title: Modification of pancreatic carcinogenesis in the hamster model. 6. The effect of ductal ligation and excision.
abstract: The effect of ligation and excision of the pancreatic duct in pancreatic carcinogenesis was examined in the hamster model. Animals were treated with a single dose (20 mg/kg body weight) of N-nitrosobis(2-oxopropyl)amine (BOP) either immediately (Group 1) or on Days 1 (Group 2), 3 (Group 3) or 7 (Group 4) after ligation and excision of the duct of the splenic lobe. Group 5 received BOP shortly after laparoscopy, and Group 6 consisted of BOP-treated controls. All hamsters were killed 46 weeks after BOP treatment. The results showed that despite advanced atrophy of the splenic lobe distal to the excised duct in Groups 1-4, some hamsters in Groups 2, 3, and 4 showed hyperplasia, dysplasia, and increased mitotic activities of ductal and ductular cells. However, carcinomas in the duct-excised atrophic lobe were found only in Groups 1-3. These data indicate that BOP carcinogenesis is mediated through blood circulation, and that cancer development is not inhibited in the duct-excised lobe for up to 3 days after surgery. However, in the entire pancreas, a significant reduction in tumor incidence was seen when the carcinogen was given immediately, or to a lesser extent, 1 day after surgery, regardless of whether or not excision was made. On the contrary, BOP, when given 3 and 7 days after duct excision, enhanced tumor development in the nonexcised (intact) pancreas, compared with other test groups and with BOP controls. Both inhibition and enhancement seemed due to a proportional decrease and increase, respectively, of BOP-responsive cells throughout the intact pancreas.
mesh_terms: D000818:Animals; D006224:Cricetinae; D004195:Disease Models, Animal; D006965:Hyperplasia; D008026:Ligation; D008647:Mesocricetus; D008938:Mitosis; D009602:Nitrosamines; D010180:Pancreatectomy; D010183:Pancreatic Ducts / Q000601:surgery* / Q000648:ultrastructure; D010190:Pancreatic Neoplasms / Q000139:chemically induced* / Q000648:ultrastructure
chemical_list: D009602:Nitrosamines; C013622:nitrosobis(2-oxopropyl)amine