[Effects of sterols having different chemical structure and squalene on osmotic resistance of erythrocytes].

The effects of sterols having different chemical structure and squalene on osmotic resistance of erythrocytes were studied. Changes in sterol and squalene content in the membranes were induced by incubation of erythrocytes with liposomes containing the additive. A decrease of the osmotic resistance of erythrocytes was shown to correlate with a cholesterol decrease in the membranes.

[Disturbanes in electrostatic balance of erythrocyte membranes in experimental D-hypovitaminosis].

Violation of electrostatic balance in the erythrocyte membranes with experimental D-hypovitaminosis is determined by the method of potentiometric titration. It is pronounced in modification of quantity and pK of accessible polar groups and in a decrease in total membrane electronegative charge. This violation is supposed to be provoked by a considerable increase in cholesterol content in the membranes and to reflect a modification in the character and bond strength of protein lipid complexes caused by interaction of cholesterol with membrane components.

[Effect of sterols on erythrocyte membrane properties in experimental rickets].

Experimental rickets in rats was accompanied by a distinct increase in content of cholesterol and its esters, scvalene, lanosterol and 7-dehydrocholesterol in erythrocyte membranes with simultaneous decrease in content of total phospholipids. The alterations in lipid composition of erythrocyte membranes led to an increase in osmotic stability, to a decrease in glucose utilization and 45Ca incorporation into the erythrocytes. Acidic erythrogramms indicated an appearance in circulation of erythrocytes resistent to the effect of acidic hemolytics.

[Formation of 7-dehydrocholesterol ketoderivative - cholesta-4,7-dien-3-one in stomach and intestinal rat tissues].

Incorporation of [2-14C] sodium acetate into 7-dehydrocholesterol ketoderivative, cholesta-4,7-dien-3-on, was studied in the tissues of the rat stomach secretory and esophageal parts and in the mucous and serous membranes of the small intestine. Cholesta-4,7-dien-3-on is shown to form not from [14C]cholesterol but from [14C] dehydrocholesterol. Incorporation of the label into the compound under study is established to be maximum 6h after isotope administration.

[Effect of potassium orotate on metabolism in chickens under different provision with vitamin D3].

Vitamin D3 induction of the vitamin-D3-dependent proteins biosynthesis and certain indexes characterizing the rachitic state in animals were studied as affected by potassium orotate. Introduction of potassium orotate to the rachitogenic diet in combination with vitamin D3 is shown to normalize the processess of bone mineralization and to increase intensity of chicken growth. In duodenum mucosa with rachitis orotate normalizes the activity of alkaline phosphatase, raises the content of calcium-binding protein and stimulates the latter formation after administration of vitamin D3; orotate favours redistribution of the purine and pyrimidine nucleotides content.

[Effect of sterols of cholesterol series on secretion of hydrochloric acid in mucosa of animals].

Secretion of hydrochloric acid of frog gastric mucosa in vitro was studied as affected by some sterols of the cholesterol series. This effect is found to depend on both the sterol molecule structure and the substance concentration. 7-dehydrocholesterol and its products of oxidation are supposed to have a specific effect on the process of hydrochloric acid secretion.

[Study of hormonal activity of phytoecdysones on house fly larvae and codling moth caterpillars].

Preparations of ecdysterone, ponasterone A and sum of ecdysones isolated from the plant sources possess a high hormonal activity with respect to house fly larvae and codling moth caterpillars. The latter may be recommended for using as a sensitive test of the ecdysones hormonal activity.

[Guinea pig spinal cord sterols in allergic encephalomyelitis].

Composition of sterols of the guinea pigs spinal cord unsaponifiables fraction was studied with experimental allergic encephalomyelitis (EAE). It is established that under conditions of EAE the cholesterol content is decreased by 48% as compared to normal. The amount of latosterol lowers as well and is 2.

[Sterol content of rabbit erythrocyte membranes normally and in atherosclerosis].

The sterol composition of erythrocyte membranes was studied in norm and under experimental atherosclerosis. It is shown that in the normal animals the content of cholesterol in the membranes increases with age and practically reaches a relatively constant value by 5-6 months. In the experimental animals being on the atherogenic diet the amount of cholesterol in the membranes a month later is practically identical to the control.

[Effect of ultraviolet irradiation of different spectral composition on cholesterol synthesis in rat skin].

Irradiation of rats with of UV-radiation sources epsilonYB-15, (see article) causes a decrease in the intensity of 2-14C-acetate incorporation into cholesterol of skin and small intestine and simultaneous accumulation of radioactivity in its predecessors, namely in lathosterol and 7-dehydrocholesterol. Thus, it is shown that UV-irradiation of animals inhibits the cholesterol synthesis in skin and tissue of the small intestine. Intensity of cholesterol synthesis inhibition with UV-irradiation of animals depends on the spectral, composition of the acting radiation.

[Effect of thymosterin A on the immunological reaction of mice].

Proliferaiton of thymus-dependent lymphocytes and immunological reaction of the line CBA mice immunized with sheep erythrocytes was studied as affected by thymosterol A. The data obtained confirmed the authors' assumptions on a stimulation effect of thymosterol A on division of thymocytes. Introduction of the mentioned preparation against a background of the antigenic aciton of sheep erythrocytes causes an increase in the amount of cells synthesizing hemolysins more than by 60% as compared to the control.

[In vitro biosynthesis of cholesterol and its precursors in the osseous tissue of rats].

By thin-layer chromatography compounds of sterol origin were isolated from the nonsaponified fraction of bone tissue of rats. The occurrence of squalene, lanosterol, cholesterol and incompletely identified Cdelta2427-sterol in the organic matrix of the bone was demonstrated by means of UV- and IR-spectrometry. Bone tissue incubation with 1,2-C14-aceticacid yielded C14-labeled lanosterol, C28, 29-sterols, cholesterol and squalene.

[Chugaev's reaction for sterols].

Spectrophotometric patterns of Chugaev's reaction products of forty sterol compounds were studied. The reaction was shown to be used for identification and the quantitative determination of some sterols.

[Studies in the field of chemistry, biochemistry and photobiochemistry of sterols].

The article deals with a review of the results of studies performed at the Department of photobiochemistry of the A. V. Palladin Institute of Biochemistry of the Academy of Sciences of the Ukrainian SSR.

[Separate measurement of fluoroanalogues of desmosterol, cholesterol, 7-dehydrocholesterol by thin-layer and gas-liquid chromatography].

An attempt was made to develop a new method for separate measurement of sterols of similar chemical structure--desmosterol, cholesterol, 7-dehydrocholesterol--by means of thin-layer and gas-liquid chromatography. Fluoroanalogues of the sterols were well separated in the adsorbent thin layer. This facilitated their further identification, quantitation and accumulation.

[Sterols of horse erythrocytes].

Sterols of the whole erythrocytes, hemoglobin, membranes and their protein fractions were studied. Erythrocytes and their components were established to contain, besides cholesterol, other substances of the sterol nature. Cholesterol, 7-dehydrocholesterol and other substances of the cholesterol series are practically completely linked with the lipoproteid fractions of the erythrocyte membrane whereas all sterols found in the native erythrocytes in negligible amounts are bound with hemoglobin.

[Photoisomerization of provitamins D under influence of various ultraviolet radiation].

The influence of various sources of ultraviolet radiation on the photoisomerization of provitamins D--ergosterol and 7-dehydrocholesterol--was studied under industry-like conditions. The yield of previtamins and, consequently, vitamins D was higher with the use of erythemic lamps with luminophore E-2 and luminophore E-3 than with the use of lamps PRK-2.