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V O Shpikiter

Publications and source records attributed to V O Shpikiter.

15 recordsLinked to original sources
PubMed1986

[Effect of the proteolysis of low-density serum lipoproteins on their interaction with macrophages].

125I-labelled human serum low density lipoproteins (LDL) were incubated with cultured mouse peritoneal macrophages at 37 degrees C, with the following study of cellular uptake and 125I-LDL degradation by measuring the content of TCA-soluble products of LDL hydrolysis in the cultural medium. It was shown that limited pepsin proteolysis of LDL (10%) led to a more effective LDL uptake and degradation by macrophages. The data suggest that enzyme-induced modification of LDL may increase their atherogenicity.

Animals↗
PubMed1981

[Effect of heparin on serum low density lipoproteins].

The effects of heparin on human serum low density lipoproteins (LDL) were studied by analytical ultracentrifugation. Precipitation of LDL without considerable alteration of the LDL micelles remaining in the solution was observed after addition of 1-10 micrograms of heparin to the samples containing 5 mg of LDL in 1 ml of 0.01 M Tris-buffer, pH 7.4, and 0.05% Na2-EDTA. The interaction between LDL and heparin was of electrostatic nature, i. e. it was inhibited by NaCl. The increase in the amount of the heparin added (up to hundreds micrograms) was accompanied by solubilization of the LDL precipitates; in the presence of certain concentrations of heparin the associates of LDL (apparently dimers) were formed. An addition of 1 mg of heparin to the samples containing 5 mg of LDL in 1 ml of the above buffer was accompanied by binding with the LDL of approximately 40 micrograms of heparin (data calculated from changes in the sedimentation co-efficients).

Heparin↗
PubMed1977

[Action of lipases on low-density serum lipoproteins].

It was shown that the action of phospholipase A2 on low density serum lipoproteins (LDL) in the presence of serum albumin led to decrease in the floatation coefficient. Lipase hydrolyzed LDL triglycerides after pretreatment of the latter with phospholipase A2. Due to the action of lipases the LDL residue loses its solubility and the cholesterol-rich precipitate forms. The loss of solubility of lipoproteins treated with lipases and proteinases may occur in vivo, underlying athermao formation, i.e. can thus serve as one of the factors in the pathogenesis of atherosclerosis.

Chemical Phenomena↗
PubMedDate not supplied

[The role of lipoprotein modification in atherogenesis (review)].

Structural stability and interaction of modified blood serum lipoproteins with cells and the components of intercellular matrix are reviewed. Modified lipoproteins might possess more distinct atherogenic properties as compared with the native lipoproteins. Existence of modified lipoproteins in vivo is considered.

Arteriosclerosis↗
PubMedDate not supplied

[Action of aortic cathepsin D on serum low-density lipoproteins].

Action of aortic cathepsin D on low density lipoproteins /LDL/ from human serum was studied by means of analytical ultracentrifugation. Cathepsin D intensively hydrolysed LDL, leading to decrease in the sedimentation coefficients of the product formed. The product of degradation of LDL possessing a sedimentation coefficient of 4.5 S /in 0,04 M KBr; 0,042 M NaCl, 2 mM EDTA, 6 mM Tris, pH 7.3 /contained apparently the minimal amount of proteins, which could still maintain the stability of partially hydrolysed LDL. When the degree of hydrolysis reached 40%, a heterogenous mixure, containing the flotating and slowly sedimenting products, was formed. These products gradually lost their solubility. The data obtained suggest that the insoluble products of the proteolysis may be formed in aortic wall some disorders of the lipoprotein metabolism.

Animals↗