Ankyrin-bound fatty acid turns over rapidly at the erythrocyte plasma membrane.

The membrane skeletal protein ankyrin was shown to be continuously acylated and deacylated with long-chain fatty acids in mature erythrocytes. At least a fraction of the lipid bound to ankyrin turned over rapidly (half-life, approximately 50 min) compared with the polypeptide backbone, which was stable throughout the erythrocyte life. This indicates a regulatory significance of the fatty acid modification for the function of ankyrin.

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Constitutive expression of a saturable transport system for non-esterified fatty acids in Xenopus laevis oocytes

Biochemical Journal ◽

10.1042/bj2970315 ◽

1994 ◽

Vol 297 (2) ◽

pp. 315-319 ◽

Cited By ~ 22

Author(s):

S L Zhou ◽

D Stump ◽

L Isola ◽

P D Berk

Keyword(s):

Fatty Acids ◽

Plasma Membrane ◽

Fatty Acid ◽

Fatty Acid Binding Protein ◽

Xenopus Laevis Oocytes ◽

Long Chain Fatty Acids ◽

Membrane Fatty Acid ◽

Fatty Acid Binding ◽

Acid Binding Protein ◽

Long Chain

In the presence of 150 microM BSA, uptake of [3H]oleate by Xenopus laevis oocytes was a saturable function of the unbound oleate concentration (Vmax. 110 +/- 4 pmol/h per oocyte; Km 193 +/- 11 nM unbound oleate). Oleate uptake was three orders of magnitude faster than that of another test substance, [35S]bromosulphophthalein, and was competitively inhibited by 55 nM unbound palmitate (Vmax. 111 +/- 14 pmol/h per oocyte; Km 424 +/- 63 nM unbound oleate) (P < 0.01). Oleate uptake was also inhibited by antibodies to a 43 kDa rat liver plasma-membrane fatty acid-binding protein, a putative transporter of long-chain fatty acids in mammalian cells; uptake of the medium-chain fatty acid [14C]octanoate was unaffected. Immunofluorescence and immunoblotting demonstrated that the antiserum reacted with a single 43 kDa protein on the oocyte surface. Hence a protein related to the mammalian plasma-membrane fatty acid-binding protein may play a role in saturable uptake of long-chain fatty acids by Xenopus oocytes.

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The effect of intracellular pH on long-chain fatty acid uptake in 3T3-L1 adipocytes: evidence that uptake involves the passive diffusion of protonated long-chain fatty acids across the plasma membrane

Biochemical Journal ◽

10.1042/bj3130487 ◽

1996 ◽

Vol 313 (2) ◽

pp. 487-494 ◽

Cited By ~ 20

Author(s):

Bernardo L. TRIGATTI ◽

Gerhard E. GERBER

Keyword(s):

Fatty Acids ◽

Plasma Membrane ◽

Fatty Acid ◽

Chain Fatty Acid ◽

Long Chain Fatty Acids ◽

Cytoplasmic Ph ◽

Long Chain Fatty Acid ◽

Intact Cells ◽

Fatty Acid Binding ◽

Long Chain

To understand the mechanism of long-chain fatty acid permeation of the plasma membrane in mammalian cells, the effects of changes in the cytoplasmic pH on the internalization of physiologically relevant, submicromolar concentrations of uncomplexed long-chain fatty acids were investigated in 3T3-L1 adipocytes. The acidification of the cytoplasm upon NH4Cl prepulsing of intact cells was accompanied by a rapid reduction of cellular long-chain fatty acid uptake (measured as the total accumulation of [9,10-3H]oleate). This was followed by a slow recovery to normal levels of uptake as the cytoplasmic pH recovered. Conventional filtration assays do not distinguish between fatty acid movement across the plasma membrane and intracellular steps, such as binding to cytoplasmic fatty acid-binding proteins or metabolism. While the in vitro binding of a photoreactive fatty acid, 11-m-diazirinophenoxy[11-3H]undecanoate, to a cytoplasmic fatty acid-binding protein was insensitive to changes in pH from pH 7.5 to 5.5, the in vitro conversion of oleate into oleoyl-CoA by cellular acyl-CoA synthetase decreased dramatically. Therefore, the labelling of the 15 kDa cytoplasmic fatty acid-binding protein in intact cells by the photoreactive fatty acid was used as a more direct measure of the permeation of the probe across the plasma membrane. Acidification of the cytoplasm resulted in an immediate reduction in the labelling of this protein in intact adipocytes. Its photolabelling recovered, however, upon the recovery of the cytoplasmic pH to normal levels. This was due to effects of the cytoplasmic pH on the permeation of the photoreactive fatty acid across the plasma membrane rather than its binding to the 15 kDa protein or metabolism in vivo. This is the first demonstration that the movement of physiologically relevant, submicromolar concentrations of uncomplexed long-chain fatty acids across the plasma membrane of intact cells is coupled to the cytoplasmic pH and suggests that it occurs by the diffusion of the protonated long-chain fatty acid through the lipid bilayer.

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Uptake of long chain fatty acids by human placental choriocarcinoma (BeWo) cells: role of plasma membrane fatty acid-binding protein

The Journal of Lipid Research ◽

10.1016/s0022-2275(20)30040-7 ◽

1997 ◽

Vol 38 (12) ◽

pp. 2558-2568 ◽

Cited By ~ 2

Author(s):

F M Campbell ◽

A M Clohessy ◽

M J Gordon ◽

K R Page ◽

A K Dutta-Roy

Keyword(s):

Fatty Acids ◽

Plasma Membrane ◽

Fatty Acid ◽

Fatty Acid Binding Protein ◽

Long Chain Fatty Acids ◽

Membrane Fatty Acid ◽

Fatty Acid Binding ◽

Acid Binding Protein ◽

Long Chain

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Differential Effects of Fatty Acid Saturation and Chain Length on NASH in Juvenile Iberian Pigs

Current Developments in Nutrition ◽

10.1093/cdn/nzaa050_005 ◽

2020 ◽

Vol 4 (Supplement_2) ◽

pp. 682-682 ◽

Cited By ~ 1

Author(s):

Kayla Dillard ◽

Morgan Coffin ◽

Gabriella Hernandez ◽

Victoria Smith ◽

Catherine Johnson ◽

...

Keyword(s):

Fatty Acids ◽

Body Weight ◽

Fatty Acid ◽

Liver Injury ◽

Olive Oil ◽

Coconut Oil ◽

Long Chain Fatty Acids ◽

Medium Chain ◽

Long Chain ◽

Chain Fatty Acids

Abstract Objectives Non-alcoholic fatty liver disease (NAFLD) represents the major cause of pediatric chronic liver pathology in the United States. The objective of this study was to compare the relative effect of inclusion of isocaloric amounts of saturated medium-chain fatty acids (hydrogenated coconut oil), saturated long-chain fatty acids (lard) and unsaturated long-chain fatty acids (olive oil) on endpoints of NAFLD and insulin resistance. Methods Thirty-eight 15-d-old Iberian pigs were fed 1 of 4 diets containing (g/kg body weight × d) 1) control (CON; n = 8): 0 g fructose, 10.5 g fat, and 187 kcal metabolizable energy (ME), 2) lard (LAR; n = 10): 21.6 g fructose, 17.1 g fat (100% lard) and 299 kcal ME, 3) hydrogenated coconut oil (COCO; n = 10): 21.6 g fructose, 16.9 g fat (42.5% lard and 57.5% coconut oil) and 299 kcal ME, and 4) olive oil (OLV, n = 10): 21.6 g fructose, 17.1 g fat (43.5% lard and 56.5% olive oil) and 299 kcal ME, for 9 consecutive weeks. Body weight was recorded every 3 d. Serum markers of liver injury and dyslipidemia were measured on d 60 at 2 h post feeding, with all other serum measures assessed on d 70. Liver tissue was collected on d 70 for histology, triacylglyceride (TG) quantification, and metabolomics analysis. Results Tissue histology indicated the presence of steatosis in LAR, COCO and OLV compared with CON (P ≤ 0.001), with a further increase in in non-alcoholic steatohepatitis (NASH) in OLV and COCO compared with LAR (P ≤ 0.01). Alanine and aspartate aminotransferases were higher in COCO and OLV (P ≤ 0.01) than CON. All treatment groups had lower liver concentrations of methyl donor's choline and betaine versus CON, while bile acids were differentially changed (P ≤ 0.05). COCO had higher levels of TGs with less carbons (Total carbons < 52) than all other groups (P ≤ 0.05). Several long-chain acylcarnitines involved in fat oxidation were higher in OLV versus all other groups (P ≤ 0.05). Conclusions Inclusion of fats enriched in medium-chain saturated and long-chain unsaturated fatty acids in a high-fructose high-fat diet increased liver injury, compared with fats with a long-chain saturated fatty acid profile. Further research is required to investigate the mechanisms causing this difference in physiological response to these dietary fat sources. Funding Sources ARI, AcornSeekers.

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Effects of cold acclimation on lipid metabolism in adipose tissue

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1961.200.4.847 ◽

1961 ◽

Vol 200 (4) ◽

pp. 847-850 ◽

Cited By ~ 82

Author(s):

Judith K. Patkin ◽

E. J. Masoro

Keyword(s):

Fatty Acids ◽

Adipose Tissue ◽

Fatty Acid ◽

Lipid Metabolism ◽

Cold Acclimation ◽

Long Chain Fatty Acids ◽

Synthetic Capacity ◽

And Control ◽

Long Chain ◽

Chain Fatty Acids

Cold acclimation is known to alter hepatic lipid metabolism. Liver slices from cold-acclimated rats have a greatly depressed capacity to synthesize long-chain fatty acids from acctate-1-C14. Since adipose tissue is the major site of lipogenic activity in the intact animal, its fatty acid synthetic capacity was studied. In contrast to the liver, it was found that adipose tissue from the cold-acclimated rat synthesized three to six times as much long-chain fatty acids per milligram of tissue protein as the adipose tissue from the control rat living at 25°C. Evidence is presented indicating that adipose tissue from cold-acclimated and control rats esterify long-chain fatty acids at the same rate. The ability of adipose tissue to oxidize palmitic acid to CO2 was found to be unaltered by cold acclimation. The fate of the large amount of fatty acid synthesized in the adipose tissue of cold-acclimated rats is discussed.

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Caprenin 1. Digestion, Absorption, and Rearrangement in Thoracic Duct-Cannulated Rats

Journal of the American College of Toxicology ◽

10.3109/10915819109079813 ◽

1991 ◽

Vol 10 (3) ◽

pp. 325-340 ◽

Cited By ~ 29

Author(s):

D. R. Webb ◽

R. A. Sanders

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Female Rats ◽

Acid Uptake ◽

Long Chain Fatty Acids ◽

Male And Female ◽

Medium Chain ◽

Male And Female Rats ◽

Long Chain ◽

Chain Fatty Acids

Caprenin (CAP) is a triglyceride that primarily contains caprylic (C8:0), capric (C10:0), and behenic (C22:0) acids. This study was undertaken to determine whether or not CAP is qualitatively digested, absorbed, and rearranged like other dietary fats and oils that contain these medium-chain and very long-chain fatty acids. In vitro results showed that neat CAP, coconut oil (CO) and peanut oil (PO) were hydrolyzed by porcine pancreatic lipase. All of the neat triglycerides also were digested in vivo by both male and female rats. This was shown by the recovery of significantly more extractable lymphatic fat than with fat-free control animals and by the recovery of orally administered triglyceride-derived fatty acids in lymph triglycerides. However, substantially more PO (74%) and CO (51%) were recovered in lymph relative to CAP (10%). These quantitative differences are consistent with the fatty acid composition of each triglyceride and primary routes of fatty acid uptake. The 24-h lymphatic recovery of CAP-derived C8:0, C10:0, and C22:0 averaged 3.9%, 17.8%, and 11.2%, respectively, for male and female rats. The C8:0 and C10:0 results approximated those obtained with CO (2.0% and 16.3%, respectively). In contrast, the 24-h absorbability of C22:0 in CAP was significantly less than that seen in PO (55.4%). Finally, there was no evidence of significant rearrangement of the positions of fatty acids on glycerol during digestion and absorption. Those fatty acids recovered in lymphatic fat tended to occupy the same glyceride positions that they did in the neat administered oils. However, the lymph fats recovered from all animals dosed with fat emulsions were enriched with endogenous lymph fatty acids. It is concluded that CAP is qualitatively digested, absorbed, and processed like any dietary fat or oil that contains medium-chain and very long-chain fatty acids.

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Up-regulation of the expression of the gene for liver fatty acid-binding protein by long-chain fatty acids

Biochemical Journal ◽

10.1042/bj3190483 ◽

1996 ◽

Vol 319 (2) ◽

pp. 483-487 ◽

Cited By ~ 47

Author(s):

Claire MEUNIER-DURMORT ◽

Hélène POIRIER ◽

Isabelle NIOT ◽

Claude FOREST ◽

Philippe BESNARD

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Fatty Acid Binding Protein ◽

Fold Increase ◽

Long Chain Fatty Acids ◽

Liver Fatty Acid ◽

Fatty Acid Binding ◽

Acid Binding Protein ◽

Fabp Gene ◽

Long Chain

The role of fatty acids in the expression of the gene for liver fatty acid-binding protein (L-FABP) was investigated in the well-differentiated FAO rat hepatoma cell line. Cells were maintained in serum-free medium containing 40 µM BSA/320 µM oleate. Western blot analysis showed that oleate triggered an approx. 4-fold increase in the cytosolic L-FABP level in 16 h. Oleate specifically stimulated L-FABP mRNA in time-dependent and dose-dependent manners with a maximum 7-fold increase at 16 h in FAO cells. Preincubation of FAO cells with cycloheximide prevented the oleate-mediated induction of L-FABP mRNA, showing that protein synthesis was required for the action of fatty acids. Run-on transcription assays demonstrated that the control of L-FABP gene expression by oleate was, at least in part, transcriptional. Palmitic acid, oleic acid, linoleic acid, linolenic acid and arachidonic acid were similarly potent whereas octanoic acid was inefficient. This regulation was also found in normal hepatocytes. Therefore long-chain fatty acids are strong inducers of L-FABP gene expression. FAO cells constitute a useful tool for studying the underlying mechanism of fatty acid action.

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