Growth Hormone, Insulin-Like Growth Factor-1, Insulin Resistance, and Leukocyte Telomere Length as Determinants of Arterial Aging in Subjects Free of Cardiovascular Diseases

Background: Increased arterial stiffness (AS), intima-media thickness (IMT), and the presence of atherosclerotic plaques (PP) have been considered as important aspects of vascular aging. It is well documented that the cardiovascular system is an important target organ for growth hormone (GH) and insulin-like growth factor (IGF)-1 in humans, and GH /IGF-1 deficiency significantly increases the risk for cardiovascular diseases (CVD). The telomere length of peripheral blood leukocytes (LTL) is a biomarker of cellular senescence and that has been proposed as an independent predictor of (CVD). The aim of this study is to determine the role of GH/IGF-1, LTL and their interaction cardiovascular risk factors (CVRF) in the vascular aging. Methods: The study group included 303 ambulatory participants free of known CVD (104 males and 199 females) with a mean age of 51.8 ± 13.3 years. All subjects had one or more CVRF [age, smoking, arterial hypertension, obesity, dyslipidemia, fasting hyperglycemia, insulin resistance-HOMA (homeostatic model assessment) >2.5, or high glycated hemoglobin]. The study sample was divided into the two groups according to age as "younger" (m ≤ 45 years, f ≤ 55 years) and "older" (m > 45 years, f > 55 years). IMT and PP were determined by ultrasonography, AS was determined by measuring the carotid-femoral pulse wave velocity (c-f PWV) using the SphygmoCor system (AtCor Medical). LTL was determined by PCR. Serum IGF-1 and GH concentrations we measured by immunochemiluminescence analysis. Results: Multiple linear regression analysis with adjustment for CVRF indicated that HOMA, GH, IGF-1, and LTL had an independent relationship with all the arterial wall parameters investigated in the younger group. In the model with c-f PWV as a dependent variable, p < 0.001 for HOMA, p = 0.03 for GH, and p = 0.004 for LTL. In the model with IMT as a dependent variable, p = 0.0001 for HOMA, p = 0.044 for GH, and p = 0.004 for IGF-1. In the model with the number of plaques as a dependent variable, p = 0.0001 for HOMA, and p = 0.045 for IGF-1. In the older group, there were no independent significant associations between GH/IGF-1, LTL, HOMA, and arterial wall characteristics. Conclusions: GH/IGF-1, IR, HOMA, and LTL were the important parameters of arterial aging in younger healthy participants.

Atorvastatin Therapy Modulates Telomerase Activity in Patients Free of Atherosclerotic Cardiovascular Diseases

Background: Telomerase activity (TA) is considered as the biomarker for cardiovascular aging and cardiovascular diseases (CVDs). Recent studies suggest a link between statins and telomere biology that may be explained by anti-inflammatory actions of statins and their positive effect on TA. Until now, this effect has not been investigated in prospective randomized studies. We hypothesized that 12 months of atorvastatin therapy increased TA in peripheral blood mononuclear cells. Methods: In a randomized, placebo-controlled study 100 hypercholesterolemic patients, aged 35-75 years, free of known CVDs and diabetes mellitus type 2 received 20 mg of atorvastatin daily or placebo for 12 months. TA was measured by quantitative polymerase chain reaction. Results: At study end, 82 patients had sufficient peripheral blood mononuclear cells needed for longitudinal analysis. TA expressed as natural logarithms changed from 0.46 ± 0.05 to 0.68 ± 0.06 (p = 0.004) in the atorvastatin group and from 0.67 ± 0.06 to 0.60 ± 0.07 (p = 0.477) in the control group. In multiple regression analysis, atorvastatin therapy was the only independent predictor (p = 0.05) of the changes in TA independently of markers of chronic inflammation and oxidative stress. Atorvastatin therapy was associated with increases in interleukin-6 within the normal range and a tendency toward reduction in blood urea. Conclusion: These initial observations suggest atorvastatin can act as telomerase activator and potentially as effective geroprotector. Trial registration: The trial was registered in ISRCTN registry ISRCTN55050065.

[The application of lipoprint-system for analysis of sub-fractional spectrum of lipoproteins of blood serum.]

The lipoproteins of low and high density are presented by heterogeneous specter of particles differing by size, density, charge, composition and functional characteristics. The prevalence of small dense particles of lipoproteins of low and high density in blood plasma is associated with higher risk of development of coronary heart disease. The identification of subfractional spectrum of lipoproteins in clinical purposes is complicated because of requirement of expensive equipment and reagents and extended time of implementation. The lipoprint-system (Quantimetrix Lipoprint LDL/HDL System, USA) based on the vertical electrophoresis using 3% polyacrilamid gel, permits shortening time of sub-fractioning of lipoproteins up to three hours. In the spectrum of apoB-containing lipoproteins of very low density, intermediate density, C, B, A, lipoproteins of low density 1 and 2, small dense (lipoproteins of low density 3-7) are singled out. In the spectrum of lipoproteins of high density up to 10 sub-fractions associated in three groups and represented by large (lipoproteins of high density 1-3), intermediate (lipoproteins of high density 4-7) and small (lipoproteins of high density 8-10) particles are singled out. The article describes technique of identification of spectrum of particles of lipoproteins of low and high density in human blood serum. The conditions of implementation of experiments are presented. The advantages and limitations of technique are indicated. The number of examples of application of indices of sub-fractional spectrum of lipoproteins as additional markers of evaluation of aterogenity of lipid profile are presented. The conclusion is made concerning possibility of application of technique in clinical laboratory diagnostic.

[Age-related Changes of Left Ventricular Diastolic Function, NT-proBNP Level and Their Association with Leukocyte Telomere Length]

With advancing age the left ventricle (LV) undergoes structural and functional changes, thereby creating the substrate for the development of diseases. One possible mechanism of the ageing of the heart is cellular senescence. Leukocyte telomere length (LTL) is a marker of replicative ageing. The purpose of this study was to evaluate the diastolic function of LV and level of NT-proBNP in people of different ages free of cardiovascular diseases and to assess their relationship with LTL. Our data showed that old age is associated with diastolic dysfunction and increase in the levels of NT-proBNP. The group of older subjects had lower values of E/A (0.96+/-0.036 vs 1.27+/-0.03, p<0.001), Em/Am (0.9+/-0.035 vs 1.5+/-0.066) and higher values of IVRT (81+/-1.56 vs 70+/-1.23 s, p<0.001), DT (198+/-3.98 vs 175+/-2.82 s, p<0.001), that reflected impairment of LV relaxation. NT-proBNP level was higher in the elderly (100.82+/-7.1 vs 48.47+/-6.7 g/ml, p<0.01), but it did not correlate with LTL. The most sensitive to the age parameters of LV diastolic function (E/A and Em/Am ratio) were positively and independently of age associated with LTL (p<0.001). Older individuals with shorter LTL had significantly lower values of E/A ratio.

CONCLUSION

Telomere length appears to be a biomarker of myocardium ageing.

[Age-related Changes of Left Ventricular Diastolic Function, NT-proBNP Level and Their Association With Leukocyte Telomere Length]

With advancing age the left ventricle (LV) undergoes structural and functional changes, thereby creating the substrate for the development of diseases. One possible mechanism of the ageing of the heart is cellular senescence. Leukocyte telomere length (LTL) is a marker of replicative ageing. The purpose of this study was to evaluate the diastolic function of LV and level of NT-proBNP in people of different ages free of cardiovascular diseases and to assess their relationship with LTL. Our data showed that old age is associated with diastolic dysfunction and increase in the levels of NT-proBNP. The group of older subjects had lower values of E/A (0.96 ± 0.036 vs 1.27 ± 0.03, p < 0.001), Em/Am (0.9 ± 0.035 vs 1.5 ± 0.066) and higher values of IVRT (81 ± 1.56 vs 70 ± 1.23 MS, p < 0.001), DT (198 ± 3.98 vs 175 ± 2.82 MS, p < 0.001), that reflected impairment of LV relaxation. NT-proBNP level was higher in the elderly (100.82 ± 7.1 vs 48.47 ± 6.7 ωg/ml, p < 0.01), but it did not correlate with LTL. The most sensitive to the age parameters of LV diastolic function (E/A and Em/Am ratio) were positively and independently of age associated with LTL (p < 0.001). Older individuals with shorter LTL had significantly lower values of E/A ratio.

CONCLUSION

Telomere length appears to be a biomarker of myocardium ageing.

[Clinical value of insulin resistance in fasting normoglycemia]

Aim of the study was to clarify the question of the presence of manifestations of insulin resistance (IR) in fasting normoglycemia and to assess their association with risk of development and presence of clinically overt cardiovascular diseases (CVD) caused by atherosclerosis. We included into this study 1127 men and women older than 55 years with normal blood serum level of glucose in fasting state (&lt;6.1 mmol/l) without diabetes mellitus selected from a random sample of Moscow inhabitants (n=1186). In participants selected for this study we determined risk factors, calculated indexes of IR (HOMA-IR) and functional capacity of pancreatic -cells (HOMA-%B) using fasting levels of glucose and insulin. The examined subsample was divided into quartiles according to values of HOMA-IR. It was shown that in the 4-th quartile HOMA-%B was substantially higher than in other quartiles. With this values of body mass index and waist circumference were also highest in the 4-th quartile. Fasting insulin level compared with glucose level contributed more to determination of values of indexes of both IR and functional capacity of pancreatic -cells. In the upper 4-th quartile signs of atherogenic dyslipidemia appearing as higher concentration of triglycerides and lowered concentration of high density lipoprotein cholesterol manifested to the greatest degree. At statistical analysis of probability of CVD with clinical manifestations it was shown that in the 4-th quartile of distribution of HOMA-IR (&gt;2.7) values of odds ratio (OR) of development of arterial hypertension (AH), total CVD, angina pectoris, history of brain stroke were elevated. With that in the 3-rd quartile of distribution i.e. at HOMA-IR &gt;1.9 there were higher ORs of development of AH, CVD, angina pectoris. Thus even in the range of normal fasting glucose concentrations in subjects older than 55 years we detected IR associated with elevated risk of development of atherosclerosis related CVD. For detection of IR it is appropriate to measure in blood serum not only concentration of glucose but also fasting insulin level with subsequent calculation of HOMA-IR and HOMA-%B indexes.

Parameters of high-density lipoproteins in patients with arterial hypertension in combination with other components of metabolic syndrome

Parameters of HDL (concentrations of cholesterol, apoprotein A1, and phospholipids and phospholipid composition) determining their functional properties were studied in patients with arterial hypertension in combination with other components of metabolic syndrome (abdominal obesity, hyperlipidemia, and impaired glucose tolerance). Patients with isolated arterial hypertension did not differ from the control group by the concentration of apoprotein A1 and HDL cholesterol, but had lower content of HDL phospholipids and changed phospholipid composition: lower ratio of phosphatidylcholine and higher relative contents of lysophosphatidylcholine, sphingomyelin, and phosphatidylethanolamine. Parameters of HDL in patients with arterial hypertension associated with other components of metabolic syndrome did not differ from those in patients with isolated arterial hypertension. The observed changes in HDL in patients with arterial hypertension alone or in combination with other components of metabolic syndrome can impair functional capacity of HDL in reverse cholesterol transport, which increases the risk of atherosclerosis.

[Metabolic peculiarities of dyslipoproteinemias unrelated to high level of blood cholesterol]

The aim of this study was to reveal whether atherogenic or nonatherogenic properties of dyslipoproteinemias (DLP) not related to high level of blood total cholesterol (C) and low density lipoprotein C (LDL C) are determined only by shifts in serum triglycerides (TG) and/or high density lipoprotein cholesterol (HDL C) levels, or by other lipoprotein system alterations, if any. Biochemical factors regulating both lipid and carbohydrate metabolism were analyzed in two subsamples of Moscow residents aged 55 years with DLP: "high TG and low HDL C" and "normal TG and high HDL C" in comparison with randomly selected subsample assumed as "normal". Specific biochemical indexes of atherogenicity of DLP "high TG and low HDL C" were found, namely: increased apo B/AI ratio; disturbed functional activity of HDL in promoting reverse cholesterol transport expressed as elevated apo AII/AI ratio, decreased apo AI and phospholipids (PL) levels, decreased ratios of C/apo AI and C/PL in HDL, and decreased cholesterol-accepting capacity of HDL. Moreover, while fasting glucose level in subjects from this group remained unchanged, their fasting insulin level and HOMA-IR index were increased. Thus, DLP "high TG and low HDL C" is characterized by some specific metabolic features underlying its involvement into pathogenesis of atherosclerosis and type 2 diabetes mellitus. On the other hand, differences in biochemical parameters of antiatherogenic DLP "normal TG and high HDL C" from random subsample appeared to be opposite to differences from random subsample found for DLP "high TG and low HDL C", being in line with the present concept about their role in determining the antiatherogenicity of this kind of DLP.

Association of serum apolipoprotein A-II concentration with combined hyperlipidemia and impaired glucose tolerance

We studied the relationship of serum apolipoprotein A-II concentration with biochemical parameters of lipid and carbohydrate metabolism, type of hyperlipidemia, and insulin sensitivity in male patients with hyperlipidemia. High concentration of apolipoprotein A-II was associated with increased indices of atherogenic lipoproteins and high-density lipoprotein-mediated reverse cholesterol transport, combined hyperlipidemia, and decreased insulin sensitivity calculated with consideration for glucose and insulin levels in glucose tolerance test and body weight.

Impaired antiatherogenic function of high-density lipoproteins in the presence of various risk factors for coronary heart disease

We studied acception of cholesterol from Fu5AH hepatoma cells by blood serum from subjects with normal level of high-density lipoprotein cholesterol and hyperlipidemia (alone or in combination with other risk factors for coronary heart disease). Cholesterol-binding activity of high-density lipoproteins decreased in subjects with hyperlipidemia alone or in combination with excess body weight and/or arterial hypertension. Impairment of high-density lipoprotein activity was associated with changes in their phospholipid composition.

Simvastatin and Preparation of Polyunsaturated Phospholipids Produce Similar Changes in the Phospholipid Composition of High-Density Lipoproteins during Hypercholesterolemia

We studied the phospholipid composition of high-density lipoproteins in patients with coronary heart disease and hypercholesterolemia treated with simvastatin (Zocor, inhibitor of the key enzyme of cholesterol synthesis) and preparation of polyunsaturated phospholipids (lipostabil forte). Simvastatin produced a hypolipidemic effect and modulates the phospholipid composition of high-density lipoproteins (similarly to lipostabil forte). These changes contribute to functional activity of high-density lipoproteins in the reverse cholesterol transport.

[Signs of metabolic syndrome in combinations of hypertension with coronary risk factors]

Anthropometric data, parameters of lipoprotein spectrum and carbohydrate metabolism were obtained from 115 men aged 34-67 years with hypertension. Hypertension combined with any other criterion of metabolic syndrome was associated with deviations of parameters of insulin resistance, blood pressure, body mass index, waist circumference, levels of cholesterol, low density lipoproteins and lipoprotein (a) similar to those observed in complete metabolic syndrome. Combinations of hypertension with hypercholesterolemia and/or excessive body mass were not associated with signs of insulin resistance in the presence of higher then in isolated hypertension values of body mass index, cholesterol, low density lipoprotein cholesterol.

[Lowering of antiatherogenic significance of high density lipoproteins in obese persons]

Protein and lipid components of blood serum high density lipoproteins (HDL) responsible for their functional activity were studied before and after fat load in subjects with normal body mass and various types of obesity. Subjects with abdominal obesity compared with those with gluteo-femoral obesity and normal body mass initially had pronounced disturbances in components of HDL and their acceptor capacity. Fat load caused changes of HDL composition in all study groups. Postprandial effect in persons with normal body mass became obvious 6 hours after load while in those with excess mass it occurred earlier - 3 hours after fatty meal. In subjects with gluteo-femoral obesity this effect remained on the same level while in those with abdominal obesity it became more pronounced by hour 6. Contrary to subjects with normal body mass and gluteo-femoral obesity fat load induced changes of HDL components in persons with abdominal obesity were not associated with augmented acceptor capacity of HDL what could be considered as proatherogenic effect.

[High density lipoprotein composition in moscovites with low and high HDL cholesterol level]

AIM

To elucidate if there are any peculiarities in HDL composition in Muscovites with different HDL C levels, and to reveal which HDL components could determine the disturbances in their antiatherogenic properties at higher HDL C level.

MATERIAL AND METHODS

Sixty men aged 40-59 years with low HDL C level < 40 mg/dl (36 +/- 0.8 mg/dl; n = 30) and high HDL C level > 50 mg/dl(58 +/- 1.6 mg/dl; n = 30) were compared. Enzymatic, immunonephelometric methods and thin-layer chromatography were used.

RESULTS

Men with high HDL C level had higher concentration of apo AI, HDL phospholipids (PL), ratios of HDL C/apo AI and HDL C/HDL PL but lower ratio of HDL C free/HDL PL. The analysis of HDL PL composition revealed in subjects with high HDL C higher proportion of phosphatidylcholine (PC) and lower lysoPC, whereas the relative content of sphingomyelin and phosphatidylethanolamine did not differ between the groups.

CONCLUSION

The peculiarities in components of HDL found among men with different HDL C levels could explain less effective HDL atheroprotective properties in Muscovites with elevated HDL C.

[C-reactive protein and defect in lipid transport blood system in patients with rheumatoid arthritis]

In 88 patients with rheumatoid arthritis lipid-protein spectrum of the blood serum were determined biochemically and by means of nefelometric technique, C-reactive protein (CRP) was measured with enzyme immunoassay. An increase in CRP concentration was associated with lowering of apoA1 and HDL FL, triglycerides. Thus, elevation of CRP in RA reflects not only activity of inflammation but also defects in serum lipid-transport system by the atherogenic type.

Effects of simvastatin on the phospholipid composition of high-density lipoproteins in patients with hypercholesterolemia

We studied the phospholipid composition of high-density lipoproteins in patients with hypercholesterolemia before and after treatment with simvastatin. Individual phospholipids were separated by thin-layer chromatography on glass plates coated with silica gel. It was found that apart from hypolipidemic effect, simvastatin changed the concentration and phospholipid composition of high-density lipoproteins, which improved their cholesterol-accepting and cholesterol-transporting properties.

Phospholipid composition of high-density lipoproteins reflects lipolysis of triglyceride-rich lipoproteins during hyperlipidemia

We studied phospholipid composition of high-density lipoproteins in patients with normo- and hypertriglyceridemia treated with various hypolipidemic preparations (simvastatin and fenofibrate). Both preparations changed phospholipid composition of high-density lipoproteins and improved their functional activity. The differences in the phospholipid composition of high-density lipoproteins were probably related to lipolysis of triglyceride-rich lipoproteins catalyzed by lipoprotein lipase and, in particular, hepatic lipase.

Effects of alcohol on the major steps of reverse cholesterol transport

The effects of moderate alcohol consumption on the capacity of blood sera to promote acceptance of cholesterol (C) from Fu5AH hepatoma cells, esterification of delivered free C, and transfer of produced cholesteryl esters to apolipoprotein (apo) B-containing lipoproteins have been studied. Twenty male subjects with relatively high (>50 mg/dl, n = 10) and low (<50 mg/dl, n = 10) high density lipoprotein (HDL) C levels consumed for eight weeks red grape wine (0.3 g ethanol/kg body mass per day). Alcohol consumption reduced total C and low density lipoprotein C levels in both groups of subjects. Low HDL C subjects showed an increase in HDL C, apo AI, apo AII, and lipoprotein (Lp) AI particle levels after alcohol consumption. Alcohol did not affect free C efflux from the cells. However, after the following period of substitution of alcohol with an isocaloric amount of red grape juice, cellular C efflux markedly reduced. While lecithin:cholesterol acyltransferase (LCAT) activity increased during alcohol consumption only in subjects with low HDL C, high HDL C subjects showed a significant decrease in cholesteryl ester transfer protein (CETP) activity. At the same time, alcohol consumption reduced the endogenous C esterification rate and increased the transfer of endogenous cholesteryl esters to apo B-containing lipoproteins in both groups. Thus, alcohol consumption in moderate doses enhanced the anti-atherogenicity of the serum lipoprotein spectrum, supporting more effective C efflux from peripheral cells and transport of accepted C to apo B-containing lipoproteins. The effects of alcohol on the reverse cholesterol transport depend on the initial HDL C level.

Cerivastatin modulates antiatherogenic properties of high-density lipoproteins in patients with coronary heart disease and hyperlipidemia

The effects of cerivastatin on antiatherogenic properties of high-density lipoproteins were studied in patients with coronary heart disease and hyperlipidemia. Apart from hypolipidemic effects, cerivastatin changed the phospholipid composition of high-density lipoproteins and improved their cholesterol-acceptor properties. This effect was most pronounced in the serum from patients with low content of high-density lipoprotein cholesterol. These data indicate that cerivastatin modulates antiatherogenic properties of high-density lipoproteins.

[High-density lipoproteins in cholesterosis of the gall bladder]

The composition of serum high-density lipoproteins (HDL) was studied in 64 patients with polypous cholesterosis (PC). The spectrum of serum lipids in patients with PC was characterized by the lower concentrations of HDL cholesterol (42.0 +/- 2.5 mg/dl; p < 0.05) and higher concentrations of low-density lipoproteins (LDL) cholesterol (169.9 +/- 6.9 mg/dl; p < 0.01) than those in the controls. The decreased HDL cholesterol, or hypoalphacholesterolemia was associated with quantitative changes in HDL phospholipids (PL) (66.48 +/- 3.4; p < 0.01) and with changes in the composition of individual PL by lowering the proportion of lecithin (47.13 +/- 2.19 mg/dl; p < 0.01). It may be suggested that the lower amount of HDL cholesterol is caused by the decreased HDL acception of free cholesterol from the peripheral cell membranes due to the impaired complexation of PL with free cholesterol and associated the altered PL composition of the superficial monolayer of a lipoprotein particle. At the same time the physicochemical changes in Hdl superficial layer are a cause of abnormal free cholesterol esterification and the impaired plunge of esterified cholesterol into the nucleus of a HDL particle, which facilitates the conversion of HDL to LDL and may explain elevated LDL levels in cholesterosis. The findings suggest that serum lipids are involved in the development of cholesterosis.

[The lipid-protein indices of the blood cholesterol transport system in systemic lupus erythematosus]

AIM

To assess parameters of blood cholesterol lipid-protein spectrum and characteristics of blood cholesterol (C) transport system in patients with systemic lupus erythematosus (SLE).

MATERIALS AND METHODS

Lipid-protein blood spectrum was studied in 60 patients (45 females and 15 males) with verified SLE aged 15-44 years (mean age 28.9 +/- 8.1 years). The duration of the disease varied from 2 months to 28 years (mean 8.6 +/- 6.6 years). SLE course and activity were defined according to V. A. Nasonova's classification. The control patients (35 healthy subjects) were matched by age (30.0 +/- 6.1 years) and gender (27 females and 8 males).

RESULTS

Elevated levels of C and C of low-density lipoproteins (LDLP), triglycerides (TG) were found in 35% and 30% of patients, respectively. C of high-density lipoproteins (HDLP) was low in 32% of patients. HDLP phospholipids were also subnormal, their proportion changed: concentrations of phosphatidylcholine were low, those of lisophosphatidylcholine, sphingomyelin, diethanolamine, cardiolipin were higher than in the controls. TG and proportion apo/B/AI were higher, content of HDLP components low in patients with the disease duration up to 5 years. Patients with highly and moderately active SLE had high levels of TG, apo/B, apo/B/apo/AI, low levels of HDLP C, apo/AI and HDLP phospholipids.

CONCLUSION

Marked dyslipidemias were detected in 1/3 of SLE patients. Cholesterol transport changes arise at early SLE stages. Alterations in the blood lipid-protein spectrum appeared more pronounced and atherogenic in maximal SLE activity. Quantitative and qualitative shifts in HDLP composition induce changes in antiatherogenic properties of relevant lipoproteins in SLE patients.

[The characteristics of the blood lipid transport system in the disabled with lost lower extremities]

A comparative analysis of major blood lipoprotein values in 108 males aged 16-65 years with lower limbs amputations has shown a higher level of triglycerides (TG) and a reduced level of high density lipoprotein cholesterol (HDL C) in them than in control males with normal limbs. In the subgroup of patients who had undergone the amputation as a result of obliterative arterial disease, the TG level was the highest while HDL C the lowest; moreover, these values appeared to be the same as in the age-matched subgroup of patients with manifestations of atherosclerosis. In the subgroup of older men with posttraumatic lower limb amputations (aged 40-59 years) the TG and HDL C levels did not differ from the corresponding parameters in age-matched subgroup of healthy subjects, whereas young amputees (17-39 years) had the increased blood TG concentration and reduced level of HDL C and apolipoprotein AI. The conclusion is made: disability following limb amputation accompanied by restricted mobility, inadequate physical static efforts as well as by chronic psychological stress seem especially dangerous for young invalids because of associated lipoprotein profile changes which can be regarded as highly atherogenic.

Some aspects of perfluorochemical emulsion's interaction with blood

FDC/FTPA (7:3) emulsions stabilized by procsanol (Emulsion 1) and by procsanol with yolk phospholipids (Emulsion 2) were incubated with the donor plasma. After the incubation during 6 hours of Emulsions 1 and 2 with plasma the 36% and 50% decrease of the cholesterol content in plasma was found. Analysis of the lipid content of lipoproteins after the Emulsion 2 administration to rats (2.5 ml/100 g of weight) revealed the 50% decrease of the cholesterol amount in the HDL fraction at 3 and 24 hours posttransfusion. The ratio cholesterol/total phospholipids in the erythrocyte membrane diminished up to 50% as well. The equal degree of the cholesterol adsorption by emulsion from plasma, HDL of rats and erythrocyte membrane is an evidence of nonspecific interaction of PFC particles with the blood components containing cholesterol.

[Possible relationship between polyunsaturated fatty acids and signs of left ventricle hypertrophy]

In aborigines from the costal and continental areas of Chukotka who differ in dietary polyunsaturated fatty acid (PFA) n-3 intake, specific features of the composition of fatty acids in cell membranes were revealed in a model of erythrocytes: the costal inhabitants showed a higher proportion of PFA n-3 mainly through eicosapentaenic acid and lower proportion of major PFA n-6. With this, plasma lipoprotein lipids in whose composition the acids transported to the cell membranes displayed the similar regularities in changes in fatty acid composition. Only a far larger portion of eicosapentaenic acid in the cell membranes from the costal inhabitants than from the continental inhabitants was associated with greater mass of the left ventricular myocardium. It was concluded that transport of lipids containing high PFA n-3 in the composition of lipoproteins to the cell membranes caused an increase of the acids in them and, evidently, a change in physicochemical and, therefore, functional properties of cells.

[Platelet aggregation and plasma lipid spectrum in patients with myocardial infarct developing on the background of first-time appearing angina pectoris]

Patients with myocardial infarction in the presence of first angina pectoris have been found to display less platelet aggregability in the acute period of the disease than those with recurrent myocardial infarction, which is associated with a lower incidence of postinfarction complications and smaller plasma triglyceride levels. The changes observed in plasma lipid concentrations and platelet aggregation in different periods of the disease have been shown to be similar to those seen in patients with myocardial infarction concurrent with sustained angina.

[Comparative analysis of the lipid-protein spectrum of lipoproteins and fatty acid composition of lipids in plasma and erythrocytes of native populations of Chukotka and Moscow]

A lower content of total cholesterol, triglycerides, cholesterol of low density lipoproteins (LDL) and apo B as well as a higher content of cholesterol in high density lipoproteins (HDL) were found in coast and continental Chuckchee land inhabitants as compared with moscowites, which are dissimilar in consumption of polyunsaturated fatty acids n-3. At the same time, the lower content of total cholesterol, LDL cholesterol and higher concentration of HDL cholesterol were detected in blood plasma of coast inhabitants as compared with continental residents of the Chuckchee land, while content of apo B and triglycerides was similar. Concentration of apoA-I was the same in all three groups of the persons examined. The diet of coast Chuchkchee land inhabitants, involving the higher level of unsaturated fatty acids n-3, resulted in the higher ratio between HDL cholesterol and apoA-I, in the higher part of unsaturated fatty acids n-3 in blood plasma lipids (phospholipids and cholesterol esters) and erythrocytes; it led to a relative increase of sphingomyelin and phosphatidyl-ethanolamine and to a decrease of phosphatidylcholine in HDL subfractions. The data obtained suggest that the diet, enriched with polyunsaturated fatty acids n-3, exhibited the generalized effect on fatty acid composition of a number of cell membranes and, hence, on their functions.

[Changes in phospholipid composition of high density lipoproteins in children as a possible precursor of the development of ischemic heart disease]

The proportion of apoprotein-AI (apo-AI) phospholipids (PL) and HDLP phospholipid spectrum were determined in addition to principal coronary risk factors; cholesterol (CS), triglycerides (TG) and high-density lipoprotein (HDLP) CS, in high-risk children, whose parents had survived myocardial infarction at a young age, and also in children with vegetovascular dystonia and a control group. It is demonstrated that children with relatively low percentage of lecithin in HDLP, in the absence of changes in CS, TG, apo-B and apo-AI, and HDLP CS, could be found in all the examined groups, and were particularly numerous in the high-risk group. Correlations coefficients for the HDLP PL percentage in the father-child, mother-child and father-mother pairs were estimated, revealing a positive correlation with respect to lecithin in these pairs, an evidence of the contribution of the general familial environment to the variability of the parameter in question in the examined groups. Different correlations were demonstrated between lecithin/sphingomyelin and lecithin/kephalin ratios in boys and girls from the control and high-risk groups.

[Effect of essential phospholipids on the lipid spectrum of blood plasma and the aggregative capacity of thrombocytes in patients with ischemic heart disease]

A study of the effect of essentiale-forte in myocardial infarction patients demonstrated favorable shifts in plasma lipid spectrum and ADF-induced platelet aggregation.

[Activity of main enzyme reactions of lipoprotein metabolism in the plasma of patients with ischemic heart disease]

Evaluation of activity of main enzymatic systems involved in metabolism of lipoproteins, lipids and apoproteins in blood plasma of patients with heart ischemic disease, demonstrated that dissimilar alterations occurred in activity of the enzymatic systems responsible for transformation of lipoproteins in blood plasma. These alterations appear to be of great importance in the course of atherogenous impairments of lipoprotein metabolism found in the patients even in absence of distinct hyperlipidemia.

[Characteristics of fatty acid composition of phosphatidyl cholines and sphingomyelins of low-density lipoproteins in the plasma of native inhabitants of Chukotka]

Contents of cholesterol, triglycerides, high density lipoproteins (HDL) cholesterol as well as phospholipid and fatty acid compositions of phosphatidyl cholines and sphingomyelins in low density lipoproteins (LDL) were studied in blood plasma of Chukot aborigenes--Eskimos as compared with Moscow inhabitants. In Eskimos content of HDL cholesterol was higher but concentration of cholesterol and triglycerides was lower in blood plasma. In LDL concentration of sphingomyelins was increased and fatty acid composition of phosphatidyl cholines and sphingomyelins was altered where amount of polyunsaturated fatty acids was elevated (20:5 + 22:5 + 22:6). The specific characteristics of the LDL phospholipids observed in Eskimos might be responsible for the higher liquid properties of the surface monolayer in the lipoproteins; this alteration might be important for the lipoprotein properties and transformation as well as for the properties of membrane-bound enzymes, for synthesis of thromboxane and prostacyclins.

[Various reasons for changes in the phospholipid composition of high density lipoproteins in hypoalphacholesterolemia]

In men without any symptoms of ischemic heart disease, living in two different geographical zones (Moscow and Chuckchee land) low level of high density lipoprotein (HDL) cholesterol was accompanied by alterations in phospholipid composition of HDL2 and HDL3: decrease in the ration of lecithin and increase in sphingomyelin and kephalin content. The alteration in the phospholipid composition of these two HDL subclasses occurred simultaneously with changes in fatty acid composition of HDL lecithin: decrease in the ratio of linoleic acid as well as in stearic and arachidonic or eucosepentaenic acids. At the same time, phospholipid composition of the HDL subclasses was dissimilar in men and women without any symptoms of ischemic heart disease. Role of alterations in the fatty acid composition of phosphatide acid as well as effect of hormones on alterations in the phospholipid composition of HDL in hypoalphacholesterolemia are discussed.

[Esterifying activity of the plasma in patients with ischemic heart disease]

An esterifying activity of blood plasma (lecithin-cholesterol-acyl transferase, LCAT) was decreased in men with ischemic heart disease (IHD) and coronary atherosclerosis as compared with patients without any symptoms of IHD; the decrease of the activity was most distinct in patients with low level of cholesterol in high density lipoproteins (HDL) and with hyperlipidemia. In these patients phospholipid composition of HDL subfractions was altered: a decrease in the lecithin ratio, increase in the content of sphingomyelin and corresponding decrease in the ratio lecithin/sphingomyelin. Decrease in content of HDL cholesterol and in concentration of apo A-I in blood, plasma, alterations in phospholipid composition of HDL subfractions and in the rate of fatty acids unsaturation of HDL phospholipids in the patients with IHD were considered as factors responsible for the decrease of LCAT activity, which may aggravate the atherosclerotic impairment of arteries.

[Changes in the indices affecting the phospholipid structure of high density lipoprotein subfractions in ischemic heart disease]

As the alpha-cholesterol concentration decreased in blood plasma of healthy men, relative content of oleic and linoleic acids was also decreased in phospholipids of HDL2 subfraction without any alterations in HDL3 fraction. In the patients with ischemic heart disease content of linoleic acid was lower in the phospholipids and the ratio free cholesterol (HDL2 phospholipids was higher as compared with the group of healthy persons exhibiting the similar low content of cholesterol in HDL. The molar ratio free cholesterol) phospholipids was higher in the HDL3 fraction of the patients as compared with healthy persons, however composition of fatty acids was unaltered in the phospholipids Activity of lecithine cholesterol acyltransferase was lower in the patients as compared with healthy persons exhibiting the same content of cholesterol in HDL. Administration of heparin into the patients was responsible for an increase in the level of unsaturated phospholipids in HDL2 fraction (while they decreased in VLDL/as well as for a decrease in the ratio cholesterol/phospholipids. The data obtained suggest that alterations in the physico-chemical properties of the fraction studied might affect the antiatherogenic characteristics of HDL.

[Apoprotein A-1 in high-density lipoprotein subfractions and lecithin-cholesterol-acyltransferase activity in hyperalphacholesterinemia]

Content of apolipoprotein (apo A-I) was studied in subfractions of high density lipoproteins (HDL) using quantitative "rocket" immunoelectrophoresis in two groups of men with the level of LPHD cholesterol within 70 mg/dl (27 patients) and above 70 mg/dl (15 patients). An increase in content of cholesterol from HDL2 subfraction and activation of lecithine-cholesterol acyltransferase in hyper-alpha-cholesterolemia (hyper-alpha-lipoproteinemia) were mainly due to elevation in both absolute amount of apo A-I containing in HDL2 of blood plasma and in relative part of apo A-I in HDL2 of blood plasma and in relative part of apo A-I in HDL2. But contrary to the observation, content of apo A-I from HDL3 subfraction was decreased in the impairment. In aggrement with the modern hypothesis on the antiatherogenic nature of hyper-alpha-lipoproteinemia, the impairment is related to intensification of the cholesterol-acceptor function of HDL due to the activating effect of apolipoprotein A-I (content of which is increased in HDL2) on lecithine-cholesterol acyltransferase in vivo.

[Fatty acid makeup of the high-density lipoproteins in hyperalphalipoproteinemia]

An increase in the ratio of free cholesterol/phospholipids as well as in proportional content of oleic and linoleic acids were observed in lecithins of high density lipoproteins (HDL) from the 409-59 years old patients with hyper-alpha-lipoproteinemia. Activity of lecithine-cholesterol acyltransferase was also increased in blood plasma while the HDL cholesterol content increased. The data obtained suggest alterations in physicochemical properties of HDL and their effect on lecithine-cholesterol acyltransferase activity under conditions of hyper-alpha-lipoproteinemia.

[Collagen metabolism indices, and plasma concentrations of lipids, cyclic 3',5'-AMP, and certain hormones in 40-59-year-old men]

Concentrations of protein-bound hydroxyprolin, free hydroxyproline, cholesterol, alpha-cholesterol, triglycerides, testosterone, estradiol, insuline and 3',5'-cAMP were estimated in blood plasma of 40-59 years old men. The persons thus examined were divided into three groups depending on the content of protein-bound hydroxyproline. Only in blood plasma of persons with low concentration of the protein-bound hydroxyproline a direct correlation was found between cAMP and testosterone, cAMP and alpha-cholesterol, between cAMP and the ratio of the cholesterol from atherogenous lipoproteins to the cholesterol from alpha-lipoproteins, as well as reciprocal correlation--between cAMP and insulin. The increase of protein-bound hydroxyproline concentration and the decrease of cAMP content in blood plasma might be related to proliferation of smooth muscle cells in the vessel wall, dependent, first, on alteration in the ratio of lipoproteins of various density in blood plasma and, second, on alteration in the hormone concentration in blood and tissues.

[Lecithin-cholesterol acyltransferase activity and lipid composition of high density lipoprotein subfractions in hyperalphalipoproteinemia]

In blood plasma of men activity of lecithin-cholesterol acyl transferase /LCAT/ was elevated when the cholesterol concentration was increased in the fraction of high density lipoproteins /HDL/; the enzymatic activity was evaluated by the rate of 3H-cholesterol esterification in endogenous HDL. The phenomenon observed was accompanied by an increase in content of HDL2 subfraction: The content of free cholesterol was found to increase in the HDL2 fraction obtained from persons with hyper-alpha-lipoproteinemia. Analysis of the data obtained showed that LCAT activity was preferentially dependent on HDL3 cholesterol concentration in persons with low and middle content of HDL cholesterol, and--on HDL2 cholesterol concentration in patients with hyper-alpha-lipoproteinemia.

[Effect of cortisol on adenylate cyclase and 3',5'-AMP phosphodiesterase activity and 3',5'-AMP concentration in tissues and biological fluids in experimental atherosclerosis]

Administration of hydrocortisone into healthy rabbits activated adenilate cyclase and phosphodiesterase in liver tissue; activity of the enzymes was normalized within 5 days after the treatment. The hormone, administered into animals with experimental cholesterol-induced atherosclerosis, caused an activation of adenilate cyclase and inhibition of phosphodiesterase; due to the phenomenon more distinct and long-term increase in cAMP concentration was observed in kidney, liver and fatty tissues. Concentration of cAMP exceeded considerably its initial content in the tissues within 5 days after the hydrocortisone administration. Hydrocortisone inhibited the adenilate cyclase system activity in adrenal cortex of experimental and control animals at early period of the experiment. In health rabbits content of cAMP was increased in adrenal cortex within 5 days after the hormone administration. As the similar effect was not found in animals with experimental atherosclerosis these data suggest that the hypophysis-adrenal cortex system under the experimental conditions studied was inhibited.

[Effect of cortisol on the state of adenyl cyclase system in rabbits]

Content of 3',5'-cycloAMP was estimated in rabbit blood plasma and urine; activities of adenylcyclase and phosphodiesterase were determined in liver tissue, adipose tissue and adrenal glands within 5, 24 and 48 hrs after hydrocortisone administration. Concentration of 3',5'-cycloAMP was found to be increased 4-6-fold in plasma and urine after the hormone administration. Cortisol was shown to increase also the activity of adenylcyclase and phosphodiesterase in liver tissue within 5 hrs and in adipose tissue--within 24 hrs and 48 hrs after the administration. In adrenal glands hydrocortisone caused an inhibitory effect on the adenylcyclase activity at early steps of the experiment.

[Adenyl cyclase activity in the tissues and excretion of cyclic adenosine monophosphate in experimental arteriosclerosis]

The activity of adenylcyclase in the tissues and the elimination of 3',5'-AMP with urine were studied in rabbits and rats with experimentally induced atherosclerosis. The relationship between the concentration of steroid hormones and the activity of adenylcyclase in the adrenals was studied after varying periods of atherogenic diets. The activity of adenylcyclase was shown to decrease in the liver and the adrenal glands, as well as the concentration of corticosterone in the adrenals and the urine excretion of 3',5'-AMP, when the animals were kept on the atherogenic diet for long periods of time. No changes in the activity of adenylcyclase were noted in the lipid tissues of the animals with atherosclerosis. The concentration of the steroid hormones in the animals with experimental atherosclerosis was directly dependent on the activity of adenylcyclase in the tissues and the urine excretion of 3',5'-AMP. The administration of Cortisole resulted in a sharp increase of 3',5'-AMP excretion and an activation of adenylcyclase in the liver and lipid tissues of both normal animals, and those kept on an atherogenic diet.