Promoting effects of phenobarbital and 3'-methyl-4-dimethylaminoazobenzene on the appearance of gamma-glutamyltranspeptidase positive foci in rat liver pretreated with varying doses of diethylnitrosamine.
The promotion potential of phenobarbital (PB) and 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) on liver carcinogenesis after initiation with various doses of diethylnitrosamine (DEN) was assessed using an in vivo short term system. Male F344 rats were pretreated with a single intraperitoneal injection of varying doses of DEN (0, 6, 12, 25, 50, 100 or 200 mg/kg body wt), and 2 weeks later were treated with 0.05% PB or 0.06% 3'-Me-DAB for 6 weeks. All animals were subjected to partial hepatectomy 3 weeks after the DEN treatment. Quantitation of gamma-glutamyltranspeptidase-positive (gamma-GT+) foci revealed a DEN dose-dependent response. Magnitude of promotion by PB and more pronounced by 3'-Me-DAB was, in contrast, strongest at the lower doses of DEN. The results suggest that quantitative differences with regard to initiation level may exist, influencing the promotability of initiated cells.
Shirai
T
T
Hosoda
K
K
Hirose
K
K
Hirose
M
M
Ito
N
N
D000818:Animals; D003043:Cocarcinogenesis; D004052:Diethylnitrosamine; D008099:Liver / Q000201:enzymology*; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced* / Q000201:enzymology; D008297:Male; D008749:Methyldimethylaminoazobenzene / Q000633:toxicity*; D009929:Organ Size / Q000187:drug effects; D010634:Phenobarbital / Q000633:toxicity*; D011230:Precancerous Conditions / Q000139:chemically induced* / Q000201:enzymology; D051381:Rats; D011916:Rats, Inbred F344; D005723:gamma-Glutamyltransferase / Q000032:analysis*; D004124:p-Dimethylaminoazobenzene / Q000031:analogs & derivatives*
D004052:Diethylnitrosamine; D008749:Methyldimethylaminoazobenzene; D004124:p-Dimethylaminoazobenzene; D005723:gamma-Glutamyltransferase; D010634:Phenobarbital