In vivo esterification of a synthetic 125I-labeled fatty acid into cardiac glycerolipids

1983 ◽  
Vol 245 (4) ◽  
pp. H693-H697
Author(s):  
K. R. Chien ◽  
A. Han ◽  
J. White ◽  
P. Kulkarni
Keyword(s):  
Fatty Acid ◽  
Membrane Lipids ◽  
Lipid Fraction ◽  
Synthetic Fatty Acid ◽  
Water Soluble ◽  
Myocardial Imaging ◽  
Sprague Dawley ◽  
Membrane Phospholipids ◽  
Triglyceride Fraction

Recent studies have demonstrated that fatty acids can be successfully utilized as myocardial imaging agents. 125I-paraphenylpentadecanoic acid (IPPA), a synthetic fatty acid, accumulates within the myocardium and can be visualized by conventional gamma scintigraphy. To determine if IPPA was incorporated into cardiac lipids in a pattern similar to palmitate, IPPA was purified by liquid chromatography, bound to fat-free albumin, and administered by intravenous injection to male Sprague-Dawley rats. After 2.5, 5, 10, and 30 min, the hearts were excised and the lipids were extracted in chloroform-methanol. The uptake of IPPA into the myocardium reached a maximal value after 2.5 min, and 95% of the 125I was found in the cardiac lipid fraction after chromatographic separation. Over 65% of the IPPA was found in cardiac triglycerides, whereas approximately 10% was present in membrane phospholipids (predominantly phosphatidylcholine and phosphatidylethanolamine). This pattern of IPPA incorporation is similar to that reported for intravenously administered [3H]palmitate. The rate of turnover of IPPA present in the triglyceride fraction was threefold faster than the rate of the IPPA which was incorporated into membrane lipids. At all time periods examined, the methanol-water soluble end products of IPPA oxidation did not account for more than 5% of the total IPPA present within the myocardium. The present study indicates that IPPA is incorporated primarily into triglycerides and other cardiac lipids in a pattern similar to palmitate.

scholarly journals Membrane Translocation of 15-Lipoxygenase in Hematopoietic Cells Is Calcium-Dependent and Activates the Oxygenase Activity of the Enzyme

Blood ◽  
1998 ◽  
Vol 91 (1) ◽  
pp. 64-74 ◽  
Author(s):  
Roland Brinckmann ◽  
Kerstin Schnurr ◽  
Dagmar Heydeck ◽  
Thomas Rosenbach ◽  
Gerhard Kolde ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Immunoelectron Microscopy ◽  
Membrane Lipids ◽  
Membrane Binding ◽  
Hematopoietic Cells ◽  
Cell Fractionation ◽  
Calcium Dependent ◽  
Oxygenase Activity ◽  
Lipoxygenase Products

Abstract Mammalian 15-lipoxygenases, which have been implicated in the differentiation of hematopoietic cells are commonly regarded as cytosolic enzymes. Studying the interaction of the purified rabbit reticulocyte 15-lipoxygenase with various types of biomembranes, we found that the enzyme binds to biomembranes when calcium is present in the incubation mixture. Under these conditions, an oxidation of the membrane lipids was observed. The membrane binding was reversible and led to an increase in the fatty acid oxygenase activity of the enzyme. To find out whether such a membrane binding also occurs in vivo, we investigated the intracellular localization of the enzyme in stimulated and resting hematopoietic cells by immunoelectron microscopy, cell fractionation studies and activity assays. In rabbit reticulocytes, the 15-lipoxygenase was localized in the cytosol, but also bound to intracellular membranes. This membrane binding was also reversible and the detection of specific lipoxygenase products in the membrane lipids indicated the in vivo activity of the enzyme on endogenous substrates. Immunoelectron microscopy showed that in interleukin-4 –treated monocytes, the 15-lipoxygenase was localized in the cytosol, but also at the inner side of the plasma membrane and at the cytosolic side of intracellular vesicles. Here again, cell fractionation studies confirmed the in vivo membrane binding of the enzyme. In human eosinophils, which constitutively express the 15-lipoxygenase, the membrane bound share of the enzyme was augmented when the cells were stimulated with calcium ionophore. Only under these conditions, specific lipoxygenase products were detected in the membrane lipids. These data suggest that in hematopoietic cells the cytosolic 15-lipoxygenase translocates reversibly to the cellular membranes. This translocation, which increases the fatty acid oxygenase activity of the enzyme, is calcium-dependent, but may not require a special docking protein.

scholarly journals Haemophilus influenzae Rd Lacks a Stringently Conserved Fatty Acid Biosynthetic Enzyme and Thermal Control of Membrane Lipid Composition

2003 ◽  
Vol 185 (16) ◽  
pp. 4930-4937 ◽  
Author(s):  
Haihong Wang ◽  
John E. Cronan
Keyword(s):  
Fatty Acid ◽  
Haemophilus Influenzae ◽  
Growth Temperature ◽  
Acyl Carrier Protein ◽  
Thermal Control ◽  
Membrane Lipid ◽  
Membrane Phospholipids ◽  
E Coli ◽  
K 12

ABSTRACT The organization of the fatty acid synthetic genes of Haemophilus influenzae Rd is remarkably similar to that of the paradigm organism, Escherichia coli K-12, except that no homologue of the E. coli fabF gene is present. This finding is unexpected, since fabF is very widely distributed among bacteria and is thought to be the generic 3-ketoacyl-acyl carrier protein (ACP) synthase active on long-chain-length substrates. However, H. influenzae Rd contains a homologue of the E. coli fabB gene, which encodes a 3-ketoacyl-ACP synthase required for unsaturated fatty acid synthesis, and it seemed possible that the H. influenzae FabB homologue might have acquired the functions of FabF. E. coli mutants lacking fabF function are unable to regulate the compositions of membrane phospholipids in response to growth temperature. We report in vivo evidence that the enzyme encoded by the H. influenzae fabB gene has properties essentially identical to those of E. coli FabB and lacks FabF activity. Therefore, H. influenzae grows without FabF function. Moreover, as predicted from studies of the E. coli fabF mutants, H. influenzae is unable to change the fatty acid compositions of its membrane phospholipids with growth temperature. We also demonstrate that the fabB gene of Vibrio cholerae El Tor N16961 does not contain a frameshift mutation as was previously reported.

scholarly journals Therapeutic Effects of Water Soluble Danshen Extracts on Atherosclerosis

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Yoon Hee Cho ◽  
Cheol Ryong Ku ◽  
Zhen-Yu Hong ◽  
Ji Hoe Heo ◽  
Eun Hee Kim ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Platelet Aggregation ◽  
Ex Vivo ◽  
Umbilical Vein ◽  
Water Soluble ◽  
Therapeutic Effects ◽  
Sprague Dawley ◽  
Tail Vein ◽  
Vein Thrombosis

Danshen is a traditional Chinese medicine with many beneficial effects on cardiovascular diseases. The aim of this study was to evaluate the mechanisms responsible for the antiatherogenic effect of water soluble Danshen extracts (DEs). Rat vascular smooth muscle cells (VSMCs) and human umbilical vein endothelial cells (HUVECs) were treated with DE. To evaluate the effects of DEin vivo, carotid balloon injury and tail vein thrombosis were induced in Sprague-Dawley (SD) rats and iliac artery stent was induced in New Zealand white rabbits. The inhibitory action of DE on platelet aggregation was confirmed with an impedance aggregometer. DE inhibited the production of reactive oxygen species, and the migration and proliferation of platelet-derived growth factor-BB stimulated VSMCs. Furthermore, DE prevented inflammation and apoptosis in HUVECs. Both effects of DE were reconfirmed in both rat models. DE treatment attenuated platelet aggregation in bothin vivoandex vivoconditions. Pretreatment with DE prevented tail vein thrombosis, which is normally induced byκ-carrageenan injection. Lastly, DE-treated rabbits showed decreased in-stent restenosis of stented iliac arteries. These results suggest that water soluble DE modulates key atherogenic events in VSMCs, endothelial cells, and platelets in bothin vitroandin vivoconditions.

scholarly journals FadD Is Required for Utilization of Endogenous Fatty Acids Released from Membrane Lipids

2011 ◽  
Vol 193 (22) ◽  
pp. 6295-6304 ◽  
Author(s):  
Ángel Pech-Canul ◽  
Joaquina Nogales ◽  
Alfonso Miranda-Molina ◽  
Laura Álvarez ◽  
Otto Geiger ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Stationary Phase ◽  
Free Fatty Acids ◽  
Sinorhizobium Meliloti ◽  
Membrane Lipids ◽  
Membrane Phospholipids ◽  
Content Type ◽  
Fatty Acid Transporter ◽  
In The Wild

FadD is an acyl coenzyme A (CoA) synthetase responsible for the activation of exogenous long-chain fatty acids (LCFA) into acyl-CoAs. Mutation offadDin the symbiotic nitrogen-fixing bacteriumSinorhizobium melilotipromotes swarming motility and leads to defects in nodulation of alfalfa plants. In this study, we found thatS. melilotifadDmutants accumulated a mixture of free fatty acids during the stationary phase of growth. The composition of the free fatty acid pool and the results obtained after specific labeling of esterified fatty acids with a Δ5-desaturase (Δ5-Des) were in agreement with membrane phospholipids being the origin of the released fatty acids.Escherichia colifadDmutants also accumulated free fatty acids released from membrane lipids in the stationary phase. This phenomenon did not occur in a mutant ofE. coliwith a deficient FadL fatty acid transporter, suggesting that the accumulation of fatty acids infadDmutants occurs inside the cell. Our results indicate that, besides the activation of exogenous LCFA, in bacteria FadD plays a major role in the activation of endogenous fatty acids released from membrane lipids. Furthermore, expression analysis performed withS. melilotirevealed that a functional FadD is required for the upregulation of genes involved in fatty acid degradation and suggested that in the wild-type strain, the fatty acids released from membrane lipids are degraded by β-oxidation in the stationary phase of growth.

2-Mercaptoacetate, an inhibitor of fatty acid oxidation, decreases the membrane potential in rat liver in vivo

1999 ◽  
Vol 277 (1) ◽  
pp. R301-R305 ◽  
Author(s):  
Sandra Boutellier ◽  
Thomas A. Lutz ◽  
Matthias Volkert ◽  
Erwin Scharrer
Keyword(s):  
Fatty Acid ◽  
Membrane Potential ◽  
Food Intake ◽  
Fatty Acid Oxidation ◽  
Intraperitoneal Injection ◽  
Acid Oxidation ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Intraportal Infusion

In former work, intraperitoneal injection of 2-mercaptoacetate (MA), an inhibitor of fatty acid oxidation, increased food intake in rats, which was attenuated by hepatic branch vagotomy, and intraportal injection of MA increased the discharge rate in hepatic vagal afferents. In the present study, we investigated, whether intraperitoneal injection or intraportal infusion of MA affects the hepatic membrane potential in rats in vivo. The liver cell membrane potential was measured in anesthetized Sprague-Dawley rats with the microelectrode technique. Intraperitoneal injection of MA at a dose of 800 μmol/kg body wt significantly decreased the hepatocyte membrane potential by 3.8 mV, whereas at a dose of 400 μmol/kg, the depolarization (1.5 mV) of the membrane was not significant. In another strain of Sprague-Dawley rats, however, MA (400 μmol/kg) produced a significant depolarization of the hepatocyte membrane 50 min (2.6 mV) and 2 h (2.9 mV) after intraperitoneal injection. Intraportal infusion of MA (400 μmol/kg) significantly depolarized the membrane 20 and 50 min after infusion by 3.3 and 4.1 mV, respectively. MA at a dose of 800 μmol/kg also depolarized the membrane (4.8 mV after 50 min). These findings in principle are consistent with the “potentiostatic” hypothesis, postulating a link between the hepatic membrane potential, afferent vagal activity, and the control of food intake.

scholarly journals Pharmacokinetics of Amino Acid Phosphoramidate Monoesters of Zidovudine in Rats

2002 ◽  
Vol 46 (5) ◽  
pp. 1357-1363 ◽  
Author(s):  
Heng Song ◽  
George W. Griesgraber ◽  
Carston R. Wagner ◽  
Cheryl L. Zimmerman
Keyword(s):  
Amino Acid ◽  
High Performance ◽  
Volume Of Distribution ◽  
Water Soluble ◽  
Pharmacokinetic Parameters ◽  
Sprague Dawley ◽  
Binding Studies ◽  
Total Body

ABSTRACT In vitro studies have demonstrated that water-soluble, nontoxic phosphoramidates of azidothymidine (zidovudine [AZT]) have significant and specific anti-human immunodeficiency virus and anticancer activity. Although polar, these compounds are internalized and processed to the corresponding nucleoside monophosphates. Eight methyl amide and methyl ester phosphoramidate monoesters composed of d- or l-phenylalanine or tryptophan and AZT were synthesized. The plasma stability and protein binding studies were carried out in vitro. Then in vivo pharmacokinetic evaluations of six of the compounds were conducted. Sprague-Dawley rats received each compound by intravenous bolus dose, and serial blood and urine samples were collected. AZT and phosphoramidate concentrations in plasma and urine were quantitated by high-performance liquid chromatography with UV or fluorescence detection. Pharmacokinetic parameters were calculated by standard noncompartmental means. The plasma half-lives of the phosphoramidates were 10- to 20-fold longer than the half-life of AZT. Although the renal clearances of the phosphoramidates were similar to AZT, their total body clearances were significantly greater than that of AZT. The 3- to 15-fold-larger volume of distribution (V ss) for the phosphoramidates relative to AZT appeared to be dependent on the stereochemistry of the amino acid, with the largest values being associated with the l-amino acids. The increased V ss indicates a much greater tissue distribution of the phosphoramidate prodrugs than of AZT. Amino acid phosphoramidate monoesters of AZT have improved pharmacokinetic properties over AZT and significant potential as in vivo pronucleotides.

Selenium-Containing Curcumin Polymer for Anti-Liver Fibrosis

2011 ◽  
Vol 311-313 ◽  
pp. 1061-1064
Author(s):  
Yi Feng Zhu ◽  
Jing Neng ◽  
Lei Lei He ◽  
Hua Dong Tang
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Amino Acid ◽  
Liver Fibrosis ◽  
Water Soluble ◽  
Sprague Dawley ◽  
Sprague Dawley Rats

A new selenium-containing curcumin polymer was synthesized by polycondensation of curcumin with dihydride, polyethylene glycol, and selenium amino acid monomers. The polymer was stable, water soluble, and injectable with a molecular weight of 6.1x104Da. The in vivo anti-liver fibrosis efficacy of the polymer was investigated with Sprague Dawley rats. The results showed the curcumin polymer had strong anti-hepafibrosis activity.

Removal of Protein-Bound Uremic Toxins by Liposome-Supported Peritoneal Dialysis

2019 ◽  
Vol 39 (6) ◽  
pp. 509-518
Author(s):  
Yuanyuan Shi ◽  
Huajun Tian ◽  
Yifeng Wang ◽  
Yue Shen ◽  
Qiuyu Zhu ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Uremic Toxins ◽  
Water Soluble ◽  
Sprague Dawley ◽  
Promising Alternative ◽  
Small Water ◽  
Artificial Plasma ◽  
End Stage

Background Protein-bound uremic toxins (PBUTs) are poorly cleared by peritoneal dialysis (PD). This study aimed to enhance PBUT removal in PD by adding a binder to the peritoneal dialysate and to evaluate the feasibility and efficacy of liposome-supported PD (LSPD) to increase the removal of PBUTs compared with albumin PD. Methods Removal of p-cresyl sulfate (PCS), indoxyl sulfate (IS), and indole-3-acetic acid (3-IAA) was first evaluated in an in vitro PD model using artificial plasma preloaded with test solutes. Male Sprague-Dawley rats ( n = 24) were then subjected to 5/6 nephrectomy and fed for 16 weeks to establish end-stage renal failure, after which they were treated with either conventional glucose-based PD, albumin-based PD, or liposome-based PD. Removal of PBUTs and small water-soluble solutes was determined during a 6-hour PD dwell. Results In vitro experiments showed that adding albumin as a toxin binder to the dialysate markedly increased the removal of PCS, IS, and 3-IAA compared with the control. The uptake capacity of liposomes was comparable with that of albumin for PCS and 3-IAA, though slightly inferior for IS. In vivo PD in uremic rats demonstrated that LSPD resulted in higher intraperitoneal concentrations and more total mass removal for PBUTs than the conventional glucose-based PD, which was comparable with albumin PD. Conclusions Supplementing conventional glucose-based PD solutions with a binder could efficiently increase the removal of PBUTs. This preliminary study suggested that LSPD may be a promising alternative to albumin PD for increasing PBUT removal in the development of next-generation PD solutions for PD patients.

scholarly journals Glycerol and fatty acid kinetics in rainbow trout: effects of endurance swimming

1999 ◽  
Vol 202 (3) ◽  
pp. 279-288 ◽  
Author(s):  
S.F. Bernard ◽  
S.P. Reidy ◽  
G. Zwingelstein ◽  
J. Weber
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Rainbow Trout ◽  
Body Temperature ◽  
Submaximal Exercise ◽  
Membrane Phospholipids ◽  
Esterified Fatty Acids ◽  
Fatty Acid Release ◽  
Acid Release

Continuous infusions of 2-[3H]glycerol and 1-[14C]palmitate were performed in vivo in rainbow trout to measure the effects of prolonged swimming on (1) the rate of appearance of glycerol (Ra glycerol or lipolytic rate), (2) the rate of appearance of non-esterified fatty acids (Ra NEFA) and (3) the rate of triacylglycerol:fatty acid cycling (TAG:FA cycling or re-esterification). Our goals were to test the hypothesis that sustained exercise for up to 4 days causes the progressive mobilization of triacylglycerol reserves to supply fuel to contracting muscles, and to assess whether TAG:FA cycling plays a role in the regulation of NEFA availability in teleosts. Contrary to expectation, the rates of lipolysis and fatty acid release in resting trout are not affected by endurance exercise. Unlike mammals, which increase the rate of lipolysis by two- to fourfold during submaximal exercise, these active teleosts do not mobilize triacylglycerol reserves beyond resting levels to supply more NEFAs to working muscles. Furthermore, they maintain Ra glycerol and Ra NEFA well in excess of oxidative fuel requirements even at rest. More than two-thirds of the NEFAs produced are re-esterified, but the results show that TAG:FA cycling is not involved in the regulation of NEFA availability during or after swimming. We propose that the observed high rates of re-esterification represent an important feature of ectothermic metabolism that allows the restructuring of membrane phospholipids to be synchronized with frequent changes in body temperature.

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