Search results for "LIPID"

Hardwiring the Brain: Endocannabinoids Shape Neuronal Connectivity

2007

The roles of endocannabinoid signaling during central nervous system development are unknown. We report that CB 1 cannabinoid receptors (CB 1 Rs) are enriched in the axonal growth cones of γ-aminobutyric acid–containing (GABAergic) interneurons in the rodent cortex during late gestation. Endocannabinoids trigger CB 1 R internalization and elimination from filopodia and induce chemorepulsion and collapse of axonal growth cones of these GABAergic interneurons by activating RhoA. Similarly, endocannabinoids diminish the galvanotropism of Xenopus laevis spinal neurons. These findings, together with the impaired target selection of cortical GABAergic interneurons lacking CB 1 Rs, identify endoc…

Exercise, the endocannabinoid system and metabolic health

2013

As obesity and associated metabolic disorders, such as type 2 diabetes and dyslipidemia, are becoming one of the most serious health problems worldwide, development of effective therapies is a high priority. In the search for treatments, the recently discovered endocannabinoid system (ECS) has begun to garner attention, and a wealth of research is now focusing on this unique neuromodulatory system named after the plant that led to its discovery. The ECS consists of G protein-coupled cannabinoid receptors (CB1 and CB2), their endogenous lipid-derived ligands (endocannabinoids, N-arachidonoylethanolamine, named anandamide (AEA) and 2-arachidonoylglycerol (2-AG)) and the enzymes for ligand syn…

Mucosa-dependent muscarinic liberation of prostaglandins from rat isolated trachea.

1995

1. The present study examined whether cholinoceptor stimulation modulates the release of arachidonic acid-derived mediators from rat isolate tracheae. 2. Tracheae were preincubated with [3H]-arachidonic acid and the outflow of 3H-compounds was determined. Acetylcholine and the muscarinic agonist, carbachol but not nicotine, increased the rate of tritium outflow maximally by about 30%. The M3 receptor-preferring antagonist rho-fluoro-hexahydrosiladiphenidol was more effective than pirenzepine and methoctramine in antagonizing the effect of acetylcholine. 3. High performance liquid chromatography analysis (methanol gradient) of the released 3H-compounds showed that one peak, co-eluting with […

The release of choline from phospholipids mediated by beta-adrenoceptor activation in isolated hearts.

1986

The resting efflux of choline into the perfusate (Tyrode's solution) of isolated hearts was equal to the rate, at which choline was liberated from phospholipid degradation (Lindmar et al. 1986). Infusion of isoprenaline (2 X 10(-7) mol/l), forskolin (1-3 X 10(-6) mol/l) or 3-isobutyl-1-methylxanthine (IBMX; 3 X 10(-4) mol/l) for 40 min markedly enhanced the efflux of choline. The increase was linear during the experimental period and, in the case of isoprenaline, was blocked by 3 X 10(-7) mol/l atenolol. In the guinea-pig heart, IBMX at a threshold concentration of 10(-4) mol/l shifted the concentration-response curve for the effect of forskolin on the efflux of choline to the left by one l…

A Review of the Cardiovascular and Anti-Atherogenic Effects of Ghrelin

2013

Ghrelin is a peptide hormone produced mainly in the stomach that has widespread tissue distribution and diverse hormonal, metabolic and cardiovascular activities. The circulating ghrelin concentration increases during fasting and decreases after food intake. Ghrelin secretion may thus be initiated by food intake and is possibly controlled by nutritional factors. Lean subjects have increased levels of circulating ghrelin compared with obese subjects. Recent reports show that low plasma ghrelin is associated with elevated fasting insulin levels, insulin resistance and type 2 diabetes mellitus. Factors involved in the regulation of ghrelin secretion have not yet been defined; however, it is as…

Effects of Norepinephrine and Cardiotrophin-1 on Phospholipase D Activity and Incorporation of Myristic Acid Into Phosphatidylcholine in Rat Heart

2004

The present study is part of a project on phospholipase D (PLD) in cardiac hypertrophy and analyzed effects on PLD activity of two growth stimuli, norepinephrine (NE) and cardiotrophin-1 (CT-1), in incubated rat heart. Phosphatidylcholine (PC) was labeled by 3H-myristic acid. PLD produced 3H-phosphatidylethanol (3H-PEth) from 3H-PC in the presence of ethanol and maintained a basal formation of 3H-PEth. Short-term and long-term exposure to NE for 2 or 13 h, respectively, enhanced the formation of 3H-PEth, which was blocked by prazosin. Long-term pretreatment with NE or CT-1 increased the incorporation of 3H-myristic acid into PC, which was blocked by atenolol. When the 3H-PEth formation was …

Do we need better lipid tools for cardiovascular risk assessment ?

2008

Hypolipidaemic effects of fenofibrate and fasting in the herbivorous grass carp (Ctenopharyngodon idella) fed a high-fat diet

2008

We investigated whether the hypolipidaemic effect of fenofibrate and fasting observed in most omnivorous mammals may also apply to herbivorous fish. Grass carp (Ctenopharyngodon idella) fed a high-fat (8 %) diet exhibited a marked increase in blood lipids and body fat after 6 weeks. They were then treated with fenofibrate (100 mg/kg body weight) in the same high-fat diet for 2 weeks, followed by fasting for 1 week. Plasma lipid concentration, body fat amount, fatty acid composition, plasma thiobarbituric acid-reactive substances and some parameters related to hepatic fatty acid oxidation were measured, and liver samples were stained for histological examination. Fenofibrate treatment decrea…

Cationic lipide mediated transfer of c-abl and bcr antisense oligonucleotides to immature normal myeloid cells: Uptake, biological effects and modula…

1996

Uptake and biochemical and biological effects of antisense oligodeoxynucleotides (ODN) specific for c-abl and bcr genes were studied in normal immature myeloid cells. CD34-positive cells were purified by positive and negative selection and cultured in liquid culture for 7 days. These cells were then incubated with ODNs, either alone or in combination with cationic lipids. The uptake of ODNs was enhanced by the use of cationic lipids. In addition, very low concentrations of ODNs in combination with cationic lipids were capable of specifically inhibiting the expression of the c-abl gene. In contrast, no effects were seen on the expression of bcr. However, despite the effective blocking of c-a…

Adaptation of neuronal cells to chronic oxidative stress is associated with altered cholesterol and sphingolipid homeostasis and lysosomal function

2009

Chronic oxidative stress has been causally linked to several neurodegenerative disorders. As sensitivity for oxidative stress greatly differs between brain regions and neuronal cell types, specific cellular mechanisms of adaptation to chronic oxidative stress should exist. Our objective was to identify molecular mechanisms of adaptation of neuronal cells after applying chronic sublethal oxidative stress. We demonstrate that cells resistant to oxidative stress exhibit altered cholesterol and sphingomyelin metabolisms. Stress-resistant cells showed reduced levels of molecules involved in cholesterol trafficking and intracellular accumulation of cholesterol, cholesterol precursors, and metabol…