Search results for "lipoprotein lipase"
showing 10 items of 41 documents
Rat Plasma VLDL Composition and Concentration and Hepatic Lipase and Lipoprotein Lipase Activities Are Impaired during Two Types of Protein Malnutrit…
1995
The relationships between VLDL concentrations and composition and changes in hepatic lipase and lipoprotein lipase activities were determined in rats, during the consumption of two low protein diets (2% casein or 5% gluten) (protein malnutrition) for 28 d, followed by the refeeding of a balanced diet for 14 d (15% casein) (refeeding). A control group was fed 15% casein for 42 d. In the control group, total lipolytic activity increased with age (r = 0.83, P < 0.001), whereas in both depleted groups, this activity remained low and stable throughout the period of protein malnutrition. At d 28 of protein malnutrition, plasma total lipolytic activities were significantly reduced in both depleted…
Liraglutide Reduces Postprandial Hyperlipidemia by Increasing ApoB48 (Apolipoprotein B48) Catabolism and by Reducing ApoB48 Production in Patients Wi…
2018
Objective— Treatment with liraglutide, a GLP-1 (glucagon-like peptide-1) agonist, has been shown to reduce postprandial lipidemia, an important feature of diabetic dyslipidemia. However, the underlying mechanisms for this effect remain unknown. This prompted us to study the effect of liraglutide on the metabolism of ApoB48 (apolipoprotein B48). Approach and Results— We performed an in vivo kinetic study with stable isotopes (D 8 -valine) in the fed state in 10 patients with type 2 diabetes mellitus before treatment and 6 months after the initiation of treatment with liraglutide (1.2 mg/d). We also evaluated, in mice, the effect of a 1-week liraglutide treatment on postload triglycerides an…
Apolipoprotein CI is a physiological regulator of cholesteryl ester transfer protein activity in human plasma but not in rabbit plasma
2009
Plasma cholesteryl ester transfer protein (CETP) activity is high in rabbits, intermediate in humans, and nondetectable in rodents. Human apolipoprotein CI (apoCI) was found to be a potent inhibitor of CETP. The aim of this study was to compare the ability of rabbit and human apoCI to modulate the interaction of CETP with HDLs and to evaluate to which extent apoCI contributes to plasma cholesteryl ester transfer rate in normolipidemic humans and rabbits. Rabbit apoCI gene was cloned and sequenced, rabbit and human apoCI were purified to homogeneity, and their ability to modify the surface charge properties and the CETP inhibitory potential of HDL were compared. It is demonstrated that unlik…
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…
Lymphatic Delivery and In Vitro Pancreatic Lipase Hydrolysis of Glycerol Esters of Conjugated Linoleic Acids in Rats
2000
We examined the intestinal delivery of conjugated linoleic acids (CLA) given in their triacylglycerol form in the mesenteric lymph of rats. Emulsions containing a mixture of the trilinolein/triester of CLA (9:1) and a tri-[1-(14)C]-linoleyl-sn-glycerol tracer were administered by force-feeding. Lymph was collected over two time periods (0-6 and 6-24 h), and the apparent recovery of CLA was determined relative to that of [1-(14)C]-18:2(n-6). A mixture of CLA-triester/trilinolein (1:9), trilinolein or CLA-triester was separately subjected to pancreatic lipase hydrolysis in vitro to determine whether the lymphatic recovery of CLA was correlated with the initial step of digestion. Lymphatic rec…
Spectrum of mutations of the LPL gene identified in Italy in patients with severe hypertriglyceridemia.
2015
Background: Monogenic hypertriglyceridemia (HTG) may result from mutations in some genes which impair the intravascular lipolysis of triglyceride (TG)-rich lipoproteins mediated by the enzyme Lipoprotein lipase (LPL). Mutations in the LPL gene are the most frequent cause of monogenic HTG (familial chylomicronemia) with recessive transmission. Methods: The LPL gene was resequenced in 149 patients with severe HTG (TG>10mmol/L) and 106 patients with moderate HTG (TG>4.5 and <10mmol/L) referred to tertiary Lipid Clinics in Italy. Results: In the group of severe HTG, 26 patients (17.4%) were homozygotes, 9 patients (6%) were compound heterozygotes and 15 patients (10%) were simple heter…
Low-protein diet prevents tissue lipoprotein lipase activity increase in growing rats
2000
The time course of changes in tissue lipolytic activities was studied in young rats during theconsumption of a low-protein diet containing 50 g protein/kg (40 g wheat gluten +10 g casein/kg) for 28 d followed by balanced refeeding with 200 g protein/kg (160 g wheat gluten +40 gcasein/kg) for 28 d. Lipoprotein lipase (LPL) activities were compared with the values of acontrol group fed a balanced diet containing 200 g protein/kg for 56 d. At the end of proteinmalnutrition period, the epididymal fat tissue LPL activity represented 36 %, and that of heartand gastrocnemius was 44 %, of those of the control group. These differences wereaccompanied by lower serum- and VLDL-triacylglycerols (TAG), …
Paracrine Activation of Hepatic CB1 Receptors by Stellate Cell-Derived Endocannabinoids Mediates Alcoholic Fatty Liver
2008
SummaryAlcohol-induced fatty liver, a major cause of morbidity, has been attributed to enhanced hepatic lipogenesis and decreased fat clearance of unknown mechanism. Here we report that the steatosis induced in mice by a low-fat, liquid ethanol diet is attenuated by concurrent blockade of cannabinoid CB1 receptors. Global or hepatocyte-specific CB1 knockout mice are resistant to ethanol-induced steatosis and increases in lipogenic gene expression and have increased carnitine palmitoyltransferase 1 activity, which, unlike in controls, is not reduced by ethanol treatment. Ethanol feeding increases the hepatic expression of CB1 receptors and upregulates the endocannabinoid 2-arachidonoylglycer…
Alterations in the Hippocampal Endocannabinoid System in Diet-Induced Obese Mice
2010
The endocannabinoid (eCB) system plays central roles in the regulation of food intake and energy expenditure. Its alteration in activity contributes to the development and maintenance of obesity. Stimulation of the cannabinoid receptor type 1 (CB1receptor) increases feeding, enhances reward aspects of eating, and promotes lipogenesis, whereas its blockade decreases appetite, sustains weight loss, increases insulin sensitivity, and alleviates dysregulation of lipid metabolism. The hypothesis has been put forward that the eCB system is overactive in obesity. Hippocampal circuits are not directly involved in the neuronal control of food intake and appetite, but they play important roles in hed…
Regulation of lipid flux between liver and adipose tissue during transient hepatic steatosis in carnitine-depleted rats
2007
Rats with carnitine deficiency due to trimethylhydrazinium propionate (mildronate) administered at 80 mg/100 g body weight per day for 10 days developed liver steatosis only upon fasting. This study aimed to determine whether the transient steatosis resulted from triglyceride accumulation due to the amount of fatty acids preserved through impaired fatty acid oxidation and/or from up-regulation of lipid exchange between liver and adipose tissue. In liver, mildronate decreased the carnitine content by approximately 13-fold and, in fasted rats, lowered the palmitate oxidation rate by 50% in the perfused organ, increased 9-fold the triglyceride content, and doubled the hepatic very low density …