Effect of the genotype on the serotonin and 5-hydroxyindoleacetic acid content in different sections of the mouse brain

The levels of serotonin and 5-hydroxyindoleacetic acid contents were estimated in hypothalamus, hyppocampus and midbrain of inbred mice of 12 strains. The levels of serotonin and its metabolite in various parts of brain representing different links of its serotoninergic system were shown to be genetically determined. The correlation analysis revealed that there were two, relatively autonomous genetic systems controlling biosynthesis and catabolism of serotonin in brain.     

Directed and spontaneous disulfide bond closure using hydrogen peroxide in the synthesis of endothelins-1 and -3]

The linear precursors of endothelin 1 and endothelin 3, natural vasoactive peptides, were obtained by using the Boc- and Fmoc-schemes of solid phase peptide synthesis. The methods of directed and spontaneous formation of two disulfide bonds in the molecules of these precursors were compared and shown to give comparable results. The conditions were found that provided the selective S-S-ring closure in the methionine-containing endothelin 1 by means of hydrogen peroxide without the undesired conversion of the Met residue into the corresponding sulfoxide.     

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.     

The ligand-dependent phosphorylation of epidermal growth factor receptors and the production of a secreted form of the receptor by cell strains of A-431 epidermoid carcinoma

Primary reactions on the addition of the epidermal growth factor (EGF) were investigated for the strains of A-431 cells, resistant to the antiproliferative effect of EGF. In spite of differences of EGF reception in the obtained strains, the EGF receptors in membrane preparations of these strains maintain the phosphorylating ability after addition of EGF. The rate of internalization of 125I-EGF in normal and resistant cells is the same. The production of a secreted fragment of the EGF receptor in resistant cells is lower than in normal ones. Questions of regulation of production of the normal receptor and of its shortened secreted fragment are discussed.     

Effect of prolonged interaction of mice with aggressive and submissive types of behavior on the concentration of serotonin, 5-hydroxyindoleacetic acid and noradrenalin in the brain

As a result of repeated experience of victories and defeats in mice of C57BL/6 line, submissive and aggressive types of behaviour were elaborated, the stabilization of which was accompanied by a change in serotonin and noradrenaline content in various parts of the brain, at least of two kinds. Nonspecific unindirected changes in transmitter' levels found in both groups of animals in comparison with the control, are apparently due to the experience of zoosocial contracts. Changes were also noted connected with specificity of the observed behaviour.     

Cytofluorimetric research on the content of glycogen and its fractions in the hepatocytes of patients with liver cirrhosis of different etiologies]

By cytofluorometric method, a study was made of the total glycogen and its two fractions in liver parenchymal cells both in the donors (20 men) and in patients with cirrhosis of different etiology (39 men). The examination was performed on preparations--smears of isolated hepatocytes, obtained from the live functional liver biopsies. The quantitative analysis has shown an increase in the total glycogen content in hepatocytes of patients with cirrhosis by 3 times compared to the norm, and this increase is independent on the etiology of liver cirrhosis. To study the mechanism of the discovered glycogenosis, the activity of key enzymes of glycogenolyses was determined. It was shown that glucose-6-phosphatase and glycogen-phosphorylase activity in the liver with cirrhosis was lower than in the norm. The most considerable changes were shown in hepatocytes of patients with liver cirrhosis in fractional glycogen composition and, even more significant, in the content of a hard soluble fraction. The hard soluble fraction portion was higher in hepatocytes of the patients with liver cirrhosis of alcohol etiology. The quantitative analysis of glycogen fraction contents in liver cells may be the best marker in the differential diagnosis of symptomless elapsing liver cirrhosis.