scholarly journals Quantification of human serum paraoxonase by enzyme-linked immunoassay: population differences in protein concentrations

1994 ◽  
Vol 304 (2) ◽  
pp. 549-554 ◽  
Author(s):  
M C Blatter Garin ◽  
C Abbott ◽  
S Messmer ◽  
M Mackness ◽  
P Durrington ◽  
...  
Keyword(s):  
Particle Number ◽  
Physiological Function ◽  
Serum Levels ◽  
Enzymic Activity ◽  
High Density Lipoproteins ◽  
Serum Concentrations ◽  
Apolipoprotein A ◽  
Coefficients Of Variation ◽  
Serum Paraoxonase ◽  
Two Populations

Paraoxonase is a serum protein bound to high-density lipoproteins (HDLs). The physiological function of the enzyme is unknown, but a role in lipid metabolism has been postulated. To date, studies of the protein have had to rely on measurements of enzyme activity with various substrates. We have developed a highly specific, competitive e.l.i.s.a. using a previously characterized monoclonal antibody. The assay can detect 20 ng of paraoxonase with a working range of 75-600 ng. Intra- and interassay coefficients of variation were 6.5 and 7.9% respectively. Serum concentrations of paraoxonase in healthy subjects from Geneva and Manchester ranged from 25 to 118 micrograms/ml. There were significant differences in mean concentrations between the two groups (Geneva, 79.3 +/- 18.7 micrograms/ml; Manchester, 59.9 +/- 24.1 micrograms/ml: P < 0.001), differences also apparent when subjects were compared according to paraoxonase phenotype. These appeared to be largely a consequence of differences in apolipoprotein A-I concentrations between the two populations, suggesting that HDL particle number may be important in determining serum levels of paraoxonase. Paraoxonase specific activities were also significantly different between the two groups of subjects (Geneva, 2.08 +/- 0.96 units/mg; Manchester, 3.08 +/- 1.73 units/mg: P < 0.001), which may reflect differences in HDL particle composition. The e.l.i.s.a. should furnish the necessary complement to studies of paraoxonase enzymic activity and has already provided evidence for differences with respect to serum levels of the protein both between populations and between phenotypes within populations.

Abstract 631: Proteomic Characterization of Apolipoprotein A-II Defined Subfractions of Human High Density Lipoproteins

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Scott E Street ◽  
John T Melchior ◽  
Amy S Shah ◽  
W. S Davidson
Keyword(s):  
Physiological Function ◽  
Critical Role ◽  
Size Composition ◽  
High Density ◽  
Lipid Homeostasis ◽  
High Density Lipoproteins ◽  
Phospholipid Content ◽  
Hdl Function ◽  
Apolipoprotein A

High-density lipoproteins (HDL) play a critical role in lipid transport and vascular lipid homeostasis. HDL is heterogeneous, with particles varying in size, composition, and functionality. Proteomic studies have shown that HDL can host as many as 94 different proteins which can segregate into distinct subclasses. The two major apolipoproteins (apo)A-I and apoA-II account for 70% and 15-20%, respectively of HDL total protein. We hypothesized that the presence or absence of apoA-II can affect the binding of other proteins thus influencing HDL function. Immunoaffinity chromatography was used to isolate particles containing both apoA-I and apoA-II (LpA-I/LpA-II) and those with apoA-I with no apoA-II (LpA-I). These were isolated from both i ) total HDL isolated by ultracentrifugation (UC) and ii ) directly from plasma. The proteomic fingerprint of each population was determined by mass spectrometry. Within both populations, 54 total proteins were identified in UC isolated HDL compared to 98 proteins in particles isolated directly from plasma. In the UC isolated HDL, LpA-I/A-II particles contained 39 proteins compared to LpA-I particles which contained about 30. Interestingly, the opposite was true in particles isolated from plasma where upwards of 77 proteins on LpA-I/A-II particles were identified compared to LpA-I particles where 98 proteins were identified. Limited tryptic digestion experiments showed that LpA-I/A-II were more prone to proteolysis compared to LpA-I. Additionally, we found that LpA-I/A-II exhibited an increased capacity to efflux cholesterol from cultured macrophages (normalized by phospholipid content) suggesting a protein mediated difference in HDL functionality. Taken together, these results suggest the proteomic fingerprint of HDL subpopulations is heavily influenced by the method of isolation and that the proteomic pattern on HDL influences the physiological function of the particle.

scholarly journals Apolipoprotein A-I stimulates secretion of insulin and matrix metalloproteinases by islets of Langerhans

2018 ◽  
Vol 64 (2) ◽  
pp. 195-200 ◽  
Author(s):  
I.F. Usynin ◽  
O.N. Poteryaeva ◽  
G.S. Russkikh ◽  
A.V. Zubova ◽  
K.Yu. Boiko ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Matrix Metalloproteinases ◽  
Islets Of Langerhans ◽  
Fold Increase ◽  
Serum Levels ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Apo B ◽  
Apolipoprotein A

The development of type 2 diabetes mellitus (DM2) is accompanied by disturbances in lipid metabolism. These include the increase in serum levels of atherogenic fractions of very low-density (VLDL) and low-density lipoproteins (LDL), total cholesterol, triglycerides and apo B. In contrast, the level of antiatherogenic high density lipoproteins (HDL) and the content of apolipoprotein A-I (apoA-I) decreased. To study the effect of the observed metabolic changes on insulin secretion in vitro, we used the islets of Langerhans isolated from the rat pancreas. It has been found that incubation of the islets in the presence of serum of the obese patients and patients with decompensated DM2 leads to a decrease in insulin secretion by 2.4 and 5.0 times, respectively. On the contrary, the addition of HDL to the incubation medium increased the insulin secretion by 3.4 times. A similar effect was observed in the presence of apoA-I, the main protein component of HDL. In the presence of apoA-I, the extracellular activity of matrix metalloproteinases (MMPs) demonstrated a 10-fold increase. The addition of LDL and VLDL to the islets did not change the secretion of insulin and activity of MMP. Our results testify to the important role of HDL and apoA-I in regulation of the insulin secretion by b-cells and the activity of MMPs in the islets of Langerhans.

Measurement of Potato Steroidal Alkaloids in Human Serum and Saliva by Radioimmunoassay

1985 ◽  
Vol 4 (5) ◽  
pp. 503-512 ◽  
Author(s):  
M.H. Harvey ◽  
B.A. Morris ◽  
M. McMillan ◽  
V. Marks
Keyword(s):  
Human Serum ◽  
Total Alkaloid ◽  
Serum Levels ◽  
Serum Concentrations ◽  
Steroidal Alkaloids ◽  
Potato Glycoalkaloids ◽  
High Concentrations ◽  
The Uk ◽  
Two Populations

1 Radioimmunoassay methods are described for measuring potentially toxic potato glycoalkaloids and the aglycone solanidine in human serum and saliva. 2 Solanidine and total alkaloid concentrations in serum and saliva during the summer are given for a group of subjects from the UK and a group from Sweden. Serum concentrations ranged from 3.2 to > 125 nmol/l for total alkaloid and 2.5 to 92.5 nmol/l for solanidine and were comparable in the two populations. Salivary total alkaloid concentrations were only about 10% of serum values. Salivary solanidine concentrations did not exceed 20% of the serum levels. Good correlation was found between serum and salivary alkaloid concentrations ( r = 0.734, for solanidine; r = 0.892 for total alkaloid). 3 Serum and salivary alkaloid concentrations were significantly raised in a group of Swedish subjects eating potatoes containing unusually high concentrations of alkaloids when compared with those in a group of subjects eating their normal diets.

Changes in growth rate and thyroid- and sex-hormones blood levels in rats under sub-chronic lithium treatment

2006 ◽  
Vol 25 (5) ◽  
pp. 243-250 ◽  
Author(s):  
M S Allagui ◽  
N Hfaiedh ◽  
C Vincent ◽  
F Guermazi ◽  
J-C Murat ◽  
...  
Keyword(s):  
Growth Rate ◽  
Lithium Treatment ◽  
Lithium Carbonate ◽  
Serum Levels ◽  
Antagonistic Effect ◽  
Blood Levels ◽  
Vaginal Mucosa ◽  
Dependent Manner ◽  
Serum Concentrations ◽  
Dose Dependent

Lithium therapy, mainly used in curing some psychiatric diseases, is responsible for numerous undesirable side effects. The present study is a contribution to the understanding of the pathophysiological mechanisms underlying lithium toxicity. Male and female mature rats were divided into three batches and fed commercial pellets: one batch was the control and the second and third batches were given 2 g (Li1) and 4 g (Li2) of lithium carbonate/kg of food/day, respectively. After 7, 14, 21 and 28 days, serum levels of free tri-iodothyronine (FT3), thyroxine (FT4), testosterone and estradiol were measured. Attention was also paid to growth rate and a histological examination of testes or vaginal mucosa was carried out. In treated rats, a dose-dependent loss of appetite and a decrease in growth rate were observed, together with symptoms of polydypsia, polyuria and diarrhea. Lithium serum concentrations increased from 0.44 mM (day 7) to 1.34 mM (day 28) in Li1 rats and from 0.66 to 1.45 mM (day 14) in Li2 rats. Li2 treatment induced a high mortality after 14 days, reaching 50-60% in female and male animals. From these data, the LD50 (14 days Li2 chronic treatment) was calculated to be about 0.3 g/day per kilogram of animal, leading to Li serum concentrations of about 1.4 mM. A significant decrease of FT3 and FT4 was observed in treated rats. This effect appeared immediately for the highest dose and was more pronounced for FT3, resulting in an increase of the FT4/FT3 ratio. In males, testosterone decreased and spermatogenesis was stopped. Conversely, in females, estradiol increased in a dose-dependent manner as the animals were blocked in the diestrus phase at day 28. This finding supports a possible antagonistic effect of lithium on the estradiol receptors.

scholarly journals Importance of Apolipoprotein A-I and A-II Composition in HDL and Its Potential for Studying COVID-19 and SARS-CoV-2

Medicines ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 38
Author(s):  
Kyung-Hyun Cho
Keyword(s):  
Antiviral Activity ◽  
High Density ◽  
High Density Lipoproteins ◽  
Potent Antiviral Activity ◽  
Apolipoprotein A ◽  
Putative Role

The composition and properties of apolipoprotein (apo) A-I and apoA-II in high-density lipoproteins (HDL) might be critical to SARS-CoV-2 infection via SR-BI and antiviral activity against COVID-19. HDL containing native apoA-I showed potent antiviral activity, while HDL containing glycated apoA-I or other apolipoproteins did not. However, there has been no report to elucidate the putative role of apoA-II in the antiviral activity of HDL.

Dietary and serum vitamin D and preeclampsia risk in Chinese pregnant women: a matched case–control study

2021 ◽  
pp. 1-26
Author(s):  
Xue-min Huang ◽  
Yan-hua Liu ◽  
Han Zhang ◽  
Yuan Cao ◽  
Wei-feng Dou ◽  
...  
Keyword(s):  
Vitamin D ◽  
Dietary Intake ◽  
Pregnant Women ◽  
Case Control Study ◽  
Serum Levels ◽  
Case Control ◽  
Serum Concentrations ◽  
Matched Case ◽  
Matched Case Control Study ◽  
Control Study

Abstract The effect of vitamin D (VD) on the risk of preeclampsia (PE) is uncertain. Few of previous studies focused on the relationship between dietary VD intake and PE risk. Therefore, we conducted this 1:1 matched case-control study to explore the association of dietary VD intake and serum VD concentrations with PE risk in Chinese pregnant women. A total of 440 pairs of participants were recruited during March 2016 to June 2019. Dietary information was obtained using a 78-item semi-quantitative food frequency questionnaire. Serum concentrations of 25(OH)D2 and 25(OH)D3 were measured by liquid chromatography–tandem mass spectrometry. Multivariate conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Restricted cubic splines (RCS) were plotted to evaluate the dose-response relationship of dietary VD intake and serum VD concentrations with PE risk. Compared with the lowest quartile, the ORs of the highest quartile were 0.45 (95%CI: 0.29-0.71, Ptrend = 0.001) for VD dietary intake and 0.26 (95%CI: 0.11-0.60, Ptrend = 0.003) for serum levels after adjusting for confounders. In addition, the RCS analysis suggested a reverse J-shaped relationship between dietary VD intake and PE risk (P-nonlinearity = 0.02). A similar association was also found between serum concentrations of total 25(OH)D and PE risk (P-nonlinearity = 0.02). In conclusion, this study provides evidence that higher dietary intake and serum levels of VD are associated with the lower risk of PE in Chinese pregnant women.

scholarly journals The Effect of Bilateral Nephrectomy on Renalase and Catecholamines in Hemodialysis Patients

2021 ◽  
Vol 18 (12) ◽  
pp. 6282
Author(s):  
Magda Wiśniewska ◽  
Natalia Serwin ◽  
Violetta Dziedziejko ◽  
Małgorzata Marchelek-Myśliwiec ◽  
Barbara Dołęgowska ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Plasma Concentrations ◽  
Serum Levels ◽  
Hemodialysis Patients ◽  
Pressure Regulation ◽  
Serum Concentrations ◽  
Monoamine Oxidase Activity ◽  
Normal Kidney ◽  
Bilateral Nephrectomy ◽  
Arterial Blood

Background/Aims: Renalase is an enzyme with monoamine oxidase activity that metabolizes catecholamines; therefore, it has a significant influence on arterial blood pressure regulation and the development of cardiovascular diseases. Renalase is mainly produced in the kidneys. Nephrectomy and hemodialysis (HD) may alter the production and metabolism of renalase. The aim of this study was to examine the effect of bilateral nephrectomy on renalase levels in the serum and erythrocytes of hemodialysis patients. Methods: This study included 27 hemodialysis patients post-bilateral nephrectomy, 46 hemodialysis patients without nephrectomy but with chronic kidney disease and anuria and 30 healthy subjects with normal kidney function. Renalase levels in the serum and erythrocytes were measured using an ELISA kit. Results: Serum concentrations of renalase were significantly higher in post-bilateral nephrectomy patients when compared with those of control subjects (101.1 ± 65.5 vs. 19.6 ± 5.0; p < 0.01). Additionally, renalase concentrations, calculated per gram of hemoglobin, were significantly higher in patients after bilateral nephrectomy in comparison with those of healthy subjects (994.9 ± 345.5 vs. 697.6 ± 273.4, p = 0.015). There were no statistically significant differences in plasma concentrations of noradrenaline or adrenaline. In contrast, the concentration of dopamine was significantly lower in post-nephrectomy patients when compared with those of healthy subjects (116.8 ± 147.7 vs. 440.9 ± 343.2, p < 0.01). Conclusions: Increased serum levels of renalase in post-bilateral nephrectomy hemodialysis patients are likely related to production in extra-renal organs as a result of changes in the cardiovascular system and hypertension.

scholarly journals Association of Serum Levels of Zinc, Copper, and Iron with Risk of Metabolic Syndrome

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 548
Author(s):  
Chia-Wen Lu ◽  
Yi-Chen Lee ◽  
Chia-Sheng Kuo ◽  
Chien-Hsieh Chiang ◽  
Hao-Hsiang Chang ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Metabolic Syndrome ◽  
Linear Models ◽  
Serum Zinc ◽  
Serum Levels ◽  
Least Square ◽  
Model Assessment ◽  
Serum Concentrations ◽  
Metabolic Factors ◽  
Homeostatic Model Assessment

The association between serum concentrations of zinc, copper, or iron and the risk of metabolic syndrome are inconclusive. Therefore, we conduct a case-control study to explore the relationship between serum levels of zinc, copper, or iron and metabolic syndrome as well as each metabolic factor and insulin resistance. We enrolled 1165 adults, aged ≥ 40 (65.8 ± 10) years in a hospital-based population to compare the serum levels of zinc, copper, and iron between subjects with and without metabolic syndrome by using multivariate logistic regression analyses. The least square means were computed by general linear models to compare serum concentrations of zinc, copper, and iron in relation to the number of metabolic factors. The mean serum concentrations of zinc, copper, and iron were 941.91 ± 333.63 μg/L, 1043.45 ± 306.36 μg/L, and 1246.83 ± 538.13 μg/L, respectively. The odds ratios (ORs) of metabolic syndrome for the highest versus the lowest quartile were 5.83 (95% CI: 3.35–10.12; p for trend < 0.001) for zinc, 2.02 (95% CI: 1.25–3.25; p for trend: 0.013) for copper, and 2.11 (95% CI: 1.24–3.62; p for trend: 0.021) for iron after adjusting for age, sex, personal habits, body mass index, and homeostatic model assessment insulin resistance. Additionally, the serum zinc, copper, and iron concentrations increased as the number of metabolic factors rose (p for trend < 0.001). This was the first study to clearly demonstrate that higher serum levels of zinc, copper, and iron were associated with the risk of metabolic syndrome and the number of metabolic factors independent of BMI and insulin resistance.

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