scholarly journals The relative significance of acetate and glucose as precursors for lipid synthesis in liver and adipose tissue from ruminants

1967 ◽  
Vol 105 (2) ◽  
pp. 529-536 ◽  
Author(s):  
R. W. Hanson ◽  
F. J. Ballard
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Lipid Synthesis ◽  
Synthetase Activity ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Relative Significance ◽  
Liver Slices ◽  
Rat Adipose Tissue ◽  
Glucose 6 Phosphate Dehydrogenase

1. The incorporation of labelled glucose into lipid by liver slices from sheep and cows is considerably less than that by liver slices from the rat, although oxidation to carbon dioxide occurs to a similar extent. ATP citrate lyase and NADP malate dehydrogenase are inactive in both sheep and cow liver but active in rat liver. The absence of the citrate-cleavage pathway of lipogenesis in ruminant liver has been confirmed by the negligible amounts of C-3 of aspartate incorporated into fatty acids. 2. Considerable amounts of [14C]acetate are incorporated into fatty acids and non-saponifiable lipid in rat and ruminant liver. Acetyl-CoA synthetase, the initial enzyme in the metabolism of acetate, has a high activity in liver from rat and ruminants. 3. In adipose tissue from ruminants more acetate than glucose is converted into lipids, whereas the converse is true in rat adipose tissue. The greater incorporation of [14C]acetate into fatty acids in adipose tissue from the ruminant as compared with the non-ruminant may be caused, in part, by the higher activity of acetyl-CoA synthetase activity in the ruminant. 4. The results suggest that, in both liver and adipose tissue from ruminants, acetate is a more important source of lipid than glucose. 5. Two enzymes of the hexose monophosphate shunt, glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, are active in both tissues and from the three species.

Microsomal glycerolphosphate acyltransferase inactivation by fatty acids

1990 ◽  
Vol 68 (9) ◽  
pp. 1255-1260 ◽  
Author(s):  
V. Durocher ◽  
M. Miller ◽  
M. A. Rodriguez
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Serum Albumin ◽  
Membrane Lipids ◽  
Lipid Synthesis ◽  
Acyltransferase Activity ◽  
Molar Ratios ◽  
Rat Adipose Tissue

Glycerolphosphate acyltransferase activity in microsomes from rat adipose tissue is shown to decrease with time upon incubation with adipose tissue cytosolic fraction. The inactivation can be prevented with serum albumin and seems to be caused by an increase in endogenous free fatty acid as a consequence of the action of cytosolic lipase(s) on the membrane lipids. Similar inactivation can be observed after short incubation of microsomes with oleic acid at micromolar concentrations. Diacylglycerol acyltransferase is also inhibited by oleic acid, although to a lesser degree. In contrast, glucose-6-phosphatase and NADPH – cytochrome reductase activities are not changed. The oleic acid effect appears to occur upon binding to the microsomal membranes and can be prevented by bovine serum albumin at protein/fatty acid molar ratios above one. These results suggest that free fatty acids may be involved in the modulation of triacylglycerol synthetic enzymes.Key words: glycerolphosphate acyltransferase, fatty acids, microsomal enzymes, lipid synthesis.

Acetyl-CoA Regulation, OXPHOS Integrity and Leptin Levels Are Different in Females With Childhood vs Adulthood Onset of Obesity

Endocrinology ◽  
2020 ◽  
Vol 161 (11) ◽  
Author(s):  
Bjorn T Tam ◽  
Jessica Murphy ◽  
Natalie Khor ◽  
Jose A Morais ◽  
Sylvia Santosa
Keyword(s):  
Adipose Tissue ◽  
Subcutaneous Adipose Tissue ◽  
Clinical Manifestations ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Metabolic Intermediate ◽  
Fat Depots ◽  
Regional Body Composition ◽  
Subcutaneous Adipose ◽  
H3 Acetylation

Abstract Although childhood-onset obesity (CO) and adulthood-onset obesity (AO) are known to lead to distinctive clinical manifestations and disease risks, the fundamental differences between them are largely unclear. The aim of the current study is to investigate the fundamental differences between subcutaneous adipose tissue from CO and AO and to identify metabolic differences between abdominal (abSAT) and femoral subcutaneous adipose tissues (feSAT). Total and regional body composition was assessed using dual-energy x-ray absorptiometry (DXA) and computed tomography. Levels of acetyl-CoA, NAD+/NADH, acetyl-CoA network genes, mitochondrial complex abundance, H3 acetylation were determined in biopsied abSAT and feSAT. Serum leptin and adiponectin were measured. Our results showed that acetyl-CoA was higher in subcutaneous adipose tissue from subjects with AO compared with CO. Multiple linear regression revealed that ATP citrate lyase was the only main effect affecting the level of acetyl-CoA. Circulating leptin concentrations was higher in AO. The increased level of acetyl-CoA was strongly associated with histone H3 acetylation, LEP expression in adipose tissue, and circulating leptin in AO. NAD+/NADH was higher in CO; however, abundance of mitochondrial complexes, the complex II:complex V ratio, and the complex IV:complex V ratio were lower in CO, reflecting compromised mitochondrial function in subcutaneous adipose tissue from CO. Moreover, we identified differences in the level of acetyl-CoA and NAD+/NADH ratio between abSAT and feSAT, suggesting that these fat depots may possess different metabolic properties. The fundamental difference in the important metabolic intermediate acetyl-CoA between CO and AO may help us better understand the development of obesity and the pathogenesis of different obesity-related diseases in humans.

Perfusion of rat adipose tissue

1963 ◽  
Vol 205 (2) ◽  
pp. 405-412 ◽  
Author(s):  
André Robert ◽  
Robert O. Scow
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Protein Composition ◽  
Fat Pad ◽  
Edema Formation ◽  
Fatty Acid Release ◽  
Flow Through ◽  
Acid Release ◽  
Rat Adipose Tissue ◽  
Fasted Rats

A technique is described for perfusing the parametrial fat pad of the rat. The rate of flow through the tissue was dependent on temperature, pressure, and the protein composition of the perfusing fluid. The latter also had a pronounced effect on the rate of edema formation in the tissue. The rate of fatty acid release by perfused adipose tissue was affected by the nutritional state of the fat donor and by the composition of the perfusing fluid. Tissue from fed rats did not release fatty acids. Adipose tissue from fasted rats released fatty acids when the tissue was perfused with diluted blood (1.10) or 4% albumin solution but not when perfused with 8% albumin. Perfused tissue released fatty acids at a much faster rate than did incubated tissue. Diluted blood and serum inhibited the release of fatty acids by incubated adipose tissue.

Positional distribution on n−3 fatty acids in triacylglycerols from rat adipose tissue during fish oil feeding

Lipids ◽  
1993 ◽  
Vol 28 (4) ◽  
pp. 279-284 ◽  
Author(s):  
Claude Leray ◽  
Thierry Raclot ◽  
René Groscolas
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fish Oil ◽  
Positional Distribution ◽  
Rat Adipose Tissue

scholarly journals Glycerolipid biosynthesis in rat adipose tissue. Influence of adipose-cell size and site of adipose tissue on triacylglycerol formation in lean and obese rats

1978 ◽  
Vol 170 (1) ◽  
pp. 153-160 ◽  
Author(s):  
S C Jamdar
Keyword(s):  
Adipose Tissue ◽  
Lipid Synthesis ◽  
Fat Depots ◽  
Lipid Formation ◽  
Obese Rats ◽  
Fat Depot ◽  
Esterification Reactions ◽  
Rat Adipose Tissue ◽  
Adipose Organ ◽  
Subcutaneous Adipose

The rates of lipid formation were compared in different fat-depots from lean and obese rats by using [14C]glycerol 3-phosphate, [14C]glucose or [14C]acetate as substrates. In lean animals, subcutaneous adipose tissue showed significantly lower rates of lipid synthesis than did perirenal and gonadal fat-tissue. In obese animals, the rates of lipid synthesis were significantly higher and did not vary from one fat-depot to another. Differences in the rates of lipid formation between lean and obese rats disappeared during dietary restriction of obese animals. The isolated adipocyte preparation did not reflect the true metabolic activity of the adipose organ, since this preparation was mainly derived from smaller adipocytes that were metabolically less active than larger adipocytes. The present study suggests that it is better to use whole tissue preparations to measure lipogenesis and esterification reactions, because these measurements represent the contribution of both larger and smaller adipocytes towards lipid formation.

scholarly journals The Drosophila Citrate Lyase Is Required for Cell Division during Spermatogenesis

Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 206
Author(s):  
Maria Laura Di Giorgio ◽  
Patrizia Morciano ◽  
Elisabetta Bucciarelli ◽  
Antonella Porrazzo ◽  
Francesca Cipressa ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Cell Division ◽  
Histone Acetylation ◽  
Male Meiosis ◽  
Metabolic Enzyme ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Alternative Pathways ◽  
Citrate Lyase ◽  
First Time

The Drosophila melanogaster DmATPCL gene encodes for the human ATP Citrate Lyase (ACL) ortholog, a metabolic enzyme that from citrate generates glucose-derived Acetyl-CoA, which fuels central biochemical reactions such as the synthesis of fatty acids, cholesterol and acetylcholine, and the acetylation of proteins and histones. We had previously reported that, although loss of Drosophila ATPCL reduced levels of Acetyl-CoA, unlike its human counterpart, it does not affect global histone acetylation and gene expression, suggesting that its role in histone acetylation is either partially redundant in Drosophila or compensated by alternative pathways. Here, we describe that depletion of DmATPCL affects spindle organization, cytokinesis, and fusome assembly during male meiosis, revealing an unanticipated role for DmATPCL during spermatogenesis. We also show that DmATPCL mutant meiotic phenotype is in part caused by a reduction of fatty acids, but not of triglycerides or cholesterol, indicating that DmATPCL-derived Acetyl-CoA is predominantly devoted to the biosynthesis of fatty acids during spermatogenesis. Collectively, our results unveil for the first time an involvement for DmATPCL in the regulation of meiotic cell division, which is likely conserved in human cells.

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