Phase properties of membranes after freezing injury in winter wheat

1985 ◽  
Vol 63 (12) ◽  
pp. 2274-2277 ◽  
Author(s):  
Edward J. Kendall ◽  
Bryan D. McKersie ◽  
Robert H. Stinson
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Structural Change ◽  
Free Fatty Acids ◽  
Membrane Fraction ◽  
Freezing Stress ◽  
Freezing Injury ◽  
Membrane Properties ◽  
Lipid Phase ◽  
Total Lipid Extract

The structural and compositional changes which occur in cellular membranes after freezing stress were examined in a microsomal membrane fraction from the crown tissue of 7-day-old, nonacclimated Triticum aestivum L. cv. Fredrick seedlings, which were frozen to a lethal temperature of −12 °C. The freezing treatment induced a lipid phase separation and increased the gel to liquid – crystalline phase transition temperature of the isolated membrane fraction from 25 to 65 °C as detected by wide-angle X-ray diffraction. This structural change was not accompanied by significant changes in the fatty acid saturation of the total lipid extract or by changes in the free sterol components, but a 13-fold increase in the free fatty acid – phospholipid ratio was observed in the membranes from the freeze-stressed tissue. It is proposed that the accumulations of free fatty acids and other phospholipid degradation products in the membrane are factors relating to the formation of extensive gel-phase domains and that this structural change contributes to the changes in membrane properties, such as loss of semipermeability and osmotic responsiveness, which are typically observed after freezing stress. Possible mechanisms leading to the accumulation of free fatty acids are discussed.

Fatty Acid Profiles of Main Lipid Classes in Adult Chrysomela vigintipunctata (Scopoli) (Coleopterai:Chrysomelidae)

2000 ◽  
Vol 55 (7-8) ◽  
pp. 661-666 ◽  
Author(s):  
Nelly Nikolova ◽  
Tomas Rezanka ◽  
Boryana Nikolova-Damyanova
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Monounsaturated Fatty Acids ◽  
Carbon Chain ◽  
Leaf Beetle ◽  
Polar Lipids ◽  
Total Lipid Extract ◽  
Branched Chains ◽  
Willow Leaf Beetle

Abstract The fatty acid composition of the willow leaf beetle Chrysomela vigintipunctata (Scopoli) (Coleoptera: Chrysomelidae) is presented in this paper. Fatty acids in the total lipid extract, triacylglycerols, free fatty acids and polar lipids were compared. One hundred and fifteen fatty acids were identified in the total lipids. The mixture comprised compounds with normal and branched-chains of 12-30 carbon atoms and zero to six double bonds in different positions in the carbon chain. Substantial amounts of unsaturated eicosanoic fatty acids known as important precursor of eicosanoids in insects were detected in the lipids as were biologically significant positionally isomeric dienes, trienes and tetraenes of the series (n-3) and (n-6) of C16, C18, and C22 fatty acids. Also present was a mixture of hydroxy-FA. Triacylglycerols contained mostly saturated and monounsaturated fatty acids. Polyunsaturated fatty acids were found mostly in free fatty acids and especially in polar lipids.

scholarly journals Biogenesis of mitochondria*. The effects of altered membrane lipid composition on cation transport by mitochondria of Saccharomyces cerevisiae

1973 ◽  
Vol 134 (4) ◽  
pp. 949-957 ◽  
Author(s):  
J. M. Haslam ◽  
T. W. Spithill ◽  
Anthony W. Linnane ◽  
J. B. Chappell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Oxidative Phosphorylation ◽  
Free Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Cation Transport ◽  
Lipid Phase ◽  
Yeast Mitochondria ◽  
Passive Permeability

1. The fatty acid composition of the membrane lipids of a fatty acid desaturase mutant of Saccharomyces cerevisiae was manipulated by growing the organism in a medium containing defined fatty acid supplements. 2. Mitochondria were obtained whose fatty acids contain between 20% and 80% unsaturated fatty acids. 3. Mitochondria with high proportions of unsaturated fatty acids in their lipids have coupled oxidative phosphorylation with normal P/O ratios, accumulate K+ ions in the presence of valinomycin and an energy source, and eject protons in an energy-dependent fashion. 4. If the unsaturated fatty acid content of the mitochondrial fatty acids is lowered to 20%, the mitochondria simultaneously lose active cation transport and the ability to couple phosphorylation to respiration. 5. The loss of energy-linked reactions is accompanied by an increased passive permeability of the mitochondria to protons. 6. Free fatty acids uncouple oxidative phosphorylation in yeast mitochondria and the effect is reversed by bovine serum albumin. 7. The free fatty acid contents of yeast mitochondria are unaffected by depletion of unsaturated fatty acids, and free fatty acids are not responsible for the uncoupling of oxidative phosphorylation in organelles depleted in unsaturated fatty acids. 8. It is suggested that the loss of energy-linked reactions in yeast mitochondria that are depleted in unsaturated fatty acids is a consequence of the increased passive permeability to protons, and is caused by a change in the physical properties of the lipid phase of the inner mitochondrial membrane.

scholarly journals Seasonal changes in bovine fertility: relation to developmental competence of oocytes, membrane properties and fatty acid composition of follicles

Reproduction ◽  
2001 ◽  
pp. 447-454 ◽  
Author(s):  
Y Zeron ◽  
A Ocheretny ◽  
O Kedar ◽  
A Borochov ◽  
D Sklan ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Chemical Activation ◽  
Blastocyst Stage ◽  
Membrane Properties ◽  
Lipid Phase

Follicle dynamics and oocyte viability in Holstein primiparous and multiparous cows and the relationships between fertility and the biochemical and physical properties of oocyte membranes with season were examined. The conception rates of primiparous (n = 70 885) and multiparous (n = 143 490) cows differed, peaking in the winter and decreasing in the summer. The number of follicles 3-8 mm in diameter per ovary was higher in winter (19.6) compared with summer (12.0). However, in winter the percentage of ovaries with fewer than ten follicles per ovary was 16%, in contrast to 50% in summer. After aspiration of follicles, 7.5 oocytes per ovary were found in winter and 5.0 oocytes per ovary in summer. Cleavage to the two- to four-cell stage after chemical activation was greater in winter than in summer; this was enhanced at the morula stage and embryo development to the blastocyst stage was significantly higher in winter than in summer. Determination of the lipid phase transition in oocyte membranes revealed a shift of 6 degrees C between summer and winter. Fatty acid composition of phospholipids from follicular fluid, granulosa cells and oocytes indicated that there was a higher percentage of saturated fatty acids during the summer and that the percentages of mono-unsaturated and polyunsaturated fatty acids were higher in oocytes and granulosa cells during the winter. Oocytes and granulosa cells had similar fatty acid compositions, in contrast to follicular fluid. These results may explain the differences in the ability of oocytes to develop to the blastocyst stage at different seasons. Thus, temperature changes may lead to changes in membrane properties, which, in turn, can influence oocyte function and fertility.

The composition of lipids in intestinal digesta of young pigs receiving diets containing tallow and tallow fatty acids

1976 ◽  
Vol 54 (5) ◽  
pp. 728-735
Author(s):  
Lynn D. Swiss ◽  
F. D. Horney ◽  
H. S. Bayley
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Free Fatty Acids ◽  
Aqueous Phase ◽  
Beef Tallow ◽  
Intestinal Lumen ◽  
Lipid Phase ◽  
Acid Diet ◽  
Young Pigs

Three semipurified diets containing a low level of fat or 10% of either beef tallow or beef tallow free fatty acids were fed to young pigs. Jejunal digesta was sampled 1.5, 2.5, 3.5, and 4.5 h after feeding by aspiration through tubes leading from the jejunal lumen to the exterior. The samples were forced through Millipore filters (1 × 10−7 m pore size) to separate aqueous phase and oil phase lipid. The total and aqueous phase lipid was separated into triglyceride, monoglyceride, and free fatty acid, and the fatty acid composition of each fraction determined. The concentration of aqueous phase lipid was not influenced by diet, although the concentration of the oil phase lipid was generally higher for the addition of fat to the diets; the increase was greater for the beef tallow free fatty acid diet than for the beef tallow diet. Free fatty acids were the predominant component of the aqueous phase lipid along with some monoglyceride and traces of triglyceride. The major component of the oil phase lipid was free fatty acid but there were appreciable concentrations of triglyceride and monoglyceride. These must have been derived from endogenously secreted lipid in the case of the tallow fatty acid diet. Thus, the lower digestibility of completely hydrolyzed beef tallow than of conventional beef tallow was not due to an absence of monoglyceride in the intestinal lumen. The proportion of stearic acid in the jejunal digesta was greater than in the dietary lipid, whereas there were lower proportions of palmitic and oleic acids in the jejunal digesta than in the diet; the effect being most pronounced for the tallow free fatty acid diet. The ratio of oleic to palmitic acid in the aqueous phase was less than in the lipid phase suggesting preferential uptake of oleic acid from the micelle by the intestinal mucosa.

scholarly journals Investigation of the Membrane Fluidity Regulation of Fatty Acid Intracellular Distribution by Fluorescence Lifetime Imaging of Novel Polarity Sensitive Fluorescent Derivatives

2021 ◽  
Vol 22 (6) ◽  
pp. 3106
Author(s):  
Giada Bianchetti ◽  
Salome Azoulay-Ginsburg ◽  
Nimrod Yosef Keshet-Levy ◽  
Aviv Malka ◽  
Sofia Zilber ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Membrane Fluidity ◽  
Fluorescence Lifetime ◽  
Intracellular Distribution ◽  
Fluorescence Lifetime Imaging ◽  
Lifetime Imaging ◽  
Fatty Acid Derivatives ◽  
Polarity Sensitive

Free fatty acids are essential structural components of the cell, and their intracellular distribution and effects on membrane organelles have crucial roles in regulating the metabolism, development, and cell cycle of most cell types. Here we engineered novel fluorescent, polarity-sensitive fatty acid derivatives, with the fatty acid aliphatic chain of increasing length (from 12 to 18 carbons). As in the laurdan probe, the lipophilic acyl tail is connected to the environmentally sensitive dimethylaminonaphthalene moiety. The fluorescence lifetime imaging analysis allowed us to monitor the intracellular distribution of the free fatty acids within the cell, and to simultaneously examine how the fluidity and the microviscosity of the membrane environment influence their localization. Each of these probes can thus be used to investigate the membrane fluidity regulation of the correspondent fatty acid intracellular distribution. We observed that, in PC-12 cells, fluorescent sensitive fatty acid derivatives with increased chain length compartmentalize more preferentially in the fluid regions, characterized by a low microviscosity. Moreover, fatty acid derivatives with the longest chain compartmentalize in lipid droplets and lysosomes with characteristic lifetimes, thus making these probes a promising tool for monitoring lipophagy and related events.

scholarly journals The regulation of glyceride synthesis in isolated white-fat cells. The effects of palmitate and lipolytic agents

1972 ◽  
Vol 128 (5) ◽  
pp. 1057-1067 ◽  
Author(s):  
E. D Saggerson
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Fat Cells ◽  
Glyceride Synthesis ◽  
Glucose Incorporation ◽  
High Concentrations ◽  
Stimulation Of

1. 0.5mm-Palmitate stimulated incorporation of [U-14C]glucose into glyceride glycerol and fatty acids in normal fat cells in a manner dependent upon the glucose concentration. 2. In the presence of insulin the incorporation of 5mm-glucose into glyceride fatty acids was increased by concentrations of palmitate, adrenaline and 6-N-2′-O-dibutyryladenosine 3′:5′-cyclic monophosphate up to 0.5mm, 0.5μm and 0.5mm respectively. Higher concentrations of these agents produced progressive decreases in the rate of glucose incorporation into fatty acids. 3. The effects of palmitate and lipolytic agents upon the measured parameters of glucose utilization were similar, suggesting that the effects of lipolytic agents are mediated through increased concentrations of free fatty acids. 4. In fat cells from 24h-starved rats, maximal stimulation of glucose incorporation into fatty acids was achieved with 0.25mm-palmitate. Higher concentrations of palmitate were inhibitory. In fat cells from 72h-starved rats, palmitate only stimulated glucose incorporation into fatty acids at high concentrations of palmitate (1mm and above). 5. The ability of fat cells to incorporate glucose into glyceride glycerol in the presence of palmitate decreased with increasing periods of starvation. 6. It is suggested that low concentrations of free fatty acids stimulate fatty acid synthesis from glucose by increasing the utilization of ATP and cytoplasmic NADH for esterification of these free fatty acids. When esterification of free fatty acids does not keep pace with their provision, inhibition of fatty acid synthesis occurs. Provision of free fatty acids far in excess of the esterification capacity of the cells leads to uncoupling of oxidative phosphorylation and a secondary stimulation of fatty acid synthesis from glucose.

Effect of insulin on free fatty acid uptake by hepatocytes in the duck

1984 ◽  
Vol 102 (3) ◽  
pp. 381-386 ◽  
Author(s):  
R. Gross ◽  
P. Mialhe
Keyword(s):  
Fatty Acids ◽  
Growth Hormone ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Glucose Metabolism ◽  
Free Fatty Acids ◽  
Fatty Acid Uptake ◽  
Acid Uptake ◽  
Low Doses ◽  
Higher Doses

ABSTRACT To elucidate the hypolipacidaemic effect of insulin in ducks, its action on the uptake of free fatty acids (FFA) by duck hepatocytes was determined. At low doses (10 mu./l) insulin stimulated FFA uptake. This effect was not observed with higher doses of insulin (20, 30 and 50 mu./l). Growth hormone at physiological concentrations and corticosterone (14·4 nmol/l) decreased basal activity, probably by reducing glucose metabolism and consequently α-glycerophosphate (α-GP) supply. Insulin was able to reverse the inhibition induced by GH and corticosterone on both FFA uptake and α-GP production. These results therefore suggest that the hypolipacidaemic effect of insulin may be partly mediated by its action on hepatic FFA uptake. J. Endocr. (1984) 102, 381–386

scholarly journals EFFECTS OF CORTISOL ON CULTURED RAT HEART CELLS

1973 ◽  
Vol 57 (1) ◽  
pp. 109-116 ◽  
Author(s):  
J. V. Anastasia ◽  
R. L. McCarl
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Fatty Acid Oxidation ◽  
Growth Medium ◽  
Rat Heart ◽  
Acid Oxidation ◽  
Heart Cells ◽  
Atp Production ◽  
Rat Heart Cells

This paper reports the determination of the ability of rat heart cells in culture to release [14C]palmitate from its triglyceride and to oxidize this fatty acid and free [14C]palmitate to 14CO2 when the cells are actively beating and when they stop beating after aging in culture. In addition, the levels of glucose, glycogen, and ATP were determined to relate the concentration of these metabolites with beating and with cessation of beating. When young rat heart cells in culture are actively beating, they oxidize free fatty acids at a rate parallel with cellular ATP production. Both fatty acid oxidation and ATP production remain constant while the cells continue to beat. Furthermore, glucose is removed from the growth medium by the cells and stored as glycogen. When cultured cells stop beating, a decrease is seen in their ability to oxidize free fatty acids and to release them from their corresponding triglycerides. Concomitant with decreased fatty acid oxidation is a decrease in cellular levels of ATP until beating ceases. Midway between initiation of cultures and cessation of beating the cells begin to mobilize the stored glycogen. When the growth medium is supplemented with cortisol acetate and given to cultures which have ceased to beat, reinitiation of beating occurs. Furthermore, all decreases previously observed in ATP levels, fatty acid oxidation, and esterase activity are restored.

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