Pathogenesis of dimethylnitrosamine-induced hepatocellular cancer in hamster liver and lack of enhancement by phenobarbital.
The early stages of dimethylnitrosamine (CAS: 62-75-9)-induced liver cancer and the effect of administration of phenobarbital (CAS: 50-06-6) after dimethylnitrosamine were studied in Syrian golden hamsters. A single ip injection of 6 mg dimethylnitrosamine/kg (body wt) induced hepatocellular altered foci by 6 months. Most foci were composed mainly of large clear glycogen-containing cells, while smaller numbers were formed by cells with abnormally acidophilic or basophilic cytoplasms. Biliary cysts, but not biliary neoplasms, also occurred. A few neoplastic (hyperplastic) nodules and hepatocellular carcinomas developed by 12 months. gamma-Glutamyltranspeptidase activity was not present in any of the hepatocellular lesions, but foci of all types, neoplastic nodules, and carcinomas were characterized by a lack of iron accumulation. Phenobarbital at 0.05% in the diet for up to 12 months did not increase the number of lesions of any type, indicating a lack of promoting effect under these conditions.
Stenbäck
F
F
Mori
H
H
Furuya
K
K
Williams
G M
GM
D000818:Animals; D001652:Bile Ducts / Q000187:drug effects / Q000473:pathology; D006224:Cricetinae; D004128:Dimethylnitrosamine; D006651:Histocytochemistry; D007501:Iron / Q000032:analysis; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced* / Q000473:pathology; D008647:Mesocricetus; D010634:Phenobarbital / Q000494:pharmacology; D013194:Staining and Labeling; D013997:Time Factors; D005723:gamma-Glutamyltransferase / Q000032:analysis
D007501:Iron; D005723:gamma-Glutamyltransferase; D004128:Dimethylnitrosamine; D010634:Phenobarbital