An assessment of the relative contribution of the processes of cellular proliferation, polyploidization and hypertrophy to the increase in liver mass at various stages in the postnatal development of rats

Changes in isolated hepatocyte dry mass, its ploidy and liver mass at different stages of the rat postnatal ontogeny were investigated. The determination of these processes and special calculation made it possible to estimate quantitatively a relative contribution of cell proliferation, polyploidization and hypertrophy, not associated with DNA synthesis to the increase in the liver mass at different stages of the rat development. During the first week after the rat's birth, its liver growth is provided by 61 and 39% with hepatocyte proliferation and hypertrophy, respectively. Between the 14th and the 21st days of development, when considerable functional changes occur in the rat liver, the contributions of proliferative and polyploidization processes, and of cell hypertrophy into the liver mass increasing are roughly identical. Later on, the contribution of cell hypertrophy into the liver growth is noticeably reducing to reach within 1-2 months only 1%. On this developmental stage the liver mass increment by 2/3 is provided due to cell proliferation and by 1/3--to its polyploidization. As a whole, the accelerated growth of the rat liver from the birth to sex puberty is described as follows: the contribution of processes of proliferation and polyploidization, and of cell hypertrophy correspond to 28, 30 and 42%, respectively; afterwards, the liver growth being retarded. Within the period from 2 to 6 months, the liver mass increase is provided mainly (up to 76%) by cell proliferation, the shares of polyploidization and cell hypertrophy being 8 and 16%, respectively.     

Interaction between proteinases secreted by the fungal plant pathogen Rhizoctonia solani and natural proteinase inhibitors produced by plants

The fungal plant pathogen Rhizoctonia solani Kuhn. grown in a medium containing thermostable potato tuber proteins produced proteinases active at moderately alkaline pH values. Electrophoretic analysis in polyacrylamide gel with SDS and copolymerized gelatin showed that the extracellular proteinase complex contained four components that differed in molecular weight. Studies on the action of the exoenzymes on various synthetic substrates indicated that the culture liquid of R. solani contained mainly trypsin-like proteinases. The exoproteinase activity was virtually completely suppressed by trypsin inhibitor proteins isolated from potato tubers and seeds of various legume species. The results suggest that the extracellular proteinases produced by R. solani play a significant role in attacking plant tissue, and natural inhibitors contribute to the protection of Solanaceae and Leguminosae from this fungal pathogen.     

The characteristics of the manifestation of hereditarily induced anxiety in male C57Bl/6J and CBA/Lac mice

Behavior of male mice of C57Bl/6J and CBA/Lac strains was tested in the elevated plus-maze and open field in order to estimate state anxiety in novel conditions. The cube and partition tests were used to reveal trait anxiety in the familiar conditions of the home cage. It is concluded that genetically defined state anxiety is more pronounced in CBA/Lac mice and trait anxiety in C57Bl/6J strain.     

The study of exploratory behavior in CBA/Lac male mice under influence of positive and negative social interactions

The exploratory activity towards a new object placed in the home cage was studied in CBA/Lac male mice after their repeated daily social victories and defeats. After 10 daily social defeats, submissive mice displayed a significantly declined exploration of a new object, whereas aggressive mice with experience of 10 daily victories expressed only a mild decrease in exploratory activity (as compared to control). Twenty daily social defeats almost completely abolished exploratory behavior in submissive mice, whereas 20 daily victories resulted in the increased exploration of a new object in aggressive mice. It is suggested that repeated social defeats associated with the negative psychoemotional state lead to the development of a pronounced exploratory motivational deficit. On the other hand, the experience of repeated daily aggression forms the enhanced motivational excitement that prevents a relevant response to a neutral stimulus.     

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.     

Influence of experimental context on the development of anhedonia in male mice exposed to chronic social stress

Consumption of 1% sucrose solution supplemented with 0.2% vanillin was studied in two experimental contexts in male mice living under chronic social stress induced by daily experience of defeats in agonistic interactions and leading to development of depression. In the first experiment, vanillin sucrose solution was made available as an option along with water during 10 days for mice living in group home cages. Then the mice were subjected to repeated social defeat stress and during exposure to stress they were provided with both vanillin sucrose solution and water using a free two-bottle choice paradigm. In the other experiment, vanillin sucrose solution was first offered to mice after 8 days of exposure to social defeat stress. Males familiar with vanillin sucrose solution showed vanillin sucrose preference while experiencing defeat stress: consumption of vanillin sucrose solution was about 70% of total liquid consumption. However, the consumption of vanillin sucrose solution per gram of body weight in mice exposed to social stress during 20 days was significantly lower than in control males. In the second experiment, males after 8 days of social defeat stress were found to consume significantly less vanillin sucrose solution as compared to control males. On average, during two weeks of measurements, vanillin sucrose solution intake was less than 20% of total liquid consumption in males. Consumption per gram of body weight also appeared to be significantly lower than in control group. The influence of experimental context on the development of anhedonia measured as a reduction of sucrose solution intake by chronically stressed male mice is discussed.     

Spectral and photometric characteristics of different batches of auramine O (OO)]

The spectra of absorption and fluorescence of Auramine O (OO) specimens in water solution and in cells, stained with Schiff-type auramine-SO2 reagents for DNA, were investigated. Using different specimens of the stain the accuracy and sensitivity of the cytofluorometric method were estimated by the next parameters: the value of the useful signal from the nucleus (no), the value of the production of no by the time constant of fading (tau), the value of proportion of the signal to the background (no/nphi) and, in addition, the value of the variation coefficient under the measurement of the rat liver tetraploid cells. The purity of the dye was shown to interfere largely with accuracy and sensitivity of the above method. Auramine 00 of the Reanal production appeared to have the best photometricl characteristics. For this, the maxima of the absorption spectrum in the 320--700 nm region in the solution and in the cell were 371 and 433 nm, and 375 and 436 nm, resp. The maximum of the fluorescence spectrum was found 521 nm and 526 nm, resp. for the solution (0.02%) and for the Auramine-SO2 treated cells. Moreover, an isomer of Auramine O (00) -- Auramine G can be used for detection and photometrical measurement of DNA and glycogen after the Feulgen and PAS reactions, resp.     

Response of the serotoninergic brain system to social stress of various duration in male mice C57BL/6J and CBA/Lac]

The effects of social stress caused by experience of defeats in mice during 3 or 10 consecutive days of intermale confrontations on serotonergic brain activity (5-HT, 5-HIAA levels and 5-HIAA/5-HT ratio) in some brain regions of CBA/Lac (CBA) and C57BL/6J (C57) inbred mice have been studied. It was revealed the significant changes in 5-HT methabolism in the brain regions of defeated mice (losers) of CBA strain after 3 intermale confrontations. However, after 10 days of social stress these changes (excluded amygdala) turned to the control measures testifying to the adaptive mechanisms of serotonergic system in CBA losers. In C57 strain, the three-day social stress produced the mild changes in the brain serotonergic activity both quantitatively as well as qualitatively. Nevertheless, losers subjected to ten-day intermale confrontations had more expressed changes in 5-HT, 5-HIAA levels of 5-HIAA/5-HT ratios in the brain regions studied. It seems that long lasting social stress induced the development of disbalance of the brain serotonergic activity in C57 losers: it was shown the hyperactivity in the hypothalamus and hypoactivity in the amygdala and nucl. accumbens. Apparently, this cause leads to the development of the pronounced anxiety shown earlier in this mouse strain.     

Cytostatic effects of bifolar and chlofiden. Effect on protein synthesis and cell cycle

Study of influence of new antitumor preparations bifolar and chlofiden on rat liver protein biosynthesis in vivo and on sarcoma-45 in vitro was carried out using labeled precursor 3H-leucine. It was shown that the preparations inhibited protein synthesis in normal and malignant tissues. Mitotic cycle and its phases were investigated with 3H-tymedin. It was established that bifolar influenced all the phases of mitotic cycle and the sensitive phases of the mitosis itself, which are connected with the redistribution of genetic material.     

Microecology and humoral immunity characteristics of the vagina in women with nonspecific inflammatory diseases of the genitals

The complex cytological, microbiological and immunological examination of 90 female patients with nonspecific inflammatory diseases of the genital tracts and 30 clinically healthy women (the control group) was carried out. The examination revealed significant microbiocenosis changes in the lumen and the parietal area of the vagina, depending on the severity of the infectious process: a decrease in the level of lactobacilli, an increase in the content of opportunistic facultative anaerobic microorganism in the lumen and obligate anaerobic bacteria in the parietal area. Pronounced correlation between the content of opportunistic microorganisms and the levels of IgM and IgA, as well as secretory IgA and free secretory component in vaginal secretions in patients in patients with non-specific inflammatory diseases of the genital tracts has been revealed.