Abstract
The purpose of this communication is to outline the results of light microscopic and immunohistological studies of the islets of male CHBB rats actively immunized repeatedly at 2-week intervals for a total of 12 times with homologous islet tissue.
Of 8 animals in the group sensitized with islet antigen and complete Freund's adjuvant, 4 gave a diabetic K-value. In the group sensitized with islet antigen alone, one of 7 animals had a diabetic K-value.
The pancreas of rats actively immunized with homologous islets yielded a wide variety of morphological findings in the islets and islet cells: insulitis, disorderly arrangement and pyknosis of islet cells, total replacement of some islets by a granulomatous lesion composed of infiltrating histiocytic cells, phagocytosis of particles of the nuclei of islet cells, a decrease in B cells (A/B shift) and fibrosis of the islets. On the other hand there was also proliferation and hypertrophy of islets with enlargement of the nuclei and nucleoli of islet cells, and an increase in chromatin and nuclear fission.
