Morphological studies in dogs with chronic pancreatic insufficiency.

The pancreas of dogs with the clinical syndrome of chronic pancreatic insufficiency was examined macroscopically, by light- and electron microscopy and immunohistochemically. The pancreatic tissue was reduced in volume, the lobular architecture was disturbed and the ductal system prominent. Many acini were shrunken and contained cells with pyknotic nuclei. The islets of Langerhans were highly irregular, often difficult to identify. Many B cells occurred isolated within the exocrine tissue. Ultrastructurally, changes in the acinar cells included alterations in the chromatin pattern and dilatation of the cisternae of the rough endoplasmic reticulum. In endocrine cells nuclear deformations, chromatin condensation and progressive loss of secretory granules were seen, accompanied by vacuolization of the cytoplasm. The changes included all endocrine cell types. This complex of pancreatic lesions is considered to be of degenerative origin. The aetiology of the disease is unknown.