Influence of pancreatic secretion on late radiation enteropathy in the rat.

In female Wistar rats a 10 cm long exteriorized mid small intestinal segment was roentgen irradiated 3 weeks after a pancreatic duct-occluding operation/sham operation. Roentgen doses were 19 and 21 Gy as single exposures. Radiation injury was assessed 2, 8 and 26 weeks after irradiation using one macroscopic and 7 histopathologic parameters. The parameters were graded according to severity, and a radiation injury score was calculated by adding the scores for the individual parameters. Two and 8 weeks following irradiation there was no difference between pancreatic duct-occluded and sham operated animals. Twenty-six weeks after irradiation all parameters of radiation injury except the extent of vascular sclerosis were less marked in pancreatic duct-occluded rats than in controls. It is concluded that exocrine pancreatic secretions may influence the development of late changes following irradiation, and that these changes seem to be mainly independent of the degree of vascular sclerosis.