[Metabolic characteristics of xenobiotics in the liver of tumor-bearing rats]. / Osobennosti metabolizma ksenobiotikov v pecheni krys s opukholiami.

A study of the condition and function of a multienzymatic monoxygenase system in liver microsomes of rats bearing experimental Pliss' lymphosarcoma and Zajdela's ascites hepatoma showed synthesis and function of the key enzymes of the hydroxylating microsomes of the liver being inhibited and, consequently, drug metabolism slowed down.

[The role of pyridine nucleotide cofactors in the reaction of microsomal N-demethylation under normal conditions and in tumor pathology]. / Uchastie piridinnukleotidnykh kofaktorov v reaktsii mikrosomal'nogo N-demetilirovaniia v norme i pri opukholevoi patologii.

Functions of pyridine nucleotide cofactors NADPH and NADH in N-demethylation of amidopyrine were studied under conditions of normal and malignant states. Contribution of NADH-specific transfer of electrons to microsomal N-demethylation was gradually augmented in the sequence: microsomes from liver tissue of rats with Zajdela hepatoma--microsomes of ascites hepatocytes. In this sequence both synergic effect of these cofactors and the rate of N-demethylcation, if NADH was used as a cofactor, were increased.

[Inactivation and degradation of rat liver catalase by mitochondrial and lysosomal proteinases]. / Inaktivatsiia i degradatsiia katalazy iz pecheni krys mitokhondrial'nymi i lizosomal'nymi proteinazami.

The initial phases of catalase degradation in rat hepatocytes were studied. Preparations of highly purified fractions of lysosomes and mitochondria from rat liver were obtained. The proteinase activity was measured by the radio-isotope method by the increase of the free amino groups or by the decrease of the catalase activity, using labelled catalase as a substrate. It was found that the initial step of catalase degradation occurs in the enzyme localized in the inner membrane as well as in the mitochondrial matrix and that the total degradation of catalase is completed in the lysosomal fraction of rat liver.