No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
The effect of physical load of varying intensity on the activity of liver enzymes and hepatocytes’ proliferation
Abstract
The paper establishes the relationship between enzymatic activity and the proliferation of hepatocytes. Low-intensity physical activity is shown not to influence the activity of hepatocytes’ enzymes and their proliferation. Hard work results in decreased activity of redox enzymes; at the same time, the proliferation of hepatocytes is inhibited for a long time. The most favorable is moderate load, which leads to the activation of oxidative-reducing enzymes and increases the number of binucleated hepatocytes, which persist for a long time after the end of the experiment.
ResearchGate has not been able to resolve any citations for this publication.
Background. Changes in the architecture of the hepatocyte nucleus resulting from liver tissue exposure to pathogens have diagnostic and prognostic signifcance. In morphological study of liver tissue in chronic HCV infection there is a diffcult with the viability assessment of hepatocytes and their organelles in the presence of various mechanisms of nonprogrammed and controlled cell death. Objective. To present the data available in literature and the results of our own studies of structural architecture of hepatocyte nuclei and their components in chronic hepatitis C (CHC). Material and methods. The intravital liver bioptates of 18 patients with CHC (who had given a written informed consent) were studied. Some visualization methods were used: light and electron microscopy, including examination of semi-thin sections, various methods of fxation and staining. Results. The results of the authors’ morphological studies are presented, demonstrating some changes in structural and functional characteristics of the nuclear apparatus of hepatocytes and nuclear components with a detailed description and interpretation of the changes (polyploidy, nuclear envelope, nucleoplasm, chromosomes, perichromatin fbrils, interchromatin and perichromatin granules, nucleolus, nucleolar stress and replication others). Conclusion. In chronic HCV infection, changes occur in all components of the nuclear apparatus characterizing structural and functional features of hepatocytes. The assessment of architectural organization of the nuclear apparatus in hepatocytes provides pathomorphologists and clinicians (hepatologists) with valuable additional data indicating the applied signifcance of the changes in the parameters of the nuclear apparatus of hepatocytes in CHC, that in its turn, will contribute to more accurate monitoring of the infectious process and accelerated diagnosis of its transformation into malignant growth.
Eukaryotic organisms usually contain a diploid complement of chromosomes. However, there are a number of exceptions. Organisms containing an increase in DNA content by whole number multiples of the entire set of chromosomes are defined as polyploid. Cells that contain more than two sets of chromosomes were first observed in plants about a century ago and it is now recognized that polyploidy cells form in many eukaryotes under a wide variety of circumstance. Although it is less common in mammals, some tissues, including the liver, show a high percentage of polyploid cells. Thus, during postnatal growth, the liver parenchyma undergoes dramatic changes characterized by gradual polyploidization during which hepatocytes of several ploidy classes emerge as a result of modified cell-division cycles. This process generates the successive appearance of tetraploid and octoploid cell classes with one or two nuclei (mononucleated or binucleated). Liver cells polyploidy is generally considered to indicate terminal differentiation and senescence and to lead both to the progressive loss of cell pluripotency and a markedly decreased replication capacity. In adults, liver polyploidization is differentially regulated upon loss of liver mass and liver damage. Interestingly, partial hepatectomy induces marked cell proliferation followed by an increase in liver ploidy. In contrast, during hepatocarcinoma (HCC), growth shifts to a nonpolyploidizing pattern and expansion of the diploid hepatocytes population is observed in neoplastic nodules. Here we review the current state of understanding about how polyploidization is regulated during normal and pathological liver growth and detail by which mechanisms hepatocytes become polyploid.
In understanding mechanisms of liver repopulation with transplanted hepatocytes, we studied the consequences of hepatic polyploidization in the two-thirds partial hepatectomy model of liver regeneration. Liver repopulation studies using genetically marked rodent hepatocytes showed that the number of previously transplanted hepatocytes did not increase in the liver with subsequential partial hepatectomy. In contrast, recipients undergoing partial hepatectomy before cells were transplanted showed proliferation in transplanted hepatocytes, with kinetics of DNA synthesis differing in transplanted and host hepatocytes. Also, partial hepatectomy caused multiple changes in the rat liver, including accumulation of polyploid hepatocytes along with prolonged depletion of diploid hepatocytes, as well as increased senescence-associated beta-galactosidase and p21 expression. Remnant hepatocytes in the partially hepatectomized liver showed increased autofluorescence and cytoplasmic complexity on flow cytometry, which are associated with lipofuscin accumulation during cell aging, and underwent apoptosis more frequently. Moreover, hepatocytes from the partially hepatectomized liver showed attenuated proliferative capacity in cell culture. These findings were compatible with decreased proliferative potential of hepatocytes experiencing partial hepatectomy compared with hepatocytes from the unperturbed liver. Attenuation of proliferative capacity and other changes in hepatocytes experiencing partial hepatectomy offer novel perspectives concerning liver regeneration in the context of cell ploidy.
The onset of cellular polyploidy is recognized in all differentiated mammalian tissues. Polyploidy has been noted frequently in the normal liver, as well as in pathophysiological states of the liver. As insights into the significance of polyploidy accumulate gradually, it is becoming clear that cells belonging to high ploidy classes exhibit advancement toward terminal differentiation and cellular senescence with greater probabilities of apoptosis. Involvement of specific genetic abnormalities, such as impaired DNA repair, may lead to hepatocellular polyploidy. Working models indicate that extensive polyploidy could lead to organ failure, as well as to oncogenesis with activation of precancerous cell clones.
Viscosity and elasticity of the cardiovascular system are assessed by a new method based on evaluation of correlations between deposit properties of the left ventricular chamber, aortic wall and vascular resistance in different parts of the arterial tree. This method examines individual hemodynamic characteristics of healthy untrained persons and hemodynamic changes due to regular training.
To elucidate the functional significance of genome multiplication in somatic tissues, we performed a large-scale analysis of ploidy-associated changes in expression of non-tissue-specific (i.e., broadly expressed) genes in the heart and liver of human and mouse (6585 homologous genes were analyzed). These species have inverse patterns of polyploidization in cardiomyocytes and hepatocytes. The between-species comparison of two pairs of homologous tissues with crisscross contrast in ploidy levels allows the removal of the effects of species and tissue specificity on the profile of gene activity. The different tests performed from the standpoint of modular biology revealed a consistent picture of ploidy-associated alteration in a wide range of functional gene groups. The major effects consisted of hypoxia-inducible factor-triggered changes in main cellular processes and signaling pathways, activation of defense against DNA lesions, acceleration of protein turnover and transcription, and the impairment of apoptosis, the immune response, and cytoskeleton maintenance. We also found a severe decline in aerobic respiration and stimulation of sugar and fatty acid metabolism. These metabolic rearrangements create a special type of metabolism that can be considered intermediate between aerobic and anaerobic. The metabolic and physiological changes revealed (reflected in the alteration of gene expression) help explain the unique ability of polyploid tissues to combine proliferation and differentiation, which are separated in diploid tissues. We argue that genome multiplication promotes cell survival and tissue regeneration under stressful conditions.
Microcirculation under stress. Pathological physiology and experimental therapy
- M P Gorizontova
Gorizontova MP. Microcirculation under stress. Pathological physiology and
experimental therapy. 1986; 3: 79-84.
Dyslipidemia during chronic physical exertion of varying intensity. Fundamental research
- E N Ermolaeva
- L V Krivokhizhina
Ermolaeva EN, Krivokhizhina LV. Dyslipidemia during chronic physical exertion
of varying intensity. Fundamental research. 2015; 1147-1151.
Occupational medicine and prom. Ecology. The state of health of high-class athletes in various sports
- O S Kogan
Kogan OS. Occupational medicine and prom. Ecology. The state of health of
high-class athletes in various sports. 2006; 5: 40-44.
Histomorphological assessment of the hepatoprotective effect of phytoadaptogens in toxic damage to the liver of mice by carbon tetrachloride against the background of intense physical activity
- P I Gennadievna
- S V Kozin
- D V Bulanov
Gennadievna PI, Kozin SV, Bulanov DV. Histomorphological assessment of
the hepatoprotective effect of phytoadaptogens in toxic damage to the liver
of mice by carbon tetrachloride against the background of intense physical
activity. Bulletin of VolGMU. 2014; No. 2 (50). URL: https://cyberleninka.ru/
article/n/gistomorfologicheskaya-otsenka-gepatoprotektornogo-deystviyafi toadaptogenov-pri-toksicheskom-porazhenii-pecheni-myshey
(date
of
access: 09/29/2022).
Structure of the liver at the combined impact of chemicals on the organism
- Umbetov Tzh
- A K Berdalinova
- K E Zharilkasinov
- L Chizmanidi
- N Baldakov
Umbetov TZh, Berdalinova AK, Zharilkasinov KE, Chizmanidi L, Baldakov N.
Structure of the liver at the combined impact of chemicals on the organism.
Bulletin of Medical Internet Conferences (ISSN 2224-6150) 2016; 6.
Cellular polyploidy. Proliferation and differentiation
- Brodsky Vya
- I V Uryvaeva
Brodsky VYa, Uryvaeva IV. Cellular polyploidy. Proliferation and differentiation.
Science. 259.
Reactive changes in the blood system and oxidative stress during physical activity of varying intensity. Abstract of the dissertation for the degree of Doctor of Medical Sciences
- E N Ermolaeva
Ermolaeva EN. Reactive changes in the blood system and oxidative stress
during physical activity of varying intensity. Abstract of the dissertation for the
degree of Doctor of Medical Sciences. 2020; 42.
Histochemistry of enzymes. Laboratory methods
- Z Loida
- R Gossrau
- T Schibler
Loida Z, Gossrau R, Schibler T. Histochemistry of enzymes. Laboratory
methods. Moscow: Mir Publ. 1982; 272.