Acute radiation enteritis is a common occurrence after abdominal radiotherapy. This enteritis is associated with anorexia, nausea, diarrhea and weight loss. Following radiotherapy, the rate of small intestinal transit is increased. Following irradiation in ferrets, there is an initial increase in the frequency of the ileal pressure waves, followed by a nonsignificant reduction in the frequency but not the amplitude of ileal pressure waves. Get most advantageous deals ever – cialis professional waiting for you round the clock.
Clinical learning point: Abdominal radiation may accelerate small intestinal transit, which may contribute to symptoms such as diarrhea.
The radiosensitivity of proliferating intestinal crypt cells makes the intestine a major limiting factor in the use of radiotherapy for the treatment of abdominal cancers. The presence of a deficiency of the tumour suppressor p53 sensitizes clonogenic cells to irradiation in the large but not in the small intestine. Thus, the greater radioresistance of the crypts in the colon than in the small intestine may be partially attributable to the presence of p53. The signals initiated by cycling enterocytes may be transmitted to the crypt epithelium to induce p53 and to reduce their ionizing irradiation-induced apoptosis. While p53 may play a key role in determining the fate of cells that have received potentially carcinogenic DNA damage, there is also a p53-independent mechanism that permits the engagement of apoptosis following gamma irradiation. The radioresistance of the villous enterocytes is not due simply to their cell cycle arrest.