Alteration of Pancreatic Endocrine Cell Patterns and Their Secretion during Pancreatic Carcinogenesis in the Hamster Model1

Proliferation of endocrine cells was found to occur during early, i.e., first 12 weeks, exocrine pancreatic carcinogenesis after 6 weekly treat ments of Syrian hamsters with the pancreatic carcinogen A'-nitrosobis(2oxopropyl)amine (BOP). Cells containing insulin (Ins), glucagon (Glu), and somatostatin (Som) were noted in all stages of tumor development and were present in adenocarcinomas and in métastasesto the liver. Some of the cancer cells were of ¡impiumilo(hybrid) type, i.e., produced both murili and endocrine substances. Measurement of these hormones revealed a significant decrease in plasma Ins during early stages of carcinogenesis with concomitant increase of Ins level in pancreatic juice at 12 weeks after 6 weekly BOP treatments. Plasma Glu and Som were not changed. The changes noted, particularly in relation to Ins, suggest that proliferation of endocrine cells in pancreatic carcinogenesis may be associated with alterations in hormone secretion.