Humoral-mediated cytotoxicity to rat pancreatic exocrine cells in serum of diabetes-prone BB/OK rats--predictive value for diabetes onset.

Diabetes-prone BB/OK rats were checked in a follow-up study between 40 and 200 days of age for the appearance of humoral-mediated cytotoxicity to rat pancreatic exocrine cells in serum by 51Cr-release assay. BB/OK rats maintaining normoglycaemia were characterized by a pronounced decrease of anti-exocrine cell cytotoxicity in serum at 75 and 105 days of age compared to the initial value at day 40. In contrast, in animals developing diabetes cytotoxicity was found more frequently and the level of cytotoxicity did not likewise decrease during the period up to diabetes onset. With respect to the prediction of diabetes in individual BB/OK rats the retrospective analysis revealed that 81.0% of those animals displaying cytotoxicity at 75 days of age subsequently developed diabetes. If sera from BB/OK rats were identified as non-cytotoxic at day 75 and also at 105 days of age normoglycaemia persisted in 83.3% of these animals. Thus, screening of young diabetes-prone BB/OK rats for the presence of humoral-mediated cytotoxicity to pancreatic exocrine cells in serum seems to facilitate the identification of potential diabetic or long-term normoglycaemic animals in the BB/OK rat population.