Distribution Of Serum Lipoproteins Research Articles

Low IDL-B and high LDL-1 subfraction levels in serum of ALS patients

IntroductionConverging evidence highlights that lipid metabolism plays a key role in ALS pathophysiology. Dyslipidemia has been described in ALS patients and may be protective but peripheral lipoprotein subclasses have never been studied. Material and methodsWe collected sera from 30 ALS patients and 30 gender and age-matched controls. We analyzed 11 distinct lipoprotein subclasses by linear polyacrylamide gel electrophoresis (Lipoprint, Quantimetrix Corporation, USA). We also measured lipoprotein (a), apolipoprotein B, and apolipoprotein E levels. ResultsALS patients had significant higher total cholesterol, HDL-cholesterol, and LDL-cholesterol levels than controls (p<0.0001, p=0.0007, and p=0.0065, respectively). The LDL-1 subfraction concentration was higher (1.03±0.41 vs. 0.71±0.28mmol/L; p=0.0006) and the IDL-B subfraction lower (6.5±2% vs. 8.0±2%; p=0.001) in ALS patients than controls. DiscussionOur preliminary work confirmed the association between ALS and dyslipidemia. The low IDL-B levels may explain the hepatic steatosis frequently reported in ALS. The high levels of the cholesterol-rich LDL-1 subfraction is consistent with previously reported hypercholesterolemia. ConclusionThis study describes, for the first time, the distribution of serum lipoproteins in ALS patients, with low IDL-B and high LDL-1 subfraction level.

Amplified effect of taurine on PCB-induced hypercholesterolemia in rats.

The physiological functions of taurine such as membrane-stabilization, antioxidation, detoxification, osmoregulation, neuromodulation and brain-retinal development have been investigated in detail. Currently, we have been examining the hypercholesterolemic action of taurine in several conditions. In a previous study we reported that feeding a normal diet with taurine supplementation did not change the serum cholesterol levels, but in animals fed a high cholesterol diet, in which serum cholesterol significantly increased, taurine supplementation significantly reduced the cholesterol level11,19. This hypocholesterolemic action of taurine is explained by an increase in the activity of cholesterol 7 α-hydroxylase and also by the enhancement of fecal steroid excretion. Also, when the serum lipoprotein distribution was monitored by agarose-gel electrophoresis, the heavier very low density lipoprotein (VLDL), namely β-VLDL, significantly increased by feeding a high cholesterol diet. However, taurine repressed this increase and normalized the lipoprotein pattern. Many other investigators also examined the mechanism of hypercholesterolemia induced by feeding a high cholesterol diet, and demonstrated the elevation of both low density lipoprotein (LDL) and VLDL-cholesterol10,19.

Method for quantitating cholesterol in subfractions of serum lipoproteins separated by gradient gel electrophoresis.

Extensive heterogeneity in particle size distribution of serum lipoproteins of baboons was resolved by a procedure that combined Sudan black B prestaining, polyacrylamide gradient gel electrophoresis (GGE), and quantitative densitometry. Each densitometric scan represented a continuous distribution of the relative amount of cholesterol in a serum sample, as a function of the lipoprotein particle size. For analytical purposes, each scan was divided into 12 fractions, representing 12 particle size ranges. The relationship between the estimated cholesterol concentrations in the summed GGE/densitometric fractions corresponding to very low-density lipoproteins (VLDL) + low-density lipoproteins (LDL) and those corresponding to high-density lipoproteins (HDL) and concentrations measured by the heparin-Mn2+ precipitation/enzymatic procedure was linear over a broad range. However, a systematic overestimation of HDL cholesterol concentration and an underestimation of VLDL + LDL cholesterol concentration was apparent. Therefore, correction factors were developed for adjusting the estimates of VLDL + LDL and HDL cholesterol concentrations obtained by the GGE/densitometric method. This analytical method is rapid, repeatable, economical, and useful for genetic and dietary research in which cholesterol concentrations in multiple particle size ranges of lipoproteins must be measured in large numbers of samples. It also is adaptable to immunoblotting procedures for detecting the distribution of specific apolipoproteins among the size-resolved lipoproteins.

Chylomicra in the serum of postprandial steelhead trout ( Salmo gairdnerii)

1. 1. Postprandial effects on serum lipoprotein distribution were determined in juvenile steelhead trout ( Salmo gairdnerii). 2. 2. As many as eight lipoproteins were detected, including proteins of α, α 2 , and β mobility, as well as up to three discrete proteins with albumin-like mobility. 3. 3. Two and 4 hr after feeding, large electrophoretically-immobile lipoproteins, corresponding to chylomicra, were detected. 4. 4. Isolated d = 0.96 lipoproteins were 80% triacylglycerol; thus confirming the chylomicra-nature of these particles. 5. 5. The presence of triacylglycerol-rich chylomicra in the serum of trout suggests that exogenous lipid is, in part, transported to the body tissues of these animals in a manner similar to mammals.

Effects of three dietary fats on plasma lipids and lipoproteins in fasting and post-prandial humans after a short-term diet.

The effects of 3 dietary fats (olive oil, canbra oil and butter) on the fatty acids of blood lipids and on serum lipoproteins were compared in 6 healthy adult outpatients, after a 6-day normocaloric diet including 35% of the studied fat. Important, although incomplete, changes appeared in the fatty acid composition of the various serum lipids and in the composition and distribution of serum lipoproteins. These changes probably result from the degree of saturation of the fat ingested. Moreover, differences were observed among individual subjects. Genetic differences, which are important in clinical practice, are stressed in connection with risks of vascular diseases and hyperlipidemia and affect intestinal fat absorption and lipoprotein metabolism.

Effect of voluntary exercise and dietary protein levels on serum lipoprotein distributions and lecithin: cholesterol acyltransferase (LCAT) activity of mice.

The effect of voluntary exercise on serum lipoprotein distributions, lecitin:cholesterol acryltransferase (LCAT) activity and serum electrophoretic patterns of mice fed different levels of dietary protein were investigated. Serum cholesterol of all exercise groups (E) showed a lower value than that of the non-exercise groups (NE). Ratios of cholesteryl ester to serum total cholesterol tended to be higher in the exercise groups than in non-exercise groups. High density lipoprotein(HDL)-cholesterol/serum total cholesterol ratios and HDL-cholesterol/low density lipoprotein(LDL)-cholesterol ratios were increased by voluntary exercise. With regard to low density lipoprotein cholesterol levels, there were significant differences between 20% E and 20% NE groups, 4% NE groups, respectively. It was found that HDL fractions in serum lipoprotein patterns of exercise groups differed from those of non-exercise groups. This seemed to be prominent in low protein diet groups. LCAT acitivity showed decreasing values as dietary protein levels decreased and its activity was raised by voluntary exercise in all groups.

Serum lipoproteins in two species of phocids ( Phoca vitulina and Mirounga angustirostris) during alimentary lipemia

1. 1. Serum lipoprotein distributions of harbor seals ( Phoca vitulina) and elephant seals ( Mirounga angustirostris) during alimentary lipemia were measured by analytical ultracentrifugation. 2. 2. Lipid compositions and concentrations of the total VLDL, LDL, and HDL classes were also determined. During alimentary lipemia increased serum triglycerides were associated with concentration changes in the total VLDL class. A postprandial increase in HDL phospholipid was observed in one animal. 3. 3. Comparison of lipid concentration of the total VLDL class with the S° ∝ 20–400 data indicates that chylomicra are the principal triglyceride carriers during alimentary lipemia and that there are only slight changes among the S ∝ 20–400 lipoproteins. 4. 4. Electrophoretic analyses were carried out on sera obtained from elephant seals. Chylomicron and pre-beta bands were detected, but there was no discernible beta band. Consistent with the latter finding no S° ∝ 0–20 lipoproteins were observed in the analytical ultracentrifuge. 5. 5. These data are discussed in terms of the clearance of chylomicron remnants.

Distribution of serum lipoproteins of selected vertebrates

1. 1. Agarose gel electrophoresis was performed on the sera of thirty-six mammals, reptiles, amphibians, fish and birds, and the quantitative distribution of the lipoprotein classes in each animal was determined. 2. 2. Pig, opossum and garter snake sera seem to contain large amounts of low density lipoprotein, the lipoprotein class which is of primary interest in atherosclerosis research. These animals also have serum cholesterol values similar to humans. 3. 3. Agarose gel electrophoresis proved an excellent method for determining lipoprotein distributions, but the electrophoretic mobilities of the lipoproteins appear to be unsuitable for lipoprotein classification.

The distribution and composition of serum lipoproteins in the coelacanth ( Latimeria)

1. 1. The distribution of the serum lipoproteins has been determined in a specimen of the coelacanth, Latimeria. They have also been separated into the conventional density classes and their composition determined. 2. 2. In their composition the coelacanth lipoproteins differ from those of higher animals, but are similar to those found in the hagfish, Myxine glutinosa. This may be evidence that an evolutionary refinement of lipoprotein structure was taking place during the development of the more primitive fish.

The distribution and composition of serum lipoproteins in eighteen animals

1.1. The distribution of serum lipoproteins has been determined in eighteen species of mammals, five of birds and eleven reptiles and fish. The chemical composition of the lipoproteins has also been determined in eighteen of these species.2.2. There are differences in distribution and/or composition of the lipoproteins of these three classes, but the members of each class show a degree of similarity.3.3. Among the mammals, no animal could duplicate the pattern and composition of lipoproteins found in man, the most similar being those of the Old World monkeys.4.4. Although it has been possible to draw some conclusions about the development of lipoproteins in different animals, and on common aspects of their structure, it has not been possible to throw any light on the evolutionary origins of the serum lipoproteins.

Analysis of change in ultracentrifugal lipoprotein profiles following heparin and ethyl- p-chlorophenoxyiso-butyrate administration

Changes in human serum lipoprotein distribution following heparin and ethyl- p-chlorophenoxyisobutyrate administration in vivo are evaluated by application of a computerized technique for analysis of ultracentrifugal films. Flotation rate ranges within which concentration changes occur are delineated for the two agents.

Serum lipoprotein distribution, flotation rates and protein analysis.

AbstractFlotation rates of the major Sf 0舑12 lowdensity lipoprotein component in human serum may be calculated from ultracentrifuge data utilizing two computer programs. One program calculates a classical moving boundary uncorrected flotation rate by a best fit straight line for the points (1n xi, ३2ti). The other program permits erratum for concentration dependence and erratum to standard reference conditions. Preliminary application of these methods indicates significantly greater flotation rates in normal human females than in males for the 35舑49 year age group.The significance of interrelationships between the serum lipoprotein spectra, the serum lipids and the serum proteins is considered, resulting in the development of a revised method of measuring serum proteins by precision refractometry. The refractometric measurement is corrected in accordance with (any of various) lipid measurements in order to account for the contribution of lipoproteins to the total refractive increment. Such a technique, giving potentially a very accurate protein measurements, has application in screening studies involving abnormalities of both serum lipoprotein and serum protein metabolism.

Studies on the blood lipids and lipoproteins in thalassaemia and sickle cell anaemia

In Cooley's anaemia the serum lipid fraction, determined by chemical analysis, was found to be decreased. The lipoprotein distribution by paper electrophoresis showed a characteristic pattern with abnormally low alpha(1) fraction and high concentrations of the beta fractions. There is no relationship between age and serum lipoprotein distribution. A correlation was found between the electrophoretic pattern, liver function tests, and the E/C index. Similar changes but of lesser degree were found in sickle cell anaemia. Liver damage is thought to be the probable cause of the reduced alpha(1) fraction.

THE INFLUENCE OF GONADAL HORMONES ON SERUM LIPIDS AND LIPOPROTEINS: STUDIES IN NORMAL AND HYPOGONADAL SUBJECTS

Excerpt Clinicians have known for almost 200 years that the manifestations of coronary atherosclerosis are much more frequent in men than in women. Numerous autopsy studies have disclosed the disea...

Hyperlipoproteinemia

1. 1. The serum lipoproteins of cases of xanthoma tendinosum, xanthoma tuberosum, xanthelasma, the nephrotic syndrome, biliary cirrhosis, myxedema and “essential” hyperlipemia are compared with each other and with the normal serum lipoprotein distribution. 2. 2. The diagnosis of the nephrotic syndrome can almost always be made by the serum lipoprotein spectrum alone. 3. 3. The diagnosis of biliary cirrhosis can almost always be made by the serum lipoprotein spectrum alone. 4. 4. Xanthoma tuberosum and “essential” hyperlipemia can almost always be differentiated from the other conditions by means of the serum lipoproteins alone and usually patients with these conditions can be differentiated from each other by this test. 5. 5. Xanthoma tendinosum, xanthelasma and myxedema can be distinguished from the other conditions described here but the serum lipoprotein spectra in these cases are sufficiently similar to each other to make it difficult or impossible to make the differential diagnosis among them by the serum lipoproteins alone. 6. 6. It is suggested that the serum lipoprotein spectrum be considered the standard diagnostic feature of these illnesses rather than such nebulous criteria as turbidity of sera, or such non-distinguishing criteria as serum cholesterol determinations.