Immunohistochemical and ultrastructural study on the islet of autotransplanted pancreas in dogs

: This study was conducted to clarify the quantitative and qualitative changes of the islet cells of Langerhans in the autotransplanted pancreas. The left lobe of the canine pancreas was autotransplanted to the left iliac fossa with pancreatic duct left open to the peritoneal cavity. Fibrosis of transplanted pancreas progressed after transplantation. B-cell ratio was decreased significantly (p less than 0.01) whereas A-cell ratio and D-cell ratio showed no significant changes. Ultrastructural study revealed the increase of collagen/bundle, degranulation of B-cells and well preservation of A-cell granules at 3 weeks after operation. B-cells with dark cytoplasm were found at 7 weeks after operation which indicate the dysfunction of B-cells. In contrast, clusters of immature B-cells appeared on some sections obtained from the pancreas 14 weeks after autotransplantation. On the other hand, K-values were decreased significantly 7 weeks after operation (p less than 0.05). sigma BS (integrated response value of serum glucose level during IVGTT) was increased significantly (p less than 0.01) in addition to the decrease of K-values (p less than 0.01) at 11 weeks after operation. It proved that any indices at 14 weeks after operation showed no significant changes from the control group. It might be possible to speculate that relatively well preservation of glucose tolerance at 14 weeks after operation is associated with some clusters of immature B-cells observed ultrastructurally.