Changes of A, B and D cells in Langerhans islets in pancreatic cancers of hamsters.

In order to clarify the effect of pancreatic hormones on the oncogenesis of pancreatic cancer, the kinetics of the B, A and D cells in the islets of Langerhans were studied in hamsters with pancreatic cancer induced by di-iso-propanol nitrosamine (DIPN). Tumors appeared histologically 8 weeks and duct adenocarcinomas became evident 12 weeks after the administration of DIPN. Although the area of the islets did not change in 8 to 16 weeks, the numbers of B cells was decreased 8 weeks after the administration of DIPN and of A and D cells was decreased at 16 weeks. The area occupied by B cells in proportion to the number of islet cells showed a significant decrease 8 weeks after the administration of DIPN. Since insulin has been reported to have a trophic effect on the exocrine pancreas, our findings suggest that pancreatic B cells start to decrease at the same time that pancreatic cancer begins to form. Thus, insulin appears to play an important role locally in the oncogenesis of pancreatic cancer in acinar cells.