PubMed Health⌕ Search

Biomedical subjects

R A Kotel'nikova

Publications and source records attributed to R A Kotel'nikova.

8 recordsLinked to original sources
PubMed1997

[Inhibitory effect of the radiosensitizer AK-2123 on experimental liver metastasis and active transport of calcium ions].

Radiosensitizer AK-2123, a triazol, has been shown to significantly inhibit the development of hepatic metastases induced in syngeneic mice by intrasplenic injections with cels of bowel adenocarcinoma. The antimetastatic effect was produced by use of a very low dose of the drug. A therapeutic dose of AK-2123 has been shown to inhibit active transport of calcium ions across sarcoplasmic reticular cells effected by Ca(2+)-dependent Mg(2+)-activated ATPase. It is suggested that the antimetastatic effect of AK-2123 is determined by at least partial inhibition of active transport of calcium.

Adenocarcinoma↗
PubMedDate not supplied

[Structural-functional changes in biomembranes during complications of diabetes mellitus and their pharmacological correction].

The decrease of sorbitol dehyidrogenase activity and the increase both of aldoso reductase activity and sorbitol concentration in aorta or eye lens under experimental diabetic angiopathy have been shown. The structural and functional alterations in erythrocytes membranes under angiopathy studied by spin- and luminesoense probes confirm the hypothesis on the major role of membrane pathology processes in the pathogenesis of diabetic mellitus. Pharmacological correction of diabetic angiopathy by glucophag or new antioxidant LBK-78 normalized the studied diversions on the membranes level.

Animals↗
PubMedDate not supplied

[Study of sarcoplasmic reticulum Ca-ATPase by the paramagnetic label--paramagnetic probe method].

ESR spectra of nitroxyl derivative labelling with parachlormercury benzoate bound with SH-groups of Ca, Mg-dependent ATPase in the presence of Mn2+ ions are studied. It has been concluded from the saturation curves of ESR spectra that Mn2+ is localized at the distance approximately 40 A from the SH-group of the enzyme active centre. Platinum compound (K2PtCl4) changes the spectrum of ESR 1 due to the displacement of the label from the enzyme SH-groups and disintegration of the sarcoplasmic reticulum structure. Palladium compound (Pd(NH3)4Cl2) produced no effect on the ESR 1 spectrum.

Animals↗
PubMedDate not supplied

[Localization of tryptophan residues in Ca2+-ATPase from sarcoplasmic reticulum].

By the methods of spectroscopy, fluorimetry and chemical modification of tryptophane residues with N-bromsuccinimide, the sarcoplasmic reticulum of rabbit sceletal muscle was shown to contain 18 +/- 1 tryptophane residues per Ca2+-ATPase molecule, 6 of which were, probably, inside the protein globule, in its hydrophobic region, and thus unavailable for modifier, while the rest 12 +/- 1 were easily transformed to the 6-oxyindole chromophore being the main source of the intrinsic fluorescence of the enzyme. The quantum yield for the rest four residues was equal to 0.015. Four tryptophane residues are located at the distance of less than 14 A from the ATP-binding site of the enzyme. The quantum yields of fluorescence for 8 of the tryptophane residues of Ca2+-ATPase were similar and equal to 0.03.

Animals↗
PubMedDate not supplied

[Spectrofluorometric topography of the ATPase center of Ca2+-Mg2+-dependent ATPase of sarcoplasmic reticulum by means of platinum and palladium compounds].

The fluorescence of tryptophan residues in Ca2+--Mg2+-ATPase was studied in the presence of K2PtCl4, K2PdCl4 and 5-sulpho-8-mercaptochinolinate platinum and palladium. It has been shown that both first two compounds quenched the fluorescence dye to bonding with SH-groups in ATPase active centre, but the last two compounds influence the fluorescence by bonding with tryptophan residues. The distance between the SH-groups and tryptophan in the active centre was determined by Foerster--Galanin equation and was equal to 14 +/- 3 A.

Animals↗
PubMedDate not supplied

[Study of catalytically active center of the Ca2+-Mg2+-dependent ATPase of sarcoplasmic reticulum by triplet probe method].

It was shown that eosine and erythrosine are competing inhibitors of the Ca2+-Mg2+- dependent ATPase active center of sarcoplasmic reticulum. The eosine and erythrosine inhibition constants are equal to 1.4 x 10(-6) M and 1.1 x 10(-6) M, respectively. Nitroxide radicals of various hydrophobicity and K3Fe(CN)6 were used to compare the constants of triplet states exchange quenching of erythrosine in aqueous solution, in lecithine liposomes and in ATPase active center of sarcoplasmic reticulum. It was established that ATPase binding center was immersed into a liquid phase and was not connected with lipids. Mn2+ and Gd3+-ions, which are competing with Mg2+ and Ca2+ for binding sites in the enzyme active center, diminished the phosphorescence quenching time of eosine at 77K. This means that the ion binding sites are less than 12 A apart from ATP-binding center.

Animals↗
PubMedDate not supplied

[The use of the annihilated delayed fluorescence phenomenon in the study of the structural organization of the sarcoplasmic reticulum].

Self-interaction of triplet-excited probes and interaction between the triplet-excited probes and a quencher (ferrocene) at 30 degrees C have been studied in Sarcoplasmic reticulum membranes (SR) and in dimiristoyl phosphatidylcholine liposomes by means of annihilated delayed fluorescence (ADF) registration. Perylene, 7,12-dimethyl benzanthracene and 4-(2-anthryl) butanoic acid have been used as triplet probes. An average time decay ADF of perylene and 4-(2-anthryl) butanoic acid in SR is equal to 4,2: 10(-5) s and 2,3 X 10(-5) s, respectively. Triplet states constant quenching of perylene by ferrocene is equal to 2,1 X 10(7) (mM/g of lipids)-1 X s-1 in SR and 4,5 X 10(7) (mM/g of lipids)-1 X s-1 in liposomes. This means that lipids in a liquid crystalline phase form continuous extended regions containing more than 7 X 10(3) lipid molecules and free of significant hindrances in probes diffusion.

Chemical Phenomena↗