Search results for "Esteri"
showing 10 items of 220 documents
Fatty acid oxidation and related gene expression in heart depleted of carnitine by mildronate treatment in the rat.
2004
The metabolic and genic effects induced by a 20-fold lowering of carnitine content in the heart were studied in mildronate-treated rats. In the perfused heart, the proportion of palmitate taken up then oxidized was 5-10% lower, while the triacylglycerol (TAG) formation was 100% greater than in controls. The treatment was shown to increase the maximal capacity of heart homogenates to oxidize palmitate, the mRNA level of carnitine palmitoyltransferase I (CPT-I) isoforms, the specific activity of CPT-I in subsarcolemmal mitochondria and the total carnitine content of isolated mitochondria. Concomitantly, the increased mRNA expression of lipoprotein lipase, fatty acid translocase and enzymes of…
Higher Free Fatty Acid Uptake in Visceral Than in Abdominal Subcutaneous Fat Tissue in Men
2010
Visceral adipose tissue has been shown to have high lipolytic activity. The aim of this study was to examine whether free fatty acid (FFA) uptake into visceral adipose tissue is enhanced compared to abdominal subcutaneous tissue in vivo. Abdominal adipose tissue FFA uptake was measured using positron emission tomography (PET) and [F-18]-labeled 6-thia-hepta-decanoic acid ([F-18]FTHA) and fat masses using magnetic resonance imaging (MRI) in 18 healthy young adult males. We found that FFA uptake was 30% higher in visceral compared to subcutaneous adipose tissue (0.0025 +/- 0.0018 vs. 0.0020 +/- 0.0016 mu mol/g/min, P = 0.005). Visceral and subcutaneous adipose tissue FFA uptakes were strongly…
Vaccenic and elaidic acid equally esterify into triacylglycerols, but differently into phospholipids of fed rat liver cells.
2011
Elaidic acid (trans-9-C18:1 or trans-9) is assumed to exert atherogenic effects due to its double bond configuration. The possibility that trans-9 and vaccenic acid (trans-11-C18:1 or trans-11), its positional isomer, were biochemically equivalent and interchangeable compounds, was investigated by reference to their cis-isomers through esterification-related activities using rat liver cells and subcellular fractions. In hepatocytes, both trans-C18:1 were incorporated to the same extent in triacylglycerols, but trans-9 was more esterified than trans-11 into phospholipids (P < 0.05). Glycerol-3-phosphate acyltransferase activity in microsomes was lower with trans-11 than with trans-9, while t…
Retinas of the Diurnal RodentArvicanthis ansorgeiAre Highly Resistant to Experimentally Induced Stress and Degeneration
2011
International audience; PURPOSE. Environmentally induced stress plays a significant role in retinal degeneration and blindness both in animals and in humans. Among such sources of stress, phototoxicity is well studied and has been shown to lead to photoreceptor-specific loss in a number of species. However, the vast majority of studies have been conducted in nocturnal, albino rod-dominant rat and mouse strains, and the pertinence of such findings to human pathology and cone loss is debatable. The authors examined retinal vulnerability to damage in the diurnal murid rodent Arvicanthis ansorgei, a pigmented species with a large number of cones. METHODS. The authors used established protocols …
Liver and pancreatic fat content and metabolism in healthy monozygotic twins with discordant physical activity
2011
Background & Aims: Ectopic fat in muscle and liver is linked to obesity and type 2 diabetes. Recently, pancreatic lipid accumulation has also been associated with beta-cell dysfunction and reduced insulin production, leading to the development of type 2 diabetes. Physical exercise training has been shown to attenuate beta-cell dysfunction in patients, but little is known about its effects on pancreatic and hepatic fat accumulation. In this study, we validated in-vivo proton magnetic resonance spectroscopy ((1)H MRS) in pancreatic fat measurement with biochemical measurements in a pig model. Thereafter, the effects of increased physical activity on the amounts of pancreatic and liver fat…
Fatty liver in familial hypobetalipoproteinemia: triglyceride assembly into VLDL particles is affected by the extent of hepatic steatosis
2003
Familial hypobetalipoproteinemia (FHBL) subjects may develop fatty liver. Liver fat was assessed in 21 FHBL with six different apolipoprotein B (apoB) truncations (apoB-4 to apoB-89) and 14 controls by magnetic resonance spectroscopy (MRS). Liver fat percentages were 16.7 +/- 11.5 and 3.3 +/- 2.9 (mean +/- SD) (P = 0.001). Liver fat percentage was positively correlated with body mass index, waist circumference, and areas under the insulin curves of 2 h glucose tolerance tests, suggesting that obesity may affect the severity of liver fat accumulation in both groups. Despite 5-fold differences in liver fat percentage, mean values for obesity and insulin indexes were similar. Thus, for similar…
Hepatic steatosis is not due to impaired fatty acid oxidation capacities in C57BL/6J mice fed the conjugated trans-10,cis-12-isomer of linoleic acid.
2004
Decreased body fat mass and liver steatosis have been reported in mice fed diets containing the conjugated linoleic acid trans-10,cis-12-C18:2 (CLA2), but not in those fed diets containing cis-9,trans-11-C18:2 (CLA1). Because the decrease in fatty acid (FA) oxidation may cause fat accumulation, we questioned whether the effects of both CLAs on enzyme activities and mRNA expression were related to liver FA oxidation. To address this question, 7-wk-old male C57BL/6J mice were fed for 4 wk a diet supplemented with 1% CLA1, CLA2, or cis-9-C18:1 (control) esterified as triacylglycerols. In CLA2-fed mice, the proportions of CLA2 in the total FA of liver lipids were substantially lower than those …
Visceral obesity and metabolic syndrome: two faces of the same medal?
2009
In this review, we have analyzed the role of visceral obesity in the occurrence of metabolic syndrome (MetS). MetS is a common metabolic disorder that has been related recently to the increasing prevalence of obesity. The disorder is defined in various ways, but in the near future a new definition(s) should be applicable worldwide. The pathophysiology has been largely attributed, in the past years, to insulin resistance, although several epidemiological and pathophysiological data now indicate visceral obesity as a main factor in the occurrence of all the components of MetS. In view of this, relationships among visceral obesity, free fatty acids, dyslipidemia and insulin resistance have bee…
Investigation of absorber and heterojunction in the pure sulphide kesterite
2021
This paper aims to study the properties of the absorber layer and the heterojunction in kesterite solar cells. The Cu2ZnSnS4 (CZTS) thin films were layered on a glass substrate from a colloidal solution of metal salts and thiourea dissolved in a mixture of water and ethanol and deposited by spin coating technique. The samples were then heat treated in a furnace, in the presence of sulphur powder and under a nitrogen gas flow. The results revealed the formation of homogeneous layers of a pure kesterite phase of CZTS crystallites after heat treatment with correct stoichiometry and oxidation states. The optical transmission measurements indicate an energy band-gap of 1.4 eV and an absorption c…
Influence of calcination on the structural properties of earth abundant Cu2ZnSnS4
2021
Abstract In the present work, we report on the synthesis of nano-crystalline kesterite copper zinc tin sulfide (CZTS) in powder form and the post-annealing process at high temperatures (calcination), and study their physical properties. We have successfully synthesized CZTS by direct fusion, and the resulting material was crushed to obtain a fine powder. Then, the resulting powder was calcined at high temperatures: 800–1000 ∘C. The calcined samples have been characterized with a number of different structural: X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and optical techniques: photoluminescence (PL), Raman and diffuse reflectance spectr…