[Cytochemical analysis of polyamines in Ehrlich ascitic carcinoma cells during different phases of mitotic cycle under the effects of difluoromethylornithine].

Mice bearing Ehrlich carcinoma cells received one 80 mg/kg dose of DFMO. After 20 hours the cells were extracted from the peritoneal cavity and separated by means of sedimentation of 1 g in saccharose gradient into 9 fractions depending on the mitotic cycle phase. The content of polyamines in the cells of each fraction was detected by the fluorescent method using fluorescamine.

[Effects of vitamin A on the activity of glutathione system enzymes of liver detoxication after administration of nitroso-compound precursors to rats].

The activity of glutathione system enzymes exposed to nitroso-compound (NC) precursors in small doses for 12 months and preliminary injection of vitamin A have been studied. The histo- and biochemical examinations have revealed a pronounced increase in the enzyme activity exposed of NC precursors and a slight increase when injecting preliminary vitamin A.

[Effect of preparations of unsaturated fatty acids on the lipid component of the endoplasmic reticulum membranes of liver cells in rats following administration of N-nitrosodiethylamine].

The effect of drugs, including unsaturated fatty acids and antioxidants, on the lipid composition of the endoplasmic reticulum membranes was studied at early stages of NDEA-induced hepatocarcinogenesis. The complexes containing oleic, linoleic, and arachidonic acids and biological antioxidants prevent changes in the fatty acid composition and the lipid bilayer organization of the both membrane fractions of endoplasmic reticulum which are observed after the injection of NDEA alone, and they inhibit the appearance and growth in the liver of gamma-glutamyltranspeptidase positive hyperplastic nodules.

[Characteristics of hepatocarcinogenesis after single exposure of synchronized cells of the regenerating liver to N-nitrosodiethylamine and subsequent administration of phenobarbital].

The frequency of tumour incidence in rats subjected to the single action of diethylnitrosamine to regenerating liver cells synchronized in different phases of the mitotic cycle was maximal in rats exposed to carcinogen when 62.5% of regenerating liver hepatocytes were in the S-phase. Dietary added phenobarbital increased the number and size of hepatocarcinomas especially in rats which received DENA in the G2-M phase of hepatocytes or during maximal proliferation of nonparenchymal cells.

[Sensitivity of rat hepatocytes to phenobarbital after a single dose of N-nitrosodiethylamine in the embryonal and postnatal period or after partial hepatectomy].

For the hepatocarcinogenesis initiation one-fold N-nitrosodiethylamine (NDENA) action upon the livers of embryos and of the 4-weeks rats, before or after partial hepatectomy was used. Phenobarbital and repeated partial hepatectomies were used as the promotive factors. The promotion effect was evaluated by the quantity and size of hyperplastic liver nodules, where gamma-glutamyltranspeptidase activity was revealed.