[Dynamics of fatty acid composition of total lipids during embryonic development of Atlantic salmon Salmo salar L].

Dynamics of fatty acid composition of total lipids was studied for freshwater salmon Salmo salar L. during its embryonic development from blastula (3 hours) up to hatching (108 days) as well as in unfertilized eggs. Stable amount of total and some saturated, monounsaturated and polyunsaturated fatty acids (PUFA) of total lipids was observed during embryonic development. Considerable changes in fatty acid composition were observed at the stage of prelarvae hatching, i.e., significant decrease of (n-6) PUFA (18:2(n-6) and 20:4(n-6)) and (n-3) PUFA and increase of total and some saturated and monounsaturated fatty acids was registered. Change in saturation ratio of membrane lipids justifies the presence of the biochemical mechanism forwarded on regulation of cell membrane enzymes in accordance with the changes of internal physiological processes taking place in the organism and fluctuations of external environmental conditions or the preparation period (as reproduction). Data on peculiarities of transformation and utilization of fatty acids during salmon embryonic development may be used for understanding of their functional role in the developing organism as well as for assessing the quality of the caviar.

[Effect of aluminum and iron on lipid metabolism in aquatic invertebrates].

Methods of thin-layer, gas-liquid, and liquid chromatography were applied to the study of the effect of various concentrations of aluminum and iron salts on the contents of phospholipids, cholesterol, and fatty acids in the aquatic invertebrate Hydropsyche contubernalis L. (Trichoptera). It was found that the effect of the metals under study on lipid contents in living organisms depended on the composition of the aqueous medium and concentrations of the metals. Aluminum and iron altered the value of the cholesterol-to-phospholipid molar ratio. In the absence of lethal effects, this was indicative of attempts to switch adaptational biochemical mechanisms to stabilize cellular structures.

[Effect of gamma irradiation on the preference behavior and lipid metabolism in grey garden slug Deroceras reticulatum Mull]. / Viianie gamma-oblucheniia na preferntnoe povedenie i lipidnyi obmen u sliznia setchatogo Deroceras reticulatum Mull.

We studied the preference behavior of slugs Deroceras reticulatum in experimental light, thermal, and salt gradients. The zone of each gradients preferred by the majority of individuals had the lowest contents of total lipids and total fatty acids in the tissues as compared to animals in any other zones. Hard gamma irradiation of slugs D. reticulatum proved to induce qualitative changes in salt preference, to decrease photoresponse in light gradients, and to increase lipid content in tissues.

[Lipid metabolism of caddisfly larvae at low pH]. / Lipidnyi metabolizm lichinok rucheinikov pri nizkikh znacheniiakh pH sredy.

The influence of low pH (5.0 and 4.0) on lipid metabolism of caddisworms Hydropsyche contubernalis L. (Trichoptera) was studied in 48 h toxicity experiments. The results were correlated with lipid composition of caddisworms directly isolated from natural water. Phospholipids, cholesterol, mono-, di-, triacylglycerols, and fatty acids were detected by thin-layer and liquid chromatography. Minimal environmental changes were shown to initiate the biochemical adaptation mechanisms strengthening the cellular membranes through their condensation due to additional phospholipid and cholesterol synthesis. In the natural medium the adaptation processes are more active than in the artificial medium. More serious changes, such as pH decrease to 4.0, suppress the adaptation processes in the first medium and terminated them in the second one.

[Radionuclide study of blood flow in tumor and normal tissues of rats in induced hyperglycemia]. / Radionuklidnoe issledovanie krovotoka v opukholevoi i normal'noi tkaniakh krys pri iskusstvennoi giperglikemii.

Radionuclide angiography was performed in rats with transplantable tumors (sarcoma 45 and Walker carcinosarcoma 256). Induced hyperglycemia was shown to result in blood flow inhibition in tumor and normal tissues of tumor-bearing rats. Some differences were revealed in a degree of reversibility of blood flow disorders in tissues of the above strains. The results obtained confirmed the advisability of radiation therapy at the height of a decrease in tumor blood flow.

[Characteristics of the microstructure of biliary calculi based on data from scanning electron microscopy]. / Kharakteristika mikrostruktury zhelchnykh kamnei po dannym skaniruiushchei elektronnoi mikroskopii.

Scanning electron microscopy was employed to study cholelithic microstructure. Irrespective of the chemical composition, the gall-stones demonstrated the presence of a cementing matrix composed of micellar-vesicular particles occurring either in aggregates or regularly spreading along the facets about the surface of crystalloid structures. There appeared to be a close relationship between the latter and the particles which are, viz., vesicles, responsible for the plane and margin epitaxy of the cryslalloid structures. Any cholesterol deposits are lipoprotein-like particles or their derivatives, appearing as micellar-vesicular particles in case of choleliths.