C57BL/6 mice are relatively more resistant to hepatocarcinogens than C3H and C57BL/6 x C3H F1 (hereafter called B6C3F1) mice; however, the basis for this strain-dependent difference is not clear. In order to address this issue, male C57BL/6 mice were treated i.p. with 5 mg/kg diethylnitrosamine when 15 days old and the histological features of induced hepatocellular neoplasms were assessed at i...

The presence of glutathione was demonstrated histochemically in livers of rats treated with diethylnitrosamine or N-nitrosomorpholine. Glutathione content was markedly elevated in adenosine triphosphatase-deficient, gamma-glutamyltranspeptidase-positive hyperplastic cell islands. This finding may partly explain the increased resistance of hyperplastic cells to cytotoxic actions of hepatocarcino...

The effect of dietary exposure to synthetic estrogens on hepatocarcinogenesis was evaluated. Diethylnitrosamine-initiated and 0.85% NaCl solution-treated noninitiated female Sprague-Dawley rats were transferred to semisynthetic diets containing mestranol (0, 0.1, or 0.5 ppm), ethinyl estradiol (0.5 ppm), estradiol (0.6 ppm), or mestranol plus beta-methasone (0.5 and 0.2 ppm, respectively). gamm...

Ten organosulfur compounds from garlic and onions were studied for their modifying effects on diethylnitrosamine-induced neoplasia of liver in male F344 rats using the medium-term bioassay system of Ito based on the two-step model of hepatocarcinogenesis. Carcinogenic potential was scored by comparing the number and area per cm2 of induced glutathione S-transferase placental form-positive foci ...

In order to evaluate the possible implication of the enzymatic competence of liver in the carcinogenesis by diethylnitrosamine, we assayed liver homogenates from 1-, 7-, 15-, 28-, 42-, and 70-day-old C57BLX C3H F! mice of both sexes for dealkylating activity. These studies were comple mented by a series of carcinogenesis bioassays in which 15and 42-day-old mice of the same strain were administe...

Dietary factors can modify metabolic events involved in the initiation, promotion, or progression of tumors. To determine whether a high-sucrose diet has any effect on the development of enzyme-altered foci during the promotion step of chemical hepatocarcinogenesis in rats, 1-day-old Sprague-Dawley rats were given a single i.p. dose of diethylnitrosamine; controls received an equivalent ¡.p. v...

Aim: Materials and Methods: