scholarly journals The role of chloroplasts and microsomal fractions in polar-lipid synthesis from [1-14C]acetate by cell-free preparations from spinach (Spinacia oleracea) leaves

1980 ◽  
Vol 188 (1) ◽  
pp. 17-24 ◽  
Author(s):  
P G Roughan ◽  
R Holland ◽  
C R Slack
Keyword(s):  
Fatty Acids ◽  
Microsomal Fraction ◽  
Spinacia Oleracea ◽  
Lipid Synthesis ◽  
Free Medium ◽  
Plant Lipid ◽  
Esterified Fatty Acids ◽  
Isolated Chloroplasts

1. Isolated spinach (Spinacia oleracea) chloroplasts were incapable of accumulating polar lipids when incubated with [1-14C]acetate in a cofactor-free medium. When CoA, ATP and glycerol 3-phosphate were added to incubation media, the accumulated products were non-esterified fatty acids, acyl-CoA and 1,2-diacylglycerol, all intermediates of lipid metabolism. 2. Chloroplast acyl-CoA was used to synthesize phosphatidylcholine only when a microsomal fraction was added back to the incubation medium. 3. The 1,2-diacylglycerol synthesized by isolated chloroplasts was converted almost quantitatively into diacylgalactosylglycerol when exogenous UDP-galactose was available. 4. Stereospecific analyses of the isolated lipids suggested that the diacylglycerol synthesized by isolated chloroplasts may be an important precursor for the synthesis in vivo of diacylgalactosylglycerol and phosphatidylglycerol but was unlikely to be a precursor of phosphatidylcholine. 5. A scheme for plant-lipid biosynthesis is presented that integrates the functions of chloroplasts, the cytoplasm and the endoplasmic reticulum.

Plasmodium falciparum: Differing effects of non-esterified fatty acids and phospholipids on intraerythrocytic growth in serum-free medium

2011 ◽  
Vol 127 (3) ◽  
pp. 708-713 ◽  
Author(s):  
Hiroko Asahi ◽  
Shinji Izumiyama ◽  
Mohammed Essa Marghany Tolba ◽  
Bethel Kwansa-Bentum
Keyword(s):  
Fatty Acids ◽  
Plasmodium Falciparum ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Esterified Fatty Acids

IL-4 increases surfactant and regulates metabolism in vivo

2000 ◽  
Vol 278 (1) ◽  
pp. L75-L80 ◽  
Author(s):  
Machiko Ikegami ◽  
Jeffrey A. Whitsett ◽  
Zissis C. Chroneos ◽  
Gary F. Ross ◽  
Jacquelyn A. Reed ◽  
...  
Keyword(s):  
Lipid Synthesis ◽  
Fold Increase ◽  
Surfactant Protein ◽  
Clara Cells ◽  
Wild Type ◽  
Surfactant Lipid ◽  
Alveolar Proteinosis ◽  
Selective Increase

Mice that express interleukin (IL)-4 in Clara cells (CCSP-IL-4) develop chronic airway inflammation and an alveolar proteinosis-like syndrome. To identify the role of IL-4 in surfactant homeostasis, we measured lipid and protein metabolism in the lungs of CCSP-IL-4 mice in vivo. Alveolar saturated phosphatidylcholine (Sat PC) pools were increased 6.5-fold and lung tissue Sat PC pools were increased 4.8-fold in the IL-4 transgenic mice. Whereas surfactant protein (SP) A was increased proportionately to Sat PC, SP-D was increased approximately 90-fold in the IL-4 mice compared with wild-type mice and was associated with 2.8-fold increase in SP-D mRNA. The incorporation of palmitate and choline into Sat PC was increased about twofold in CCSP-IL-4 mice. Although trace doses of radiolabeled Sat PC were cleared from the air spaces and lungs of CCSP-IL-4 mice more slowly than in wild-type mice, net clearance of Sat PC from the lungs of CCSP-IL-4 mice was sixfold higher in the IL-4 mice than in wild-type mice because of the larger Sat PC pool sizes. Expression of IL-4 in Clara cells increased surfactant lipid synthesis and clearance, establishing a new equilibrium with increased surfactant pools and an alveolar proteinosis associated with a selective increase in SP-D protein, demonstrating a previously unexpected effect of IL-4 in pulmonary surfactant homeostasis.

Accumulation of Glycinebetaine in Chloroplasts Provides Osmotic Adjustment During Salt Stress

1986 ◽  
Vol 13 (5) ◽  
pp. 659 ◽  
Author(s):  
SP Robinson ◽  
GP Jones
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Salt Stress ◽  
Osmotic Adjustment ◽  
Osmotic Potential ◽  
Spinacia Oleracea ◽  
Resonance Spectroscopy ◽  
Leaf Osmotic Potential ◽  
Cellular Compartments ◽  
Isolated Chloroplasts

Glycinebetaine was determined in leaves and in isolated chloroplasts of spinach (Spinacia oleracea) by nuclear magnetic resonance spectroscopy. Some leakage of glycinebetaine from the chloroplasts occurred during the isolation so the concentration in chloroplasts in vivo could be up to 1.5 times higher than that measured in isolated chloroplasts. It was demonstrated that any contamination of the chloroplast preparations by glycinebetaine originating from other cellular compartments or from broken chloroplasts would have amounted to less than 10% of the measured values. Leaf osmotic potential of salt-stressed plants was -2.09 MPa compared to -0.91 MPa in non-stressed controls. This was accompanied by a sixfold increase in glycinebetaine content in the leaf but the levels of choline and proline were not increased. In chloroplasts isolated from control leaves the calculated glycinebetaine concentration was 26 mM which was 10-fold higher than the concentration in the leaf as a whole but only contributed 7% of the osmotic potential of the chloroplast. Chloroplasts from salt-stressed plants contained up to 300 mM glycinebetaine which was 20 times the concentration in the leaf as a whole. The glycinebetaine concentration in chloroplasts from salt-stressed leaves was equivalent to an osmotic potential of -0.75 MPa and this contributed 36% of the osmotic potential of the chloroplast and 64% of the decrease in osmotic potential induced by salt stress. At least 30-40% of the total leaf glycinebetaine was localized in the chloroplast. The results demonstrate that glycinebetaine accumulates in chloroplasts to provide osmotic adjustment during salt stress and provide support for the hypothesis that glycinebetaine is a compatible cytoplasmic solute which may be preferentially located in the cytoplasm of cells.

Thiocarbamate Inhibition of Fatty Acid Biosynthesis in Isolated Spinach Chloroplasts

Weed Science ◽  
1975 ◽  
Vol 23 (2) ◽  
pp. 100-104 ◽  
Author(s):  
R. E. Wilkinson ◽  
A. E. Smith
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Biosynthesis ◽  
Spinacia Oleracea ◽  
Lipid Synthesis ◽  
Metabolic Effects ◽  
Acid Biosynthesis ◽  
Spinach Chloroplasts ◽  
Physiological Range

EPTC (S-ethyl dipropylthiocarbamate) (33μM) and diallate [S-(2,3-dichloroallyl)diisopropylthiocarbamate] (90μM) inhibited the incorporation of 6 mM acetate-2-14C (Ac∗) by 80% and 65%, respectively, and the incorporation of 0.5μM malonate-2-14C (Mal∗) by 32% and 26%, respectively, into the lipids of spinach (Spinacia oleraceaL.) chloroplasts. The inhibition of Ac∗or Mal∗incorporation into lipids was not observed in the presence of excess Ac∗or Mal∗, respectively. Incorporation of palmitate-1-14C and oleate-1-14C into chloroplast lipids was inhibited by EPTC and diallate. Mal∗incorporation into dienoic fatty acids was inhibited by EPTC and diallate. The concentration of EPTC and diallate inhibiting lipid synthesis falls into the physiological range of these herbicides, explains some metabolic effects of these compounds, and fits as the mode of activity of these herbicides.

Central sympathetic outflow to skeletal muscle: the major link between non-esterified fatty acids and elevated blood pressure?

2009 ◽  
Vol 118 (1) ◽  
pp. 43-45 ◽  
Author(s):  
Markus Schlaich
Keyword(s):  
Blood Pressure ◽  
Fatty Acids ◽  
Pressor Response ◽  
The Metabolic Syndrome ◽  
Arterial Blood ◽  
Esterified Fatty Acids ◽  
System Activation ◽  
Central Sympathetic Outflow ◽  
Sympathetic Nervous System Activation

Sympathetic nervous system activation is a hallmark of several conditions associated with an adverse prognosis, including hypertension and the metabolic syndrome. Proposed mediators of increased sympathetic drive include hyperinsulinaemia, leptin, NEFAs (non-esterified fatty acids), pro-inflammatory cytokines, baroreflex impairment and others. The role of NEFAs appears to be of particular importance given the increased levels observed in human obesity and the experimental results linking the NEFA-induced pressor response to sympathetic activation. Findings from human studies have yielded conflicting results with regards to a sympathetically mediated association between NEFAs and elevated arterial blood pressure. In the present issue of Clinical Science, Florian and Pawelczyk present some interesting results obtained from a small number of healthy normotensive lean volunteers who were exposed to NEFA infusion and cardiovascular and sympathetic monitoring using state of the art methodology that appears to be in support of such a link. However, several methodological and conceptual considerations need to be taken into account when interpreting the results from this study. Put into perspective, the case for a substantial sympathetically mediated pressor response to NEFA infusion does not appear to be a very strong one.

Role of Nonesterified Fatty Acids in Necrotizing Pancreatitis: An In Vivo Experimental Study in Rats

Pancreas ◽  
2001 ◽  
Vol 23 (4) ◽  
pp. 341-348 ◽  
Author(s):  
François Paye ◽  
Olivier Presset ◽  
Jacques Chariot ◽  
Georges Molas ◽  
Claude Rozé
Keyword(s):  
Fatty Acids ◽  
Experimental Study ◽  
Necrotizing Pancreatitis ◽  
Nonesterified Fatty Acids

Influence of Simazine and Atrazine on Free Fatty Acid Content in Isolated Chloroplasts

Weed Science ◽  
1973 ◽  
Vol 21 (1) ◽  
pp. 57-60 ◽  
Author(s):  
A. E. Smith ◽  
R. E. Wilkinson
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Free Fatty Acid Content ◽  
Acid Content ◽  
Spinacia Oleracea ◽  
Saturated Fatty Acids ◽  
Fatty Acid Content ◽  
Total Fatty Acids ◽  
Isolated Chloroplasts

Chloroplasts, isolated from fresh spinach (Spinacia oleracea L.) were treated with four concentrations of each 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine) or 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) to determine the influence of these herbicides on the free fatty acid content in isolated chloroplasts. The treated chloroplast solutions were sampled at 0, 5, 15, 30, 60, and 120 min following treatment. Results indicated that most herbicide treatments increased free fatty acid content in isolated chloroplasts when compared with the zero concentration treatments. The increased fatty acid content was similar for most concentrations of simazine and atrazine. Results of individual fatty acid analyses indicated that the increase in total fatty acids was a result of increases in concentration of unsaturated rather than saturated fatty acids.

The effects of non-esterified fatty acids and β-hydroxybutyrate on the hepatic CYP2E1 in cows with clinical ketosis

2019 ◽  
Vol 86 (1) ◽  
pp. 68-72
Author(s):  
Zhicheng Peng ◽  
Xiaobing Li ◽  
Zhe Wang ◽  
Guowen Liu ◽  
Xinwei Li
Keyword(s):  
Oxidative Stress ◽  
Fatty Acids ◽  
Dairy Cows ◽  
Blood Concentrations ◽  
Cytochrome P4502e1 ◽  
Esterified Fatty Acids ◽  
Cyp2e1 Expression ◽  
Expression And Activity

AbstractDairy cows with ketosis display severe oxidative stress as well as high blood concentrations of non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB). Cytochrome P4502E1 (CYP2E1) plays an important role in the induction of oxidative stress. The aim of this study was to investigate CYP2E1 expression and activity in the liver of clinically ketotic cows (in vivo) and the effects of NEFA and BHB on CYP2E1 expression and activity in hepatocytes (in vitro). Dairy cows with clinical ketosis exhibited a low blood concentration of glucose but high concentrations of NEFA and BHB. Hepatic mRNA, protein expression, and activity of CYP2E1 were significantly higher in cows with clinical ketosis than in control cows. In vitro, both NEFA and BHB treatment markedly up-regulated the mRNA and protein expressions as well as activity of CYP2E1 in cow hepatocytes. Taken together, these results indicate that high levels of NEFA and BHB significantly up-regulate the expression and activity of hepatic CYP2E1, and may be influential in the induction of oxidative stress in cows with clinical ketosis.

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