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N V Samosudova

Publications and source records attributed to N V Samosudova.

At least 37 records · Page 2Linked to original sources
PubMed1979

[Interrelationship between the striated structure of muscle and the distribution of calcium in it. I. The changes in the protofibrillary structure of the frog fast muscle fibers in steady potassium contracture].

The ultrastructure of protofibrillar apparatus of frog fast fibers was studied during a prolonged contracture initiated with KSCN. SCN anion inhibited Ca-pump, which resulted in maintaining a high intracellular Ca2+-concentration. It was suggested that stable connections between action and myosin filaments were formed within the region of overlapping. Under these conditions, thick and thin filaments were able to change their length from 1.3 to 1.9 micrometer, and from 0.83 to 1.2 micrometer, correspondingly, according to the sarcomere length. The structural non-uniformity of I-band was observed in contracted sarcomeres: a low electron density zone 30--40 nm wide was formed at the I/A band boundary.

Animals↗
PubMedDate not supplied

[Ultrastructure of frog muscle fiber thick filaments at rest and during potassium contracture].

Isolated slow and intermediate frog muscle fibres were fixed in the rest state and under potassium contracture (50-100 mM KC1). The longitudinal and cross sections of two types of fibres were investigated. It was shown that at the rest the thick filaments of different fibres had similar length (1.6-1.65 mum), diameter (160-165 A) and the amount of subunits (12-13). Under potassium contracture the length of the thick filaments of both fibre types was shortened by 25-30% of the rest-length, the diameter of the slow fibres increased to 180-185 A, the diameter of the intermediate fibres to 200-220 A. The amount of subunits increased to 14-15 in slow fibres and to 17-18 in intermediate fibres. We believe that the ultrastructural changes observed in the thick filaments are a result of molecular transformation in these filaments, which seems to be important for maintaining the contracture.

Animals↗
PubMedDate not supplied

[Complex biochemical and structural study of skeletal muscles in scoliosis].

Structural study of human scoliosis muscles showed significant dystrophic and degenerative changes: desintegration of fibrillar structure and striation; the Zencker necrosis; the replacement of muscular tissue by connective and adipose tissues. The electron microscopic observation revealed disordering of filamental array of the sarcomere (I- and A-discs), the broadening of Z-disc material, the appearance of N-stripes in I-band. At the same time deviations from the norm were observed in contractile proteins: actin and myosin. ATPase activity of myosin decreased by 25--30%; the flow of birefringence of myosin and especially of actin also decreased. Actin from the scoliosis muscles partially or completely lost the ability for polymerization in 0.1 M KC1.

Actins↗
PubMedDate not supplied

[A possible physico-chemical mechanism of cell fusion in skeletal muscle myogenesis by means of intercellular pinocytosis].

The fusion mechanism of cells in myogenesis of skeletal muscle is proposed on the basis of capacity of forming intercellular contacts with pentalamellar structure to invaginate up to the formation of free vesicles, i.e. the intercellular pinocytosis. This process leads to a "loss" of the membrane material with the following perforation and rupture of the membrane at the site of cell contact. The formation of invaginations is connected with the clusterization of proteins on the cytoplasmic surface of plasmalemma, accompanied by an alteration of Gibbs' surface energy with the appearance of chemically induced and bending moments. The transition from the invagination to the vesicle depending on osmotic gradient of pressure between the fusing cells was estimated quantitatively. This gradient is determined by the mechanism of polymerization of protein subunits during the assembly of contractile elements in one of fusing cells.

Animals↗
PubMedDate not supplied

[Localization of adenine components in chick myofibrils by the ferritin antibody technic].

The immunochemical method has been proposed to indicate the adenin compounds in isolated myofibrils of striated muscle. Adenosine--containing antigen was prepared by coupling adenosine with bovine serum albumin (adenosine--BSA). Antibodies against adenosine--BSA were labelled by ferritin. The sites of the antigen antibody reaction were marked by localization of ferritin molecules. Ferritin antibodies were found to concentrate in the following sarcomere sites: M and Z bands, N-lines and terminal cisternae of sarcoplasmic reticulum near the Z-bands.

Adenine↗