The activation of 3H-labeled N-nitrosobis(2-oxopropyl)amine by isolated hamster pancreas cells

Abstract
The activation of 3H-labeled N-nitrosobis(2-oxopropyl)amine ([3H]BOP) by pancreas acinar and duct tissue from Syrian hamsters and MRC-Wistar rats in vitro was measured as DNA alkylation. Hamster tissue was incubated with [3H]BOP (0.1 mM; 20 μCi/ml) for 2 h. Initial levels of alkylation were similar, 41.7±3.7 (acinar) and 51.5±7.8 (duct) dpm/μg DNA. Alkylation persisted for longer in duct (t/2>46 h) than in acinar tissue (t/2=6 h). The faster repair of alkylation in acinar tissue was not due to acinar cell death. In rat duct tissue the level of alkylation 2 h after incubation (38.9±4.5 dpm/μg DNA) was similar to that in hamster ducts but declined more rapidly (t/2=27 h). Hamster and rat acinar and duct tissue was incubated with BOP followed by [3H]thymidine to measure DNA synthesis. BOP stimulated DNA synthesis in hamster but not in rat duct tissue or hamster acinar tissue. These data support the hypothesis that the duct tissue is the target tissue for BOP in Syrian hamsters.