The effect of duct obliteration on the histology and endocrine function of the canine pancreas.

Although duct obliteration is a safe and effective method for ablation of exocrine secretion in segmental pancreas transplantation, it remains to be clarified whether its effects are restricted to the exocrine tissue. In 20 dogs (beagles 9-15 kg) the right lobe of the pancreas was removed and the ductal system of the left lobe was injected with the duct-obliterants neoprene (6 dogs), polyisoprene (6 dogs), or prolamine (8 dogs). In this study, i.v. glucose tolerance tests (the results of which are expressed in K values) and relaparotomies for taking biopsies were performed at 1, 3, and 12 months after duct obliteration. Biopsies were studied histologically and immunohistochemically in a qualitative and semiquantitative fashion. Three prolamine-injected dogs developed diabetes. All other dogs maintained normal fasting blood glucose levels but showed reduced K values at 1 month after duct obliteration. Further deterioration of glucose tolerance was not observed up to 12 months. Differences in K values depending on the type of obliterant were insignificant at all intervals. The exocrine tissue was completely replaced by fibrosis at 3 months after duct obliteration, and the architecture of the islets was disrupted. Morphometrical analysis of relative numbers of different endocrine cell types showed transient changes at 1 month after duct obliteration, but did not differ from unmodified controls at 12 months. We conclude that the effects of duct obliteration are not restricted to the exocrine pancreatic tissue, but that the endocrine pancreas is interfered with as well. Changes in islet function and histology are brought about during the first month after duct obliteration and stabilize thereafter.