrosis and apoptosis are different cell death mechanisms. Necrosis is a pathological process that occurs after destruction of t he cell membrane. Apoptosis is a DNA-dependent cell death mechanism, w hich occurs under physiological and pathological conditions. Although necrosis is a well-defined phenomenon in an acute graft rejection, the occurrence and relevance of apoptosis during this process is largely unknown. Methods. The enterocyte apoptosis rates in allografted (n=24) and isografted (n=24) small intestines of the rat were compared using the in situ end-labeling technique. Results. In situ end-labeling sho wed a dramatically increased number of apoptotic enterocytes in allogr afted small intestines, whereas increased labeling could not be observ ed in isogeneic small intestinal grafts. Conclusions. We suggest that graft rejection-associated apoptosis, in addition to necrosis, plays a n important role in the course of organ failure, and that the degree o f apoptosis represents another reliable indicator for the diagnosis an d prognosis of transplant rejection.