Biomedical subjects

B N Kudriavtsev

Publications and source records attributed to B N Kudriavtsev.

At least 19 recordsLinked to original sources

PubMed2005

[Cellular mechanisms of cirrhotic rat liver regeneration. II. Proliferation, polyploidization and hypertrophy after partial hepatectomy].

Using cytofluorimetry and absorptional cytophotometry, hepatocyte DNA and total protein contents were measured in intact and cirrhotic rats in 1, 3 and 6 months after partial hepatectomy (PH). It has been found that within one month of intact rat liver regeneration the level of hepatocyte ploidy rised by 25% to remain elevated for the next 6 months. This was due mainly to reducing the number of cells with diploid nuclei (2c 2-fold, 2c x 2 - 6.6-fold) and to rising the number of octaploid hepatocytes. In cirrhotic animals the ploidy level in hepatocytes increased in 3 months after PH, and decreased by 15% in 6 months. The number of hepatocytes with diploid nuclei (2c and 2c x 2) increased within 3-6 months in both control and cirrhotic rats. The protein content per diploid hepatocyte rised by 30% within 3-6 months of liver regeneration after PH. Special calculations have shown that within 3 months after PH the increase in the liver mass of control and cirrhotic rats was due completely to hepatocyte DNA synthesis, i. e. proliferation and polyploidization. Within the next 3 months of liver regeneration after PH, the contribution of polyploidization to liver mass increase was negative because of depolyploidization of liver parenchyma cell population. At this time hypertrophy was the main process determining the liver mass increase.

Animals↗

PubMed2005

[Kinetic features of a white rat hepatocyte population under hormonal disbalance before and after partial hepatectomy].

Bilateral adrenalectomy, followed in 4 days by a partial hepatectomy, was performed using white rats weighing as much as 120-140 g. Under hormonal disbalance caused by bilateral adrenalectomy, the number of polyploid (4c, 4c x 2, and 8c) hepatocytes significantly increased, compared to that in non-operated control rats. Six hours after a partial hepatectomy, the share of highly ploid hepatocytes falls, being accompanied by a 9-fold increase in mitotic index. It is supposed that under hormonal disbalance condition, a partial hepatectomy may induce "early" mitoses in hepatocytes blocked in G2-phase of the cell cycle.

Adrenal Glands↗

PubMed2004

[The influence of hepatoprotector 2-ethylthiobenzimidazole hydrobromide (bemithyl) on the content of glycogen in cirrhotic rat liver hepatocytes located in various microenvironments].

Using absorption and fluorescent cytophotometry methods, glycogen contents were studied in hepatocytes located in liver lobules and in hepatocytes, which make the general population of these cells in normal and cirrhotic rat liver. In cirrhosis, the content of glycogen in hepatocytes located in lobules obviously rises in comparison with the norm, but to a lesser degree, than in hepatocytes making the general population of these cells in cirrhotic liver. The content of glycogen in hepatocytes, located in lobules of pathologically changed liver in bemithyl treated rats, did not differ from the norm. At the same time, the glycogen content in hepatocytes, representing the general population of these cells in cirrhotically altered bemithyl injected rat liver, remained higher than in the norm. The data obtained indicate that distinctions in particular cell microinvironment, obviously present in cirrhotic liver, render essential influence on hepatocyte functional activity.

Animals↗

PubMed2003

[Dynamics of glycogen content in the normal and cirrhotic liver following glucose administration to starving rats].

Using biochemical, cytofluorimetric and television cytophotometric methods, glycogen contents were studied in normal and cirrhotic rat liver at various intervals after glucose administration to fasting animals. The obtained data indicate that after a 48 h fasting glycogen contents in normal and cirrhotic liver are equally poor. A marked rise of glycogen content in cirrhotic liver was observed only 20-30 min after glucose administration to rats. It has been established that at all intervals after glucose administration to rats hepatocytes of the portal lobule zone, both in normal and in cirrhotic liver, accumulate more glycogen than those of the central zone. Again, the intensity of glycogen accumulation in cirrhotically altered liver is significantly lower than in normal liver, due, presumably, to a lower rate of glycogen synthesis in pathologically changed liver.

Animals↗

PubMed2002

[Effect of bemythyl on carbohydrate metabolism in cirrhotic rat liver].

Effect of actoprotector bemitil (2-ethylthiobenzimidazole hydrobromide) on glycogen content and activities of glycogen synthase, glycogen phosphorylase, and glucose-6-phosphatase was studied in cirrhotically altered rat liver. The contents of glycogen and its fraction were determined a cytofluorimetrically (Kudryavtseva et al., 1974). In cirrhosis, the total glycogen content in hepatocytes increases by nearly 3 times, while the amount of a stable fraction of glycogen rises by 7.5 times. Glucose-6-phosphatase activity fell to the level of 25% compare to the norm. Activities of glycogen synthase and glycogen phosphorylase in the cirrhotic liver did not differ from the norm. In cirrhotically altered liver, bemitil produced a decrease in the total glycogen content due to a decrease in glycogen synthase activity in an increase in glucose-6-phosphatase and glycogen phosphorylase activities. The above results suggest a favorable effect of bemitil on cirrhotic liver.

Animals↗

PubMed2002

[Features of the effect of bemethyl on glycogen metabolism in hepatocytes of pathological changed human liver].

Effect of actoprotector bemithyl (2-ethylthiobenzimidazole hydrobromide) on glycogen metabolism in hepatocytes of patients with chronic hepatitis and liver cirrhosis was investigated. Using cytofluorimetric method, the content of glycogen and its fractions in isolated hepatocytes was measured. The treatment with bemithyl resulted in a decrease in glycogen levels in hepatocytes, and in a marked restoration of fractional glycogen composition as compared to the basic therapy. Besides, it was established that the degree of glycogen decrease in cells of patients with chronic hepatitis depended on the increase of glucose-6-phosphatase activity (r = 0.75, P < 0.05), and on the levels of glycogen in hepatocytes prior to bemitil treatment (r = = 0.87, P < 0.01). Positive changes in glycogen metabolism after bemithyl treatment are pronounced in patients with chronic hepatitis. These positive alterations take place simultaneously with the conservation of basic structural disturbances in the liver parenchyma. However, even in this case, the indices of glycogen metabolism do not reach the normal levels.

Antioxidants↗

PubMed2001

[Effect of partial hepatectomy on the glycogen level in hepatocytes in the portal and central lobule zones in cirrhotically-changed rat liver].

Using cytophotometric method, the content of glycogen was studied in hepatocytes of the portal and central zones of a liver lobule in norm, in cirrhosis, and 1, 3, and 6 months after a partial hepatectomy of the normal and cirrhotic rat liver. As we showed earlier, glycogen content in cirrhotic liver hepatocytes rose 2-3-fold, along with obvious impairment of glycogen metabolic heterogeneity in these. In cirrhotic liver glycogen dominates in the central zone, whereas in norm more glycogen is observed in the portal one. The objective of this study was to find out to what degree a partial hepatectomy of cirrhotic liver may promote recovery of the metabolic glycogen heterogeneity in hepatocytes. Glycogen was determined in hepatocytes, using a quantitative variant of PAS-reaction on sections of the material obtained from serial supravital punctate liver biopsies. Glycogen amount in hepatocytes of different liver lobule zones was determined by an image analyzer technique that allows to bring together the cytophotometric analysis of the substance with its localization in a particular liver lobule. Results of these studies have shown that a partial hepatectomy of cirrhotic liver promotes restoration of the hepatocyte metabolic heterogeneity in the liver lobule.

Animals↗

PubMed2000

[Toxicity of magnetite-dextran particles: morphological study].

Females of OFI mice were given single repeated intravenous injections of magnetite-dextran nanoparticles (MD3), the total partical diameter being 49 nm, with the magnetic core diameter equal to 10-15 nm. MD3 is a superparamagnetic preparation commonly used for magnetic resonance imaging (MRI). The liver, spleen, heart, kidney, and lung microstructures of these mice were determined after MD3 administration. Both dose- and time-dependent changes in the examined organs were compared after single and repeated MD3 doses. MD3 induces an increse in ferritine and iron levels in all the organs, the appearance of small aggregates of lymphoid cells in the liver, the appearance of iron-containing cell formations in hepatic sinusoids, presumably composed of the Kupffer cells and portal macrophages, splenomegaly, and hemostasis of spleen blood vessels. The pronounced morphological alterations have been revealed primarily in the liver and spleen after a single administration of high MD3 doses and after repeated MD3 injections. The results of The present investigation seem to narrow somewhat the safety limits of superparamagnetic iron oxide particles. Nevertheless, the degree of morphological changes in the liver and spleen in our experiments appeared to be rather low even after a single MD3 dose that exceeds approximately by 200 times a dose necessary for diagnostics in MRI.

Animals↗

PubMed2000

[Metabolic heterogeneity of glycogen in hepatocytes of patients with liver cirrhosis].

Concentrations of the total glycogen (TG) and of its labile and stable fractions (LF and SF, respectively) were determined in hepatocytes of portal and central zones of the normal human liver and in the liver of patients with cirrhosis of viral and alcohol etiology. Using the PAS reaction, TG and its LF and SF were revealed in histological sections of the material obtained by liver punction biopsies. Concentrations of TG and its fractions were measured by television cytophotometry. In liver cirrhosis, concentrations of TG, LF, and SF in both zones of the hepatic lobule were much higher than in the normal liver. The ratio between hepatocyte TG concentration in the portal zone and that in the central zone (P/C ratio), both in norm and in viral cirrhosis, exceeds 1.0 to reach, respectively, 1.26 +/- 0.02 and 1.03 +/- 0.01. The glycogen fraction composition in cells of both liver lobule zones in viral cirrhosis does not significantly differ from that in norm. On the contrary, in the liver of patients with alcoholic cirrhosis, the P/C ratio falls to 0.82 +/- 0.02 to be accompanied by qualitative changes in glycogen composition.

Humans↗

PubMed2000

[Effect of "vilon" on cirrhotically changed rat liver. Liver regeneration, and status of glycogen-forming function of hepatocytes].

Effects of a dipeptide preparation "Vilon" on rehabilitation of functional activity of hepatocytes and regeneration of the cirrhotically altered rat liver were studied. The liver cirrhosis was produced by poisoning of rats for 4 months with carbon tetrachloride (CCl4). On the end of the poisoning with CCl4, one group of animals was not submitted to any further actions, whereas animals of the other group were injected "Vilon" (1.7 micrograms/kg) daily for 5 days. On smears of isolated hepatocytes, contents of total glycogen (TG), and its labile and stable fractions (LF and SF) were determined in addition to cell ploidy levels and the total protein content. In liver homogenates, activities of glucose-6-phosphatase (G6P), glycogen synthase (GS), and glycogen phosphorylase (GP) were measured. In 2 weeks after the drug application, G6P activity being reduced in cirrhosis 1.2 times, elevated under effect of "Vilon". In non-treated rats the contents of TG and its fractions and of G6P activity remained at the level characteristic of the cirrhotic liver prior to "Vilon" administration. In both groups of rats, GP and GS activities in the cirrhotically altered liver did not differ from their control values throughout the entire experiment. "Vilon" has been shown to exert a weak stimulating effect on regeneration of the cirrotically altered rat liver: in hepatocytes of the second group of rats the total protein content and ploidy levels were higher than those in the first group by 4.7 and 11.5%, respectively.

Animals↗

PubMed1999

[Change in morphometric parameters in silver-stained nucleoli from hepatocytes of rats with liver cirrhosis and during rehabilitation from it].

Silver-stained nucleoli of rat hepatocytes were studied in norm, in liver cirrhosis produced by CCl4 poisoning and after cessation of the poisoning. Morphometric parameters of nucleoli were measured using a Videotest computer image analyser. Under cirrhosis the mean number of nucleoli per nucleus was determined to exceed their normal number by 1.27 times. The total volume of nucleoli in the nucleus also exceeded the normal level (by 1.15 times). 3 months after the end of CCl4-poisoning, these parameters decreased almost to normal values. A statistically significant correlation was revealed between the number of nucleoli and their total volume (0.881). Changes of the parameters also correlated with the total protein content in the hepatocytes. Possible reasons for this correlation are discussed. The ratio of the number of chromosomal NORs to the mean number of nucleoli in the nucleus is proposed to be used as a feature for comparative analysis of functional status of nucleoli in the nuclei of different ploidy and in cells of different animal species.

Animals↗

PubMed1999

[Glycogen synthesizing function of hepatocytes in rats with liver cirrhosis after treatment with chorionic gonadotropin].

Using rat liver hepatocytes, methods of cytofluorimetry (Kudryavtseva et al., 1974) and biochemistry were applied to comparative studies of the total glycogen content, including its labile (LF) and stable (SF) fractions, and activities of glucose-6-phosphatase, glycogen phosphorylase and glycogensynthetase in these. The liver hepatocytes were examined in norm, and under conditions of CCl4 poisoning of rats, both 6 months after a chronic poisoning, and 1, 3 and 6 months following poisoning cessation. All the experimentally poisoned rats were divided into two conventional groups: rats of one group received, apart from poisoning, a complex treatment with chorionic gonadotropin (CG); the other group rats received, no treatment. The material used for examination was obtained from serial functional biopsies of each experimental animal. It has been shown that under cirrhosis the content of the total glycogen in hepatocytes increased by 3 times, and that of its SF even by 9.7 times. The treatment with CG for 1 month resulted in its reducing to the norm, and 3 to 6 months treatments normalized contents of both the glycogen fractions. In the group of non-treated rats no similar changes were registered. Besides, in the cirrotic rats the activity of glucose-6-phosphatase was shown to increase by 4 times. After CG treatment it was seen to decrease by 3 times. Thus, CG may be regarded as an optimum and more effective agent for restoring abnormalities in cirrotic liver, compared to some other stimulating factors, such as hepatectomy (Kudryavtseva et al., 1996) or rich-carbohydrate diet (Kudryavtseva et al., 1998).

Animals↗

PubMed1998

[Rehabilitation of the hepatocyte glycogen-forming function in the rat cirrhotic liver due to carbohydrate rich diet].

By cytofluorometric and biochemical methods the content of total glycogen and its fractions was investigated on the smears of isolated liver cells: labile fraction (LF) and stable fraction (SF) and also activities of glycogen phosphorylase (GP), glucose-6-phosphatase (G-6-Pase) and glycogen synthase. The material was obtained from serial liver biopsies from each investigated animal prior to CCl4 action (control), with cirrhosis (6 months of CCl4 poisoning) and 1, 3 and 6 months after CCl4 poisoning was finished. It was shown that chronic CCl4 poisoning induced a typical liver cirrhosis accompanied with the 2-3 times increase in the total glycogen content, in comparison with the norm, with the decrease in LF to 53%, and also with the fall of G-6-Pase and GP activities by 82 and 25%, resp. After 1, 3 and 6 months following poisoning cessation, the lobule structure, infringed due to cirrhosis, was not restored. But functional parameters of the cirrhotic liver were seen gradually recovering without CCl4 poisoning. The application of carbohydrate rich diet favoured a most complete rehabilitation: the content of total glycogen and its fractions and the activity of G-6-Pase and GP returned to the normal level.

Animals↗

PubMed1998

[Cellular mechanisms of postnatal growth of rat liver in during chronic exposure of cadmium sulfate and strontium chloride].

A cytophotometric investigation was performed to study the ploidy level and total protein content in hepatocytes of rats of different ages (1, 7, 14, 21, 30, 90, 180, 365 days), both intact and chronically treated with cadmium sulfate or strontium chloride. It was established that during the first month of postnatal ontogenesis, compositions of liver parenchyma cell population of intact and treated rats did not differ. Compared to control animals, the process of cell polyploidization in the liver of rats treated with heavy metal salts of 30-90 days proceeded slower, especially in Cd(2+)-treated rats. Within 180-365 days the cell polyploidization in the treated animals increased. The proportion of (4c x 2)-hepatocytes in 1 year old Cd(2+)- or Sr(2+)-treated rats increased, resp., by 2.7 and 1.5 times, and that of 8c hepatocytes was higher by 3.9 and 1.5 times than in the control, the average ploidy level rising by 20 and 5%. respectively. It was established that until 90 days the rate of protein accumulation in liver cells of intoxicated rats was slower than in intact animals. Thus, the average protein content per diploid hepatocyte in Cd(2+)- or Sr(2+)-treated 30 day old rats was lower by 20 and 16%, respectively, compared to control animals. The protein content increased in liver cells of Cd(2+)- or Sr(2+)-intoxicated rats following 90 and 180 days, respectively, and this process was exclusively associated with cell polyploidization. During the first 3 weeks after birth, no significant difference was observed in the extent of involvement of cell proliferation, polyploidization and hypertrophy in the growth of liver in intact and intoxicated animals. At this period the liver was growing due completely to cell proliferation and hypertrophy. During 21-30 days the contribution of cell proliferation to the liver growth of intact rats was not significant (29%), whereas it remained at higher level (50%) in the treated animals. In 30-90 days after birth, the involvement of proliferation process to the liver growth of intoxicated rats decreased to 25-28%, while in intact animals it increased up to 37%. At this period the cell polyploidization plays an essential role in the growth of liver in both intact and intoxicated animals to reach in average 37-46%. The contribution of polyploidization and hypertrophy to the liver growth of Cd(2+)-treated rats within 30-90 days was obviously higher than in Sr(2+)-treated animals. Both at the late (3-12 months) and at the early (1-21 days) stages of experiments, the pattern of correlation of different cell components in the growing liver of intact and intoxicated rats differed only a little.

Administration, Oral↗

PubMed1998

[Effect of cadmium sulfate and strontium chloride on the glycogen content in hepatocytes of rats of various ages].

Cytophotometry and image analysis being used, hepatocyte glycogen contents were measured in periportal and pericentral zones of liver lobules at different stages (1, 7, 14, 21, 30, 90, 180 and 365 days) of postnatal development of both intact rats and rats exposed to chronic CdSO4 (1 mg/kg body weight) and SrSO4 (6.5 mg/kg body weight) intoxication. The glycogen content in hepatocytes of intact rats increased continuously in the course of development being most highest at the initial stage of development. The glycogen content ratio in cells of portal and central zones of liver lobules varied during ontogenesis. The maximum value of this ratio is reached on the 21st day after the rat birth, dropping sharply at later age to reach its minimum in adults. Intoxication of rats by Cd2+ and Sr2+ within 1-90 days interval reduced hepatocyte glycogen levels, compared to normal liver. The prolongation of rat treatment with heavy metals for 90-365 days led to glycogen accumulation in hepatocytes. Rat intoxication with heavy metals for 1 year brought about the increase in both glycogen content per cell and glycogen concentration. Cd2+ treatment for 30-90 days resulted in glycogen accumulation inhibition in both the investigated zones of liver lobules. Thereafter an increased glycogen accumulation took place in hepatocytes of the portal and central liver lobules. Following Cd2+ treatment, the value of the ratios of glycogen levels in the portal and central liver lobules was lower than in the normal liver on all stages of the postnatal rat development. The lowest value (< 1.0) of this ratio was reached in the cirrhotic liver. Distinct from Cd2+ treatment of rats, the treatment with Sr2+ does not lead to significant changes in glycogen levels in cells of different zones of liver lobules. Nevertheless certain destructive changes in glycogen-forming function of hepatocytes after Sr2+ treatment are apparent. This is suggested from the lower glycogen levels in the portal and central zones of liver lobules on 30-180 days interval compared to the normal liver. Besides, the values of ratios in glycogen levels in the portal and central zones of liver lobules in 14 and 21 days old rats was noticeably lower than in the intact rats of the same age.

Aging↗

PubMed1998

[Potential of the image analyzer "videotest" for performing microphotometric study in cytology].

Precision features of image analyser "Videotest" and possibilities of its applications for cytophotometric investigations have been analysed. It has been shown that a photometric feature is linear at least to optical density 1.1. Cytophotometry of the Feulgen stained rat hepatocyte nuclei has been performed. Coefficients of variation of DNA for 2c, 4c and 8c nuclei are 7.72, 7.65 and 6.50%, respectively, and ratios between average values of these nuclei are 1.00:2.06:4.12. Possible causes of errors of digital television equipment for cytophotometry are discussed.

Animals↗

PubMed1997

[Interconnection of parameters of the mitochondrial and myofibrillar apparatus of cardiomyocytes and ploidy and hypertrophy in certain mammalian species, differing in body mass].

Using cytophotometry and interferometry, ploidy levels and dry weights were determined in cardiac atrium and ventricle myocytes in various mammalian species. Besides, in the same species, using electron microscopy and image analysis, myofibril volume density (MFVD) and mitochondrial volume density (MTVD), as well as the total length of internal mitochondrial membranes (IMM) per cell area unit were measured. The total of 14 mammalian species were studied, with approximately 100,000-fold interspecies differences in the body weight. The dry weights of the left ventricle myocytes in different mammalian species have been shown to vary from 3660 +/- 127 to 8890 +/- 160 pg. Somewhat smaller were the right ventricle myocytes; their dry weight varied from 3598 +/- 134 to 8189 +/- 160 pg. The atrium myocytes were significantly smaller than the ventricle myocytes in all the mammalian species studied. The lowest dry weight of the left atrium myocytes was revealed in the mouse (2415 +/- 96 pg), while the largest weights of the left atrium myocytes were found in the pig (5530 +/- 138 pg). Myocytes of the right atrium, with their mean dry weights in different species varying from 2379 +/- 93 (in the mouse) to 5123 +/- 124 pg (in the pig), were the smallest among all cardiac chamber myocytes. The data obtained indicate that differences in size between the ventricles and atria in mammals are owing predominantly to differences in the number of cardiomyocytes in different parts of the heart rather than to the size of these cells. The dry weight ratio between the right and left ventricle myocytes in various mammalian species was, on average, 0.937 +/- 0.02, and between the right and left atrium myocytes 0.938 +/- 0.04. This ratio between the left atrium and left ventricle myocytes was 0.717 +/- 0.03 and that between the right atrium and right ventricle was 0.722 +/- 0.02. The data obtained indicate that the ratios of cardiomyocyte sizes in different heart parts are rather stable parameters in the mammalian evolution. The mean ploidy levels in myocytes in different parts of the heart corresponded to the mean sizes of the cells. In all the species studied in this work, the ploidy of myocytes of the right ventricle was lower, on average, by 7% compared to myocytes of the left ventricle. The atrial cardiomyocytes had a markedly lower ploidy than the ventricular cardiomyocytes, the myocyte ploidy levels in the left atrium being in all the species higher than in the right atrium. In spite of a higher ploidy level in the ventricular than in the atrial myocytes, this difference in ploidy was less pronounced than the corresponding difference in the myocyte sizes in the same heart parts. In the majority of mammalian species studied, myocyte polyploidization in different parts of the heart combined two ways promoting the increase in the number of genomes in the cells: (1) acytokinetic mitoses in binuclear and multinuclear cells, i. e. mitotic divisions of diploid nuclei without cytoplasm division; in this case no increase in the tissue cell number occurred, (2) alternation of acytokinetic mitoses in mononuclear cells and of bimitoses in binuclear cells; in this case tissue cells increased in number. The ratio of these two ways of polyploid cell formation differed in various species. The former way appeared to be the only in the nutria and horse, whereas the latter way was found in the shrew and arctic fox. In pigs, whose polyploid cardiomyocytes are also formed mainly through the increase in number of diploid cell nuclei, the multinuclear cardiomyocytes contained, apart from diploid nuclei, a small amount of polyploid 4c and 8c nuclei. The formation of such cells is due presumably to the two mechanisms: the asynchronous DNA synthesis in one of the nuclei in a multinuclear cell, and the subsequent incomplete polyploidizing mitosis. (ABSTRACT TRUNCATED)

Animals↗

PubMed1997

[A morphometric study of the silver-stained nucleoli in mononuclear and binuclear rat hepatocytes].

Investigation of silver-stained nucleoli has been made in mono- and binuclear rat hepatocytes of different ploidy. Morphometric parameters of nucleoli and cell ploidy (after silver removing and Feulgen staining) were measured by image analyzer "Videotest". It has been shown that the total area and total volume of nucleoli correlate with cell ploidy, but the found dependence deviates from the proportional one. Possible reasons of such a deviation have been discussed. Marked correlation of total area or total volume of nucleoli was detected between pairs of nuclei of binuclear hepatocytes, whereas between accidental pairs of mononuclear hepatocytes such correlation is practically lacking.

Animals↗