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Biomedical subjects

B V Rubtsov

Publications and source records attributed to B V Rubtsov.

10 recordsLinked to original sources
PubMed1980

[Effect of thyroxine on the function of rabbit skeletal muscle sarcoplasmic reticulum].

Thyrotoxicosis in rabbits was induced by prolonged intraperitoneal injection of L-thyroxin. The development of thyroxicosis was assoiated with a decreased Ca2+ accumulation rate by sarcoplasmic reticulum (SR) fragments and a lowered Ca2+ dependent ATPase activity. As compared to the analogous parameters in normal animals. Ca2+ accumulation rate and ATPase activity of thyrotoxicosis animals decreased by 60 and 25%, respectively. The changes in the specific parameters of SR were also observed during incubation of normal SR samples in the medium containing thyroxin (10-5 M). The changes seen in SR functioning in thyrotoxicosis animals are likely to be related to structural rearrangements of lipoprotein surroundings of Ca-ATPase.

Animals↗
PubMedDate not supplied

[Effect of valinomycin on structural and functional transitions in sarcoplasmic reticulum membranes].

Effect of valinomycin (VAL) on ATPase activity and transport of calcium ions in sarcoplasmic reticulum (SR) vesicles has been studied, as well as the diffusion efflux of calcium ions from liposomes of the total fraction of SR lipids. The studies were carried out in the temperature range of 10 divided by 50 degrees. Changes in the structure of SR membranes were checked with a fluorescent probe of 3-metoxibenzantron. It was shown that at the molar ratios 1:7000-1:70 VAL decreases its ATPase activity and active transport of calcium ions in SR at all temperatures. Besides VAL decreases the rapid efflux of calcium ions from SR and the diffusion efflux of calcium ions from liposomes within the temperature range 10 degrees divided by 35 degrees; it increases the rates of these processes at higher temperatures. Simultaneously the broadening of temperature intervals of structural transitions in the SR membranes takes place.

Adenosine Triphosphatases↗
PubMedDate not supplied

[Temperature-dependent functional changes in sarcoplasmic reticulum membranes].

Temperature effect on changes in calcium ion transport and activity of Ca-ATPase of sarcoplasmic reticulum vesicles (SRV) was studied. Several temperature intervals of the change of SRV functional activity parameters were found: 8-12 degrees C-beginning of accumulation of SRV Ca2+, 12-19 degrees sharp activation of Ca2+ accumulation, 27-32 degrees-activation of passive yield, 36-43 degrees-reversible change of the activity of the accumulation system and activation of Ca yield, 48 degrees and higher--irreversible denaturation of transport Ca-ATPase. Coincidence of temperature intervals of SRV structural reconstructions, detected by means of fluorescent probes and functional changes points to a close relationship between structural reconstructions and functional responses of biological membranes.

Animals↗
PubMedDate not supplied

[Transmembrane potentials at the cell membrane and mitochondrial membranes of rat thymocytes at the early stage of developing a stress reaction using potential-sensitive fluorescent probes].

4-(p-dimethylaminostyryl)-1-methylpyridinium (DSM) and 3,3-dipropyl-2,2'-thiodicarbocyanin(diS-C3-(5] were used in the investigation of cytoplasmic and mitochondrial transmembrane potentials at an early stage of the stress reaction of rats. It was shown that 60 minutes after the beginning of the stress action the mitochondrial transmembrane potential was substantially decreased. The transmembrane potential of the cytoplasmic membrane did not change. It may be deduced from the obtained data that the morphological changes of the thymus induced by the strong stress impact are preceded by a change of the mitochondria functional state manifesting itself by a decrease of the mitochondrial membrane potential.

Animals↗
PubMedDate not supplied

[Effect of valinomycin on the phase state and passive permeability for calcium ions of membranes from artificial phospholipids].

Effect of valinomycin on passive permeability for calcium ions of liposomes from artificial phospholipids of dimiristoillecithin and dipalmitoillecithin under the conditions of thermotropic structural transitions which were controlled by means of fluorescent probe of 3-metoxibenzantron. It was found that the incorporating of valinomycin into the membrane depends on the density of phospholipid packing. The change of the physical state of phospholipids under the effect of antibiotic was correlated with the change of passive permeability of liposomes for calcium ions.

Calcium↗
PubMedDate not supplied

Effect of triterpene glycosides of marine invertebrates on permeability of biological and artificial membranes.

The influence of the triterpene glycosides holothurin and cucumariaside from Holothuria grissi and Cucumaria japonica, respectively, on the parameters of the active transport of calcium ions by vesicles of the sarcoplasmic reticulum and on the permeability of liposomes formed from the total fraction of egg phospholipids was investigated. It was found that at low concentrations these substances decrease the Ca-ATPase activity without noticeably increasing the permeability of the membranes, whereas at high concentrations they cause a sharp increase in the permeability of the membranes of Ca2+ ions.

Animals↗