[Effect of ascorbic acid on the hepatocarcinogenic action of N-nitrosodiethylamine in rats].

It is shown that the ascorbic acid (AA) administration to Wistar male rats (50 mg per animal intraperitoneally 3 times a week) accelerates hepatocarcinogenesis induced by N-nitrosodiethylamine (2.5 mg/kg 6 times a week in drinking water). In this case the activity of glucose-6-phosphate dehydrogenase in liver increases, while that of glucose-6-phosphatase decreases.

[Effect of ethanol on the hepatocarcinogenic action of N-nitrosodiethylamine in rats].

It is shown that the administration of ethanol to male Wistar rats (3 g/kg by gastric tube 3 times a week for 2 months) before or at the beginning of the N-nitrosodiethylamine (NDEA) treatment (2.5 mg/kg 6 times a week in drinking water) reduces the hepatocarcinogenicity of NDEA. This was expressed macroscopically by less important neoplastic changes and biochemically by the higher glucose-6-phosphatase and lower glucose-6-phosphate dehydrogenase activities in the liver.

[Characterization of cytosol and nuclear glucocorticoid receptors from rat liver tissue in hepatocarcinogenesis].

Specific receptors with high affinity for dexamethasone (Kass = 2.03 = 4.04 .

[Changes in the isoenzymatic makeup of pyruvate kinase in hepatic carcinogenesis].

Together with an increase in the total activity of pyruvate kinase, alterations in the isoenzyme spectrum were observed in hepatocarcinogenesis caused by treatment of rats with diethylinitrosamine. The alterations might be divided into two steps: initial, reversible changes and changes immediately related to development of the blastomatous process. The total activity of pyruvate kinase was gradually increased with appearance of hyperplastic symptoms as well as of primary tumoral foci in liver tissue.

[Sensitivity of hexokinase and glucokinase to hormonal action during hepatocarcinogenesis].

Effects of hydrocortisone and insulin on activities of hexokinase and its isoenzymes and on glucokinase activity were studied in hepatocarcinogenesis, induced in rats by diethyl nitrosamine. After administration during 7 days of hydrocortisone into normal rats the hexokinase was inactivated by 25% due to decrease in activity of the II isoenzyme. In this case activity of glucokinase was decreased by 38% in young animals and--by 23% in older animals.