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V N Gobeev

Publications and source records attributed to V N Gobeev.

9 recordsLinked to original sources
PubMed1976

[Biochemical characteristics determining the rates of tumour growth in the organism].

Experimental data suggest that contrary to the findings obtained for normal and regenerating liver of mouse, the greater part of hexokinase (HK) in transplantable hepatomas is firmly bound to mitochondrial membranes. It is shown that the ratio of the bound HK activity (HKbound) to that of total HK activity (HKtotal) diminishes with a hepatoma growth. Malignization of hepatocytes also leads to a sharp decrease in the cytochrome oxidase (CO) octivity. Though the data obtained are well-correlated with the Warburg hypothesis, there is no direct correlation between the malignancy of hepatomas evaluated by their growth rates, and the biochemical parameters of the tumours studied. On the basis of fundamental principles of Warburg's, it is proposed to evaluate energy metabolism of hepatomas by the activity and subcellular distribution patterns of HK as well as be the activity of CO, according to the expression: [(HKtotal)2//HKbound-CO+HKbound-CO]. It is demonstrated that there exists a certain linear dependence between the integral characteristics of hepatoma energetics and their growth rates.

Animals↗
PubMed1976

[On hexokinase isozymes].

Electrophoretic study of hexokinase (HK) associated with the soluble fraction of mouse transplantable hepatoma 22a revealed that almost all bands of HK activities overlapped the bands of glucose-6-P dehydrogenase (G6PDH) activities in the gels. Similar results were obtained for liver, muscle and brain soluble fractions, as well as for various extracts from hepatoma 22a mitochondria and commercial preparation of yeast HK. A single type of HK, which does not overlap G6PDH activity, was located between types I and II (according to the Katzen classification) as a diffuse band of 1 hour manifestation. A possibility of structural organization of glycolytic enzymes in the cell essential for the quantitative estimation of the isozyme pattern is discussed.

Animals↗
PubMedDate not supplied

[Possible significance of hexokinase binding to mitochondrial membranes].

A magnitude of the Pasteur's effect and content of bound hexokinase were studied in various malignant and normal tissues. In all cases studied these two values were practically the same. Dynamics of changes in subcellular localization of hexokinase and the Pasteur's effect were similarly altered in liver tissue during ontogenesis. Binding hexokinase with mitochondrial membranes was assumed to be the cytophysiological mechanism for regulation of glycolytic activity by respiration.

Animals↗
PubMedDate not supplied

[Subcellular distribution of hexokinase in hepatoma and its electrophoretic properties].

In hepatomas of various malignancy contrary to normal and regenerating liver tissue a considerable part of hexokinase (HK) activity was bound with mitochondria. The HK activity, estimated in nuclei, microsomes and apparently in cytoplasma membranes, was due to contamination with mitochondrial fraction. High specific activity of HK in mitochondria of tumors might be responsible for the increased glycolysis, when these organelle preparations were added to the soluble fraction of cells. The HK of tumors was extracted from the preparations by alternative pathways. Reversible binding of some part of the enzyme with mitochondria was regulated by concentration of metabolites (ATP and G6P) similarly to the bound HK from normal tissues (brain, retina). At the same time the other part of unregulated HK activity (isozyme I only) was found in hepatomas to be intercalated into lipoprotein membranes; it was not controlled by metabolites.

Animals↗
PubMedDate not supplied

[Biochemical features of the liver of high and low cancer mouse strains and primary spontaneous hepatomas].

Sex differences in development of spontaneous liver tumors were studied in mice of CBA strain. Content of mitochondrial proteins, activities of cytochrome oxidase, glucokinase, hexokinase as well as subcellular distribution of hexokinase were also studied in primary hepatomas and in normal liver tissue of the mice of CBA and C3HA strains. Liver tumors occurred in males of CBA strain 7-fold more frequently than in females. Activities of hexokinase, glucokinase, cytochrome oxidase and content of mitochondrial proteins were distinctly alterep both in primary spontaneous hepatomas and in transplantable strains. But, contrary to the transplantable tumors, in spontaneous hepatomas hexokinase, associated with mitochondria, was not found. Decrease in activities of glucokinase and cytochrome oxidase was observed at the early stages of development of CBA strain in males as compared with females of CBA and males of C3HA strains, i.e. distinct decrease in several functional patterns of liver tissue was observed. Subcutaneous administration of orthoamine azotoluene into mice of the C3HA strain caused alteration in activity of these enzymes from liver tissue, which was typical for hepatomas, already at the early steps of development.

Age Factors↗
PubMedDate not supplied

[Activity of the key glycolysis and respiration enzymes in the rat liver in chemical carcinogenesis].

Activities of hexokinase, glucokinase, cytochrome oxidase as well as amount of mitochondrial protein and subcellular distribution of hexokinase were studied in rat liver tissue after administration of acetyl aminofluorene and diethyl nitrosamine. Activity of the enzymes was altered in the same direction both in the primary induced hepatomas and in transplantable tumors of liver tissue. Glucokinase was not found but the fraction of hexokinase bound to mitochondrial membranes was observed in all the primary hepatomas studied; in this property the tumors resembled the embryonal liver tissue, various tissues of mature animals and transplantable hepatomas. This pattern of distribution of the enzymes reflects biochemical and functional disdifferentiation of the hepatomas. Properties of the bound hexokinase from the hepatoma were similar to those of the enzyme from embryonal liver tissue and, hence, they were distinct as compared with the enzymatic properties of hexokinase in the transplantable hepatomas.

2-Acetylaminofluorene↗