[Modifying effect of low-molecular metabolities on the state of extracellular matrix of connective tissue of animals].

On the basis of complex approach to bone and haematopoetic tissue interaction the authors studied the influence of low weight metabolites on stromal fibroblasts and components of extacellular matrix of bone and skin (collagen and glycosaminoglycans). Specificity of different metabolites action on physico-chemical abilities of type I collagen, amino acid composition changes, surface charge, ratio of alpha- and beta-compounds, BrCN-fragments of alpha-1 component cross-links was shown. The dose dependence of formiate effect on processes of proteins glycosilation, cross-linking in bone and cartilage connective tissue and serum glycoproteins was established.

[Influence of formate on free amino acids contents in tissues and organs of rats in vitro and in vivo].

In experiments in vitro and in vivo influence of formiate on free amino acids contents of tissues and organs of rats has been studied. Results of experiments showed a possibility of amino acids formilation in all investigated tissues. This process could be enzymatic.

[Role of formic acid in transformation of acetic and succinic acids in animal tissues].

Acetic and succinate acids KoA acyl derivatives interacting with formate were displayed to produce alpha-ketoacids--pyruvate and alpha-ketoglutarate. These acids also interact with formate and make pyruvic and malate acids, while alpha-ketoglutarate, evidently, tricarboxy acids. Interaction of formate with acetic and succinate acids inspite of occurring out of the tricarbone cycle increases the latter metabolic functions.

[Cartilage collagen in health and in pathology].

The paper deals with the latest data on structure organization of collagen proteins--basic and minor components of the extracellular matrix of the animal cartilage tissue. Their genetic determination and tissue specificity, differences in the initial structure, sizes of spiral and globular domains, availability of --SH- and --S--S-bonds are emphasized. Data are presented which confirm that the change in the collagen state is one of the determining factors in pathogenesis of the cartilage tissue.

[Collagen from human joint cartilage in deforming arthritis].

Type II collagen of human cartilage has been comparatively studied in norm and at deforming arthrosis. Collagen preparations are characterized by aminoacid composition and electrophoretic mobility in polyacrylamide gel. It is supposed that at deforming arthrosis the degenerative-dystrophic processes in the articular cartilage of man are caused by appearance of procollagen.

[Changes in the structure of postburn keloid scars before and after cryotherapy].

Biochemical and electron microscopy study of the collagen molecule from 14 biopsy specimens of the postburn scar (in 9 patients before and in 5 after cryoeffects) revealed that the postburn scar contains I, II, III and VIII collagen types changed according to the amino acid composition. It was found that after cryogenic effects on the scar there was a tendency to normalization of the collagen structure.

[Structure and properties of collagen in leukemia].

Collagen I was isolated from human bone tissue and from mice bone tissue of the AKR-50 strain at the pronounced stage of leukosis. Dissimilarity of native and leukemic collagens was exhibited after evaluation of their amino acid composition, electrophoretic mobility in polyacrylamide gel containing SDS, content of the carbohydrate moiety as well as of isopoints, elution profiles in reverse-phase chromatography and gel filtration and electron microscopy of SLS-crystallites. Impairments of collagen processing in leukemia appear to be responsible for its alterations in structure and properties.

[Pathogenesis of arthrosis deformans of the knee joint].

The authors have studied the biochemical characteristics (type, aminoacid composition, carbohydrate component content) of the collagene proteins in the articular cartilage in normal conditions and in various expression of deforming arthrosis of the knee joint. The results (collagen of the its type formation, disturbances in the aminoacid composition of collagen of the 1st and 2nd types, changes in the carbohydrate component content, accumulation of procollagen of type 2) allowed to suggest that already at the early stages of development of deforming arthrosis there are distortion of synthesis and disturbance in postsynthetic transformations of the collagen proteins of hyaline cartilaginous tissue which lead to disturbances in the structure and in the function of the matrix and progressive degradation of the articular cartilage.

[Type I collagen in rat skin in an excess of dietary amino acids].

Type I collagen in skin of rats who were given redundant amounts of leucin, valine, methionine or phenyl alanine differed essentially from the normal level in the amino acidic composition. Considerable shifts in the value of pI of the proteins under study as compared with the normal level are found during isofocusing. When studying subunits of collagen preparations by the reverse-phase chromatography certain differences typical of each studied state are revealed in the elution profiles in normalcy and under amino acid loadings.

[Changes in the biosynthesis of acid-soluble collagen in the skin of rats with amino acid imbalances in their diets].

The feeding of excessive leucine and phenylalanine doses to rats against a background of protein deficiency is shown to cause changes in the liver tRNA aminoacylation as well as in the synthesis of acid-soluble skin collagen differing from the normal level in the amino acid composition, elution profiles and content of disulphide groups.

[Effect of tryptophan excess in a diet on amino acid composition of skin collagen and on an initial stage of protein biosynthesis in rat liver].

Protein deficiency and tryptophane load against its background lead to the acid-soluble collagen synthesis in the rat skin. The amino acid composition of the collagen differs from the norm. This is accompanied by changes in the free amino acid pool of blood serum and liver, under tryptophane load the free amino acids pool of the liver increasing twice as high.

[Acid-soluble collagen in the skin of rats who received a tryptophan load and were kept on a protein-free diet].

Crystalline preparations of acid-soluble collagen of rat skin in norm and with tryptophan load against a background of the protein-free diet were fractionated by differential salting out using NaCl in concentrations corresponding to precipitation zones of collagen 1,3 and 4. Amino acid composition, electrophoretic mobility in polyacrylamide gel, profiles of elution from CM-cellulose, content of the carbohydrate component and--S--S-bonds were studied in proteins of the mentioned fractions and in the precipitate insoluble after the pepsin action. Essential differences as compared to the normal level in the amino acid composition and elution profiles were detected in the fraction corresponding to collagen I.

[Crystalline preparations of acid-soluble collagen from rat skin].

Crystalline preparations of rat skin acid-soluble collagen are a complex of collagen and glycoprotein of noncollagenic nature. Heat denaturation of the preparation, treatment with urea and DS-Na result in decomposition of this complex. Proteins composing it differ in amino acid composition, the presence of -S-S-bonds, the amount of a carbohydrate component, electrophoretic mobility in polyacrylamide gel and solubility in acid medium.

[Amino acid composition of preparations acid-soluble skin collagen and free amino acids in rat serum under loading with valine and methionine].

The valine and methionine loading against a background of protein-free diet evokes interrelated changes in amino acid composition of acid-soluble skin collagen preparations and free amino acids pool of blood serum in rats. The isolated collagen preparations also differ essentially from the normal preparations in the content of disulphide groups and elution profiles.

[Molecular heterogeneity of collagen in normal and pathologic states].

Collagen, the main protein of the connective tissue, is characterized by considerable heterogeneity. More than five types of collagen molecules, or seven types of subunits coded by different structural genes are studied. Both in the age aspects and under different pathologies the ratio of collagen types in some tissues changes, new types of collagen molecules are synthetized.

[Biosynthesis of rat skin collagen under amino acid imbalance].

Protein differing from the normal one by the content of S-S-bonds and by the amount of the carbohydrate component was found in the acid-soluble fraction of skin collagen in rats which were fed the protein-free diet and the protein-free diet with the glycine loading for 3 and 14 days and tryptophan for 1, 2 and 3 days. The result testifies to the fact that under extremal states in the animal skin there occurs the synthesis of collagen the structure of which differs from that in the normal animal skin.