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 microCi/ml) for 2 h. Initial levels of alkylation were similar, 41.7 +/- 3.7 (acinar) and 51.5 +/- 7.8 (duct) dpm/micrograms DNA. Alkylation persisted for longer in duct (t/2 greater than 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/micrograms 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.