[Influence of vitamin E application period on the mineral and D-vitamin metabolism in the organism].

It was shown, that influence of vitamin E on mineral and D-vitamin metabolism depends on its doses and application period: physiological doses of vitamin E activate and large doses - inhibit the effect of vitamin D3 in regulation of mineral metabolism in the organism. The duration of application of large doses of vitamin E (higher than 20 physiological doses) during which the negative changes are not determined has not to exceed 10 days.

[Vitamin D3 transport across the intestines and its metabolism in the liver of rats with alloxan diabetes]. / Transport vitamina D3 cherez kishechnik i ego obmen v pecheni krys pri alloksanovom diabete.

Vitamin D3 intestinal transport and liver metabolism were studied in rats with alloxan-induced diabetes. The condition was induced by i.v. alloxan injection in a dose of 40 mg/kg b.m. Diabetes development was monitored by blood serum glucose measurements, carried out for 30 days. [3H]-cholecalciferol absorption in the rat intestine was found inhibited in the diabetic animals as against the reference animals, which fact results in disordered entry of vitamin D3 to the body. [3H]-cholecalciferol absorption by the liver is reduced in the examined condition, and the time of its metabolism is increased more than threefold as against the reference animals. The share of vitamin D3 hydroxylation by the liver of diabetic rats is also significantly reduced. The described disorders are responsible, among other things, for the reduction of the levels of vitamin D3 active metabolites in the blood serum of rats with experimental diabetes.

[Cardiac bioelectrical activity in healthy men during 370-day head-down tilt hypokinesia]. / Bioélektricheskaia aktivnost' serdtsa zdorovykh muzhchin v usloviiakh 370-sutochnoi antiortostaticheskoi gipokinezii.

Nine men, aged 27-42 yrs, have been examined during a 370-day head-down tilt (HDT) experiment. The group A test subjects (4 persons) used the countermeasures involving exercises, pharmacological means to correct metabolism, bone tissue and digestive function. The group B test subjects (5 individuals) have embarked on exercising only in 120 days of bedrest. The electrocardiographic changes in the group A test subjects were insignificant, manifested mainly as a moderately decreased T-wave amplitudes in the most leads. In the group B test subjects at early HDT stages there was a negative dynamics: an elevated heart rate (HR) at rest, an increased time of atrioventricular transmission, decreased T-wave amplitudes followed in some cases by its widening and deformations. After the onset of physical training there appeared a tendency toward normalizing the values although T-wave amplitudes till terminating a bedrest period never reached baseline levels. In a rehabilitation period, both groups displayed the dynamics similarity: initially the HR lability and certain decrease in T-wave amplitudes were noted. By the end of 2nd month of rehabilitation the ECGs in all the test subjects of both groups practically normalized, but in Group B this process developed more slower. Thus, a year-long HDT experiment exerted a moderately adverse effect on myocardium metabolism and HR control mainly in the Group B test subjects. The observed changes are reversible and can be regarded as functional.

[Metabolism of vitamin D3 administered in liposomes in rat liver]. / Metabolizm vitamina D3, vvedennogo v liposomakh, v pecheni krys.

Incorporation of [3H]-cholecalciferol into the liver and the rate of its conversion into 25-OH-D are significantly larger after intravenous administration of this vitamin into liposomes than its dissolution in ethanol. The latter may be due to a different distribution of vitamin D3 in the cells of the liver. Incorporation of [3H]-vitamin D3 in reticulocytes suggests that its cells are a locus for storage of vitamin D, from which the latter is transported into hepatocytes where its 25-hydroxylation proceeds.

[Radiation-induced changes in the content of squalene, lathosterol and cholesterol in rat blood proteins]. / O radiatsionnykh izmeneniiakh soderzhaniia skvalena, latosterina i kholesterina v belkakh plazmy krovi krys.

Normal and irradiated fibrinogen, gamma-globulins, alpha- and beta-globulins and albumins of blood plasma were shown to contain squalene, lathosterol, cholesterol and some other compounds as lipid components. Radiation alteration of the total number of unsaponifiable substances and some lipid components in the individual blood plasma proteins followed certain regularities depending on the kind of a protein. The level of radiation changes in the content of lipid components in specific proteins of blood plasma was shown to be a function of radiation dose and time after irradiation.

[Effect of varying vitamin D status in the body on intestinal absorption and metabolism of vitamin D in the rat liver]. / Vliianie razlichnoi obespechennosti organizma vitaminom D na ego vsasyvanie v kishechnike i metabolizm v pecheni krys.

The absorption of [3H]-vitamin D3 in the intestine and its hydroxylation in the liver were higher in vitamin D-deficient rats than in vitamin D-treated ones. The higher is the vitamin content in the organism, the greater part of the label is occupied by unchanged vitamin D3. It is supposed that both absorption of the vitamin in the intestine and its 25-hydroxylation in hepatocytes may decrease with a rise of the vitamin D3 amount. This activates a mechanism of protection from the vitamin D redundancy.

[Structural-functional changes in plasma lipoproteins during vitamin D-deficient rickets in children]. / Strukturno-funktsional'nye izmeneniia lipoproteinov plazmy krovi pri vitamin-D-defitsitnom rakhite u detei.

The lipid composition and structure of low- and high-density lipoproteins (LDL and HDL) have been studied in children with the vitamin D-deficient rachitis. An increase of the cholesterol content in the atherogenic LDL against a background of its decrease in the antiatherogenic HDL has been revealed, that is analogous to the observed changes under the atherosclerosis development in adults. Due to the studies in the amino acidic composition and determination of the nature and quantity of the charged groups of lipoprotein particles accessible for titration definite, certain disturbance in the structure of lipoproteins are observed as such that may cause disturbances in their functional activity.

[Structural properties and lipid-binding characteristics of plasma fibrinogen and gamma-globulins in vitamin D-deficient rickets]. / Strukturnye osobennosti i lipidsviazyvaiushchaia sposobnost' fibrinogena i gamma-globulinov plazmy krovi pri vitamin-D-defitsitnom rakhite.

Structure properties and lipid-binding ability of fibrinogen and gamma-globulins were studied in blood plasma of children with rickets. Content of cholesterol and its esters, developing complexes with fibrinogen, was found to increase simultaneously with a decrease in the phospholipids, containing in the protein fraction, under conditions of the disease. Surface charge of the proteins studied, especially of fibrinogen, was altered, thus demonstrating the distinct impairments of their structure and functions. Lipid environment appears to be of importance in functional activity of these proteins.

[Phospholipids bound with plasma proteins in children with vitamin D-deficient rickets]. / Fosfolipidy, sviazannye s belkami plazmy krovi detei, bol'nykh vitamin-D-defitsitnym rakhitom.

Composition of phospholipids bound with plasma proteins in the healthy children and in those with vitamin-D-deficient rickets are studied. It is found that the quantitative and qualitative content of phospholipids in the low- and high-density lipoproteins increases considerably with the rickets. At the same time the content of phospholipids which form complexes wit fibrinogen gets two times lower. The character of changes in the phospholipid composition in protein fractions and in the whole plasma in case of rickets is different.

[Content of squalene and sterols in tissues of the hemopoietic system in normal rats and in experimental leukemia]. / Soderzhanie skvalena i sterinov v tkaniakh krovetvornoi sistemy krys v norme i pri éksperimental'nom leikoze.

Contents of scvalene, sterols and their derivatives were studied in lymphoid tissues as well as in liver and kidney tissues of normal rats and the animals with Shvetz experimental leukosis. Amount of cholesterol and of its precursor scvalene was distinctly decreased simultaneously with an increase in total content of nonsaponified substances in thymus, spleen, bone marrow and liver tissue of rats with experimental leukosis. Scvalene was increased in kidney tissue. Simultaneous accumulation of hydroxycholesterol derivatives, among which 7-beta-hydroxycholesterol was identified, was observed in these tissues under conditions of leukosis. Role of cholesterol hydroxyderivatives in biosynthesis of sterols is discussed.