Further characterization of carcinogen-induced hepatocytelike cells in hamster pancreas

Regenerating pancreatic cells of the Syrian hamster treated at the peak of S phase with the pancreatic carcinogen N-nitrosobis(2-oxopropyl)amine (BOP) are converted into stable cells wtih morphologic and functional characteristics that are strikingly similar to those of differentiated hepatocytes. In this article the authors further document their hepatocytelike nature. Seventy-two hours after subtotal hepatectomy, pancreatic hepatocytelike cells responded with an 8-fold increase in labeled nuclei (105.8 +/- 4.04/1000 cells) which had incorporated 3H-thymidine and a 5-fold increased mitotic index (3.8 +/- 1.5 mitoses/1000 cells), as compared with similar cells in the pancreas of control animals that had undergone sham operations. Chronic administration of phenobarbital induced a 31-fold increase in the level of aryl hydrocarbon hydroxylase (AHH) in pancreas containing such cells, as compared with normal control pancreases, and caused marked proliferation of smooth endoplasmic reticulum (SER). These cells also showed an enhanced capacity for the accumulation of iron during acute iron excess, as compared with adjacent acinar cells. Collectively, these findings support the view that carcinogen-induced cells in pancreas bear a close functional resemblance to hepatocytes.