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A new modern stage in the development of lipid biochemistry is presented: lipidomics, which emerged on the basic of new highly sensitive fractionation methods, primarily, mass spectroscopy. Lipidomics is defined mainly as systemic evaluation of all molecular types of lipids in an object, their cell functions, and molecules with which they react. Lipidomic approaches identifying picomole levels of individual lipids in combination with modern genome technology provide detailed information about the involvement of minor phospholipids in the cell signaling processes. Brief data on the functions of lysophospholipids as second messengers of signal transfer, their effects on cell processes, and possible involvement in the pathogenesis of some diseases are presented. It is expected that introduction of lipidomics in biomedical studies will promote the detection of targets for new drugs and development of new diagnostic tests.

There is increasing evidence that different phospholipids are involved in regulation of various cell processes and cell-cell interactions. Lysophospholipids (lysophosphatidic acid, lysophosphatidylcholine) and a number of lysosphingolipids play particular roles in these regulations. Their effects are mediated by specific G-protein-coupled receptors. G-Protein coupled signal transduction to the cell nucleus involving a chain of intracellular protein kinases induces the main effects in cells--growth, proliferation, survival, or apoptosis. This review summarizes recent data on various groups of lysophospholipid receptors and their cell signal transduction pathways.

This review considers various functional aspects of cell sphingolipids (sphingomyelin, ceramides) and lysosphingolipids (sphingosine-1-phosphate (S1P) and sphingosine phosphorylcholine). Good evidence now exists that they are actively involved in numerous cell-signaling processes. The enzymes responsible for formation and interconversion of cell sphingolipids (sphingomyelinases, ceramidase, sphingosine kinase, S1P-lyase) exhibit high sensitivity to various stimulating factors. This determines the content of individual cell sphingolipids and therefore the mode of cell response. Special attention is paid to preferential localization of sphingolipids in the rigid plasma membrane domains (rafts) coupled to many signal proteins. The suggestion is discussed that ceramide signaling may be based on the modification of fine molecular interactions in lipid rafts, resulting in its clusterization inducing the signal transduction. The review also highlights involvement of sphingolipids in cell proliferation, apoptosis, and in processes implicated to atherosclerosis.

The effects of grape phytoestrogens on cholesterol accumulation were studied in primary culture of human blood monocytes incubated with blood serum from postmenopausal women obtained before and 2, 4, and 6 h after single intake of plant components of grapes. Phytoestrogens from grape seeds, pressed out grapes, and fermented grape ridges prevent cholesterol accumulation in cells and can be regarded as prospective components for the development of natural preparations for the prevention of atherosclerosis in postmenopausal women.

The review highlights the membrane aspect of cholesterol efflux from cell membranes to high density lipoproteins (HDL), an initial stage of reverse cholesterol transport to liver. Special attention is paid to ABC-A1 transporter and membrane SR-B1 receptor, their properties, putative mechanisms of action and their role in reverse cholesterol transport. Interaction of ABC-AI with plasma free apoA1 is suggested to facilitate the efflux of membrane phospholipids and formation of their complex with apoAI. Then this complex accepts the membrane cholesterol, with lipidation till the full HDL particle is formed. For a number of cells the correlation of cholesterol efflux into HDL with SR-BI expression was shown. The reversible binding of receptor SR-BI with HDL is supposed to influence molecular organization of membrane lipids, that promotes the efflux of cholesterol molecules out of the membrane.

Relationship between presence of coronary heart disease (CHD), coronary risk factors (parameters of lipid transport system and hypertension) and disturbances of microcirculation was studied in patients with myeloproliferative blood disease Polycythemia Vera (PV). Probability of tissue (including blood vessel wall) cholesterol accumulation was estimated by measurement of its content in skin surface layers. PV patients (n=55, including 27 patients with CHD) had predominant hypolipoproteinemia with normal proportion of various lipoprotein classes. Absence of substantial increase of skin surface cholesterol content both in patients with and without CHD was considered to be a sign of low probability of the presence of severe atherosclerotic processes. However patients with CHD had substantially more pronounced disturbances of microcirculation. Basing on these data the authors suggest that CHD in PV patients had non-lipoprotein genesis and present discussion of alternative mechanisms of vascular changes.

The Wilhelmy balance was used for in vitro testing of surface active properties of natural phosphatidylcholines (PCs) as possible basis for surfactant replacement therapy. Saturated PC, dipalmitoylphosphatidylcholine (DPPC) and phospholipon (PL) had similar parameters of surface activity: minimal values of equilibrium surface tension (EST) and the longest surface spreading time (SST). Unsaturated egg and soybean PCs also shared similar values of surface activity parameters (EST and SST). Correlation between fatty acid saturation of PCs and EST or SST allows to consider both these parameters as informative ones for surface tension evaluation in the search of components for artificial surfactant. Since parameters of DPPC and PL surface activity are equivalent in their performance, they may be potentially employed for testing instead of DPPC as a possible base for artificial surfactant.

Cholesterol (CH) acceptance ability of high density lipoproteins (HDL) was assessed in 43 ischemic heart disease (IHD) patients, including patients with post-infarction cardiosclerosis and class II-III effort angina. CH acceptance ability of HDL was measured as increment of HDL CH after incubation with artificial CH-containing system. Oxidabilities of HDL and total plasma were estimated by quantitation of lipid peroxidation products (hydroperoxides and thiobarbituric acid-reactive substances - TBARS) after incubation with Cu(2+) ions. HDL fraction (after apo B lipoproteins removal) of IHD patients appeared to include 2 times less additive CH compared with donor's HDL despite lower (-12%) HDL CH level. Negative correlation (r =-0.38, p<0.05) existed between formed TBARS in HDL and HDL CH acceptance. In total plasma of IHD patients elevation of both formed TBARS and particularly hydroperoxides was observed. Parallelism between decrease of CH acceptance by HDL, oxidability of HDL and of total plasma testifies on weakness not only of CH-accepting, but also of antioxidant HDL functions in IHD patients.

Relative cholesterol content and its distribution between erythrocytes and plasma were studied in 34 patients with polycythemia vera (PV) both with and without concomitant coronary heart disease (CHD). Deformability of erythrocytes, disturbances of microcirculation (blood flow fragmentation, decrease of capillary density) were also assessed. Erythrocytes cholesterol/phospholipids molar ratios (0.68+/-0.03) in patients was lower than normal value (0.8) in spite of decreased cell deformability. This was associated with some increase of peroxidation products. Blood cholesterol distribution between cell and plasma species had some peculiarities caused by high hematocrit: compared with normal value erythrocytes of patients carried relatively larger portion of total blood cholesterol (23.7+/-0.8% and 27-31%, respectively). However in CHD patients these values were significantly lower with correspondent increase of plasma cholesterol quota. This allowed to suggest possible protective role of blood cholesterol redistribution in polycythemia patients, through erythrocytes trafficking of some part of plasma cholesterol.

Cholesterol of high density lipoprotein (HDL) subfractions (HDL2 and HDL3), activity of cholesterol ester transport protein (CETP), and standard lipoprotein parameters (cholesterol, triglycerides, HDL cholesterol) were measured in plasma of 192 patients with various psoriasis forms, which included simple "distributed psoriasis", erythrodermic and arthropathic psoriasis. Among psoriatic patients unusually high percent of persons with both hypo- and hyper-cholesterolemia was observed. The same situation was observed with frequency of cases with both low and high plasma HDL cholesterol levels, the distribution being depending from disease severity. In contrast to norm, psoriasis patients had big range not only in HDL2 cholesterol level, but also in HDL3 cholesterol. They also had decreased CETP activity. Data obtained suggest the existence of changes in reverse cholesterol transport system in psoriasis, which may influence skin cell proliferation (via control of cell supply with cholesterol).

Using the methods of surface balance we compared surface activity of different natural phosphatidylcholines. Dipalmitoylphosphatidylcholine, the principal component of natural surfactant, is characterized by less rapid spreading on the air-water interface compared to unsaturated yolk and soybean phosphatidylcholines, while the absolute rate of surface tension reduction was the same for all test lecithines. The surface activity of modified saturated soybean phosphadtidylcholine (Phospholipon) was similar to that of dipalmitoylphosphatidylcholine. The relationship between saturation of fatty acids in the molecule of phosphatidylcholine and the time of spreading on the air-water interface revealed in this study allows to use this parameter together with equilibrium surface tension for evaluation of surface activity when testing synthetic surfactant constituents.

The effects of Fe2+ ions on haemolysis induced by previously photooxidized psoralen (POP-haemolysis) were investigated. It was shown that POP-haemolysis was strongly activated by Fe2+ ions when ferrous ions were added to erythrocytes just after addition of POP. If POP was preincubated with Fe2+ before mixing with erythrocytes, then POP completely lost its ability to induce haemolysis. These data indicate the peroxidic nature of POP products responsible for haemolysis.

The parameters of cholesterol (CS) metabolism in the epidermis, blood plasma lipoproteins, and red cell membranes were assessed in patients with psoriasis. The levels of free and total CS in extracts from the surface of epidermis, in plasma lipoproteins, and in plasma triglycerides were measured, and the molar ratio CS/ phospholipids (CS/PL index) in red cell membranes assessed in 194 patients with psoriasis of different severity. The levels of free and total CS in the epidermis were found to increase as the psoriatic process grew in severity. These shifts manifested even in apparently intact skin sites, which indicated the primary nature of total-system disorders. As for the plasma lipids, statistically reliable changes were observed only for the relative level of free cholesterol of the plasma and, most of all, high-density lipoproteins. These values for the mean parameters in the five groups of examinees correlated (r from 0.71 to 0.92) with the levels of total and free CS in the epidermis. Contrary to it, the levels of total CS and triglycerides in the plasma had a tendency to decrease as the severity of the psoriatic process augmented. Such a trend was statistically reliable for the CS/PL index, which increased in all the patients except the most grave, this increase being the more, the less grave the disease was; this was manifested in an inverse correlation (r = 0.9, on average) with the epidermal CS. The detected uncommon relationship between CS values in the epidermis, plasma lipoproteins, and biological membranes indicates heretofore unknown features of metabolic disorders in psoriasis.

The levels of epidermal total, free and esterified cholesterol were studied in psoriatic patients. Lipids were isolated from the areas of psoriatic lesions and from the normally appearing epidermis by the authors' non-invasive surface extractive method. The quantity of cholesterol was given in microgram per square centimeter. Fifty six and 11 healthy persons were examined. The skin cholesterol levels were twice-four-fold higher in the patients than in the healthy subjects. The same levels were noted from the areas of lesion and from normally appearing epidermis. The proportion of an esterified fraction decreased mainly in the normally appearing epidermis areas, especially in severe psoriasis. The role of the findings was also discussed.

Proceeding from published data on lipid content and composition in human skin and on the possible relationship between cholesterol level in skin biopsy specimens and status of blood vessels, the authors measured cholesterol content in skin layers available for external extraction in patients with atherosclerosis with different types of dyslipoproteinemias. Effective conditions of extraction were developed permitting after external rapid atraumatic treatment extraction of the maximally possible amount of cholesterol, 1.5 to 1.6 mkg from 1 cm2 of the palm skin surface, this being a constant value for each examinee (coefficient of variations after 3-4 repetitions 5%). Though slight, but statistically reliable increase of the amount of surface-extractable cholesterol was observed in atherosclerosis patients. This parameter did not correlate with the blood serum concentration of lipid components. A correlation (r = 0.54, p < 0.001) was observed with an only serum lipoprotein parameter, the so-called dyslipoproteinemia coefficient representing the sum of "atherogenic" parameters (cholesterol+triglycerides) divided by alpha-lipoprotein cholesterol. Measurements of surface-extractable skin cholesterol may be used as an available discriminant of atherosclerosis; the method seems to find application in other diseases as well.

The effect of the cholesterol content in liposomes on their interaction with blood serum lipoproteins has been studied. It was shown that phosphatidyl choline liposomes without cholesterol did not interact selectively with any class of serum lipoproteins. At the same time, addition of high cholesterol concentrations to liposomes confers to them a new feature, namely the ability to interact selectively with the serum low density lipoproteins. Up to 90% of such lipoproteins can interact with liposomes. This finding was confirmed by "in vivo" data. The observed effect of "address" properties given to liposomes by a native lipid may be of interest in search for new possibilities to use liposomes for selective delivery of drugs.

The interaction of liposomes containing different amounts of cholesterol with human serum low density lipoproteins was investigated. Efficiency of the interaction depended on the cholesterol content of liposomes and was highest for liposomes with the maximal cholesterol/phospholipid molar ratio. The latter selectively and effectively interacted with low density lipoproteins, with up to 90% of lipoprotein particles interacting with liposomes in serum. Fusion of the particles with liposomes was observed during the interaction.

Quick model of experimental atherosclerosis--3 weeks of cholesterol feeding and 3 weeks of standard diet for aorta atheromatosis development--was used in rabbits. Then one group of animals was fed 1 month by plant oil of specific composition, with added omega-3 (linolenic) fatty acid, and the other group received the same dose of fish oil. The most intensive decrease of plasma cholesterol and erythrocyte cholesterol/phospholipid ratio was in rabbits, that received the oil with linolenic acid. Triglyceride level decreased gradually in all animal groups in the same degree, and HOL cholesterol did not change. After the end of experiment the aorta damage degree in group, that received plant oil with linolenic acid, was only 10.8%, as compared with 36.2% in control group (without treatment) and 39.3% in rabbits, that received fish oil. The absence of fish oil effect supports the earlier data about rabbits specific sensitivity to this product resulting in possible hepatotoxic effect. The data indicates on the usefulness of rabbit model in fish oil effects investigations, and also on the positive, antiatherogenic effect of plant oil with added linolenic acid.

Micromethod of quantitative differentiation of keratin SH-groups has been established. It lets define SH-groups of cysteine in polypeptide chain in range of 0.05-0.07 mg/ml.

Basing on the data of Bouissou et al. on an increase of cholesterol content in the skin biopsies in atherosclerosis patients, the cholesterol amount was evaluated after superficial atraumatic rapid treatment of patients palm skin. The optimization of the extraction conditions was performed: the surface skin cholesterol value was constant for individual subjects (variability factor 5%). The range of this value was 1.5-6 Mg/cm2 and it was higher for atherosclerotic patients. No correlations with any conventional plasma lipoprotein parameters were observed. At the same time positive correlation (r = 0.54. p < 0.01) was observed with dyslipoprotein coefficient--(Ch+TG/alpha-Ch). Possible diagnostic significance of this skin cholesterol parameter is discussed.

Therapeutic effect of corn oil was studied in rabbits with alimentary atherosclerosis. Corn oil was administered (2 ml/kg, 30 days) after the completion of cholesterol diet unlike studies, where they were administered simultaneously. Total cholesterol, apoB-lipoprotein cholesterol and triglycerides decreased more intensively in rabbits fed by corn oil than in control group. No changes in high-density lipoprotein cholesterol were observed. The most pronounced effect was noted in aorta morphological analysis: an aorta damage degree was 4.8% as compared with 52.9% in the control group. The results show that available plant oils with omega-6 polyunsaturated fatty acids (PUFA), in particular corn oil, may as well as omega-3 PUFA be used as the base for antiatherogenic preparations.

The effects of polyene phosphatidylcholine (PPC) treatment at oral and intravenous administration to rats and rabbits in hypercholesterolemic diet were studied. No aorta damage was observed in either of rat groups. But fatty liver appeared, and it was the greatest in rats, who received cholesterol and PPC. The result may be attributed to adaptive protection of peripheral tissues due to high experiment duration (18 months) in the state of active reverse cholesterol transport (RChT). No antiatherogenic effect was noted in rabbits at PPC administration (170 mg/kg), while its intravenous injection (50 mg/kg) resulted in marked reduction of plasma cholesterol level, elevation of HDL cholesterol and decrease of the extent of aorta damage. The conclusion is drawn on the ppc high antiatherogenic effect predominantly at intravenous administration, and on advisability of its use in cases of RChT deficiencies, as its activator.

Intraspecies variation in diet-induced hypercholesterolaemia in rabbits, simulating atherosclerosis, was studied. The chinchilla rabbit population examined contained several subpopulations, as indicated by polymodal forms of histograms of plasma cholesterol levels. This finding indicates that the inclusion of subpopulations in an investigation can lead to erroneous conclusions, and that subpopulations should be identified before such work is undertaken. The relationship between the molar cholesterol/phospholipid ratio in rabbit erythrocyte membranes and the plasma cholesterol level in experimental atherosclerosis was also studied. A correlation was evident only over the range of 1-5 g cholesterol per litre of plasma.

Oxidative modification of cholesterol on the surface of fluorocarbon emulsions was studied. The oxidation yielded one primary product--7-peroxycholesterol. It was shown that the obtained cholesterol C7 derivatives possess a high biological activity. It was concluded that the possibility of oxidative modification of plasma substances on the surface of fluorocarbon emulsion particles with the formation of highly active compounds must be taken into account when using the fluorocarbon particles in medicine.

Formation of biologically active oxidized derivatives of cholesterol as a result of its oxidation on the surface of fluorocarbon emulsions was studied. A single product of cholesterol oxidation, 7-peroxycholesterol, was found. It was shown that 7-peroxycholesterol and its derivative 7-keto-cholesterol inhibit the rosette formation between human T-lymphocytes and sheep erythrocytes. These substances exert a strong cytostatic action on the growth of procaryotic and eucaryotic cell cultures. Thus, oxidative modification of blood plasma components on the surface of fluorocarbon emulsion particles with the formation of highly active compounds must be taken into account when using the fluorocarbon emulsions in medicine.

A sorbent specific for cholesterol enabled to isolate effectively the substance from blood plasma and membranes of erythrocyte shadows. Cholesterol was not isolated from microsomal membranes neither with the sorbent MGU-I nor by means of phospholipid liposomes. The phenomenon was apparently related to the localization of cholesterol on the inner surface of lipid bilayer of microsomal membranes.

Activity of lecithine-cholesterol acyltransferase (LCAT) was studied in blood of 26 patients with atherosclerosis of various localization after course of treatment involving three-fold hemosorption. The initial activity of the enzyme, decreased distinctly as compared with normal state, was dissimilarly altered during hemosorption. The system LCAT-HDLP was stabilized after the third hemosorption. These results relevant to programming hemosorption therapy of patients with atherosclerosis.

Concentrations of cholesterol, triglycerides and the molar ratio cholesterol/phospholipids were higher while the values of cholesterol in high density lipoproteins (HDL) was lower in blood of patients with obliterating peripheric atherosclerosis as compared with control values. After extracorporal haemosorption on columns with activated charcoal and preadministration of heparin all the patterns studied were decreased, thus indicating the sorption of all the lipoprotein classes, including anti-atherogenic HDL, simultaneously with lipolysis of very low density lipoproteins, triglycerides as well as the sorption and destruction of large erythrocytes containing relatively high amount of cholesterol. Within the subsequent period all the patterns studied returned to the initial level. At the same time, concentration of HDL cholesterol, which, as shown earlier, correlated inversely with severity of clinical manifestations in the patients, continued to increase, exceeding the initial level by 39% within 7-14 days; these data were also corroborated by polyacrylamide gel disc electrophoresis. The alterations found may be among the factors, responsible for favourable clinical effect of haemosorption in the patients with peripheric atherosclerosis. Possible reasons for the HDL concentration increase are discussed.

It has been shown in chronic experiments on dogs with reversible disorders of the coronary circulation that the sequels of a 3-5-minute reversible myocardial ischemia might be identified throughout 24-120 hours by an original method suggested by the authors. The method is based on the diagnosis of latent postischemic leukocytosis and other associated hematological shifts.

Reverse correlation between content of cholesterol in lipoproteins of high density (LPHD) and severity of clinical manifestations was observed in patients with obliterating atherosclerosis of legs. Concentrations of cholesterol, triglycerides and LPHD cholesterol were normal in the majority of patients but dyslipoproteinemia of various types including hypo-alpha-lipoproteinemia, was noted in some patients. The molar ratio "cholesterol/phospholipids" was increased in erythrocytes of the patients examined, demonstrating the disbalance in cholesterol turnover between the cell membranes and blood lipoproteins.