glycogen and Cocarcinogenesis

The effects of malachite green (MG) and phenobarbitone (PB) were compared on the development of pre-neoplastic lesions during N-nitrosodiethylamine(DEN)-induced hepatocarcinogenesis in male Wistar rats. Rats were administered 200 p.p.m. DEN in drinking water for a period of 1 month. After an interval of 2 weeks the animals were given either MG (25 p.p.m.) or PB (500 p.p.m.) in drinking water for 2.5 months. The effects were monitored on the basis of the morphological appearance of the liver, histological pattern, gamma-glutamyltranspeptidase (GGT)-positive foci, total GGT activity and the induction of glycogen-deficient islands. Both MG and PB were found to enhance liver carcinogenesis to a significant extent when compared with either their corresponding controls or animals given DEN alone. The enhancing effect of MG at 25 p.p.m. is comparable with PB at 500 p.p.m. An enhancing effect of MG on DEN-induced hepatocarcinogenesis in the rats was demonstrated.

Topics: Animals; Cocarcinogenesis; Diethylnitrosamine; gamma-Glutamyltransferase; Glycogen; Liver; Liver Neoplasms, Experimental; Male; Organ Size; Precancerous Conditions; Rats; Rats, Inbred Strains; Rosaniline Dyes

Chloroform enhances dose-dependently the number of preneoplastic foci in livers of weanling female Sprague-Dawley rats. The preneoplastic foci were induced with a single dose of 8 mg diethylnitrosamine (DEN)/kg body wt. Thereafter chloroform was applied twice weekly for 11 consecutive weeks in doses of 100, 200 and 400 mg/kg body wt, respectively. This treatment raised the number of adenosine-5'-triphosphatase (ATPase)-deficient foci up to 5-fold, that of gamma-glutamyltranspeptidase (GGTase) and glycogen-positive foci 13- and 10-fold, respectively, after 12 weeks; 25 mg caused no effect compared to DEN-treated controls. In contrast, daily doses of chloroform only, 200 and 400 mg/kg body wt for 33 days, and 800 mg/kg body wt for 20 days given to 3-4-week-old female Sprague-Dawley rats did not lead to island formation, measured after 12 weeks, indicating a promoting rather than an initiating potency.

Topics: Adenosine Triphosphatases; Animals; Carcinogens; Chloroform; Cocarcinogenesis; Diethylnitrosamine; Female; gamma-Glutamyltransferase; Glycogen; Liver Neoplasms; Precancerous Conditions; Rats; Rats, Inbred Strains