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.

scholarly journals Biochemical actions of vasoactive peptide hormones. Time-synchronized activation of lipolysis and decreased fatty-acid release by bradykinin and angiotensin in the perfused rabbit kidney

1980 ◽  
Vol 192 (1) ◽  
pp. 127-131 ◽  
Author(s):  
M Schwartzman ◽  
A Raz
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Time Lag ◽  
Rabbit Kidney ◽  
Subsequent Decrease ◽  
Fatty Acid Release ◽  
Initial Activation ◽  
Acid Release ◽  
Sequential Processes ◽  
Vasoactive Peptide

Bradykinin and angiotensin administered to the isolated perfused rabbit kidney activate two sequential processes: (1) a selective release of the prostaglandin precursor arachidonate with concomitant partial conversion of the arachidonate into prostaglandin E2; (2) activation of a process that leads to decreased release of all fatty acids in the perfusate. There is a time lag of approx. 1 min between the initial activation of the arachidonate-specific deacylation reaction that is coupled to prostaglandin generation, and the subsequent decrease in the release of all fatty acids. This synchronized cycle provides for instant generation of required amounts of prostaglandins and at the same time serves to conserve cellular arachidonate.

Epinephrine-insulin antagonism on free fatty acid release

1961 ◽  
Vol 201 (5) ◽  
pp. 815-818 ◽  
Author(s):  
John J. Spitzer ◽  
William T. McElroy
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Free Fatty Acids ◽  
Blood Sugar ◽  
Drug Administration ◽  
Hepatic Uptake ◽  
Fatty Acid Release ◽  
Plasma Ffa ◽  
Acid Release

The effects of epinephrine or norepinephrine were studied in dogs receiving insulin plus glucose prior to and during administration of the amine. Epinephrine caused a significantly smaller elevation of free fatty acids (FFA) with than without insulin plus glucose administration. Blood sugar responses were quantitatively similar. Epinephrine increased both hepatic uptake of FFA and hepatic release of glucose; these changes were similar to the ones found previously in dogs not receiving insulin plus glucose. The action of norepinephrine on elevating plasma FFA was only slightly and not significantly affected by the administration of insulin plus glucose. When the order of drug administration was reversed, infusion of insulin plus glucose lowered plasma FFA levels and hepatic FFA uptake in animals already receiving either epinephrine or nonepinephrine.

Eicosapentaenoic and dihomo gamma linolenic acid metabolism by cultured rat mesangial cells

1989 ◽  
Vol 256 (1) ◽  
pp. C101-C108 ◽  
Author(s):  
L. A. Scharschmidt ◽  
N. B. Gibbons ◽  
R. Neuwirth
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Acid Metabolism ◽  
Mesangial Cells ◽  
Gamma Linolenic Acid ◽  
Significant Extent ◽  
Glomerular Function ◽  
Fatty Acid Release ◽  
Acid Release ◽  
Stimulation Of

To better understand the effects of dietary fatty acid manipulations on glomerular function, we compared mesangial incorporation, release, and metabolism of arachidonic (AA), eicosapentaenoic (EPA), and dihomo gamma linolenic (DHG) acids. We found marked differences in mesangial handling of these fatty acids. AA was incorporated into lipids of mesangial cells much more rapidly than EPA or DHG. Ionophore-induced stimulation of fatty acid release from mesangial cells prelabeled with [14C]AA, [14C]EPA, or [14C]DHG caused a release of labeled AA greater than DHG much less than EPA, respectively. Preloading mesangial cells with DHG or EPA for 24 h reduced subsequent basal, ionophore-, and hormone-stimulated prostaglandin E2 (PGE2) synthesis. Finally, unlike AA, neither EPA nor DHG was converted to a significant extent by mesangial cyclooxygenase or lipoxygenase. Thus the mesangial metabolism of DHG and EPA differs both quantitatively and qualitatively from that of AA. Furthermore, EPA and DHG inhibit metabolism of AA at the level of mesangial cyclooxygenase.

High resting triacylglycerol turnover of rainbow trout exceeds the energy requirements of endurance swimming

2008 ◽  
Vol 295 (1) ◽  
pp. R309-R315 ◽  
Author(s):  
Leonardo Magnoni ◽  
Eric Vaillancourt ◽  
Jean-Michel Weber
Keyword(s):  
Fatty Acids ◽  
Rainbow Trout ◽  
Turnover Rate ◽  
Energy Requirements ◽  
Membrane Phospholipids ◽  
Very Low Density Lipoproteins ◽  
Homeoviscous Adaptation ◽  
Versatile Tool ◽  
Infusion Method

Fish may use lipoproteins instead of albumin-bound fatty acids to fuel endurance exercise, but lipoprotein kinetics have never been measured in ectotherms. In vivo bolus injections of labeled very-low-density lipoproteins (3H-VLDL labeled in vivo from donor fish) and continuous infusions of Intralipid (3H-labeled artificial emulsion) were used to investigate the effects of prolonged exercise (6 h at 1.5 body length/s) and heparin (600 U/kg) on the turnover rate of circulating triacylglycerol (TAG) in rainbow trout. We hypothesized that swimming would stimulate TAG turnover rate to fuel working muscles and that heparin would reduce flux by releasing lipoprotein lipase (LPL) from endothelial cells. Results from both tracer methods show that the baseline TAG turnover rate of trout ranges from 24 to 49 μmol TAG·kg−1·min−1 and exceeds all values measured to date in endotherms. More important, this high resting turnover rate is not stimulated during swimming, because it can already cover several times the energy requirements of locomotion. The fact that heparin causes a 50% decrease in baseline TAG turnover rate suggests that fish LPL must be bound to the endothelium for normal tissue uptake of fatty acids supplied by lipoproteins, as in mammals. We propose that the high resting TAG turnover rate of rainbow trout could be needed by ectotherms for rapid restructuring of membrane phospholipids. The continuous tracer infusion method implemented here could be a versatile tool to investigate the potential role of lipoproteins in providing fatty acids for rapid homeoviscous adaptation.

Action of phospholipases A2 and C on free fatty acid release during complete ischemia in rat neocortex

1992 ◽  
Vol 76 (4) ◽  
pp. 648-651 ◽  
Author(s):  
Atsushi Umemura ◽  
Hideo Mabe ◽  
Hajime Nagai ◽  
Fumihiko sugino
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Free Fatty Acids ◽  
Phospholipase C ◽  
Phenylmethylsulfonyl Fluoride ◽  
Content Type ◽  
Rat Neocortex ◽  
Fatty Acid Release ◽  
Acid Release

✓ The levels of brain free fatty acids rapidly increase after the onset of ischemia. The purpose of this study was to investigate the action of phospholipases A2 and C during complete ischemia based on the effects of a phospholipase C inhibitor (phenylmethylsulfonyl fluoride) and the N-methyl-D-aspartate antagonist MK-801 on the release of free fatty acids in rat neocortex. Complete brain ischemia was induced in rats with cardiac arrest by intracardiac injection of KC1. Free fatty acid levels in the neocortex were measured 0, 2, 4, and 8 minutes after cardiac arrest. Phenylmethylsulfonyl fluoride inhibited the release of free fatty acids primarily from phosphatidylinositol during the first 2 minutes of ischemia and from phosphatidylcholine and phosphatidylethanolamine at 4 to 8 minutes of ischemia. Conversely, MK-801 inhibited free fatty acid release mainly from phosphatidylcholine and phosphatidylethanolamine at 2 to 4 minutes of ischemia. These results indicate that the release of free fatty acids during the first 2 minutes of ischemia can be attributed mostly to the action of phospholipase C, and that the activation of phospholipase C further influences the activation of phospholipase A2 in the subsequent course, while phospholipase A2 predominantly acts after 2 minutes of ischemia.

scholarly journals Studies on lipid digestion in the preruminant calf

1978 ◽  
Vol 40 (1) ◽  
pp. 125-131 ◽  
Author(s):  
J. D. Edwards-Webb ◽  
S. Y. Thompson
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Butyric Acid ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Esterified Fatty Acids ◽  
Chain Fatty Acids

1. The lipolysis of cow's milk fat by salivary lipase (EC 3.1.1.3) in the preruminant calf has been studied in vitro by a simulated abomasal digestion, and also in vivo by examining the abomasal effluent collected over 12 h after giving whole milk to a calf.2. In the in vitro experiment the liquid drained from the clot contained a higher proportion of short-chain fatty acids than the abomasal effluent in the in vivo experiment. This was considered to indicate the absorption of short-chain free fatty acids from within the abomasum.3. Preferential release of short-chain fatty acids both in vitro and in vivo was observed.4. The outflow of butyric acid from the abomasum of the calf was initially rapid, but had levelled off at approximately 6 h, whereas the outflow of a typical long-chain fatty acid (palmitic) was fairly constant over the 12 h.Butyric acid predominated in the free fatty acids of abomasal effluent 0.5 h after feeding (668 mmol/mol total free fatty acids) but had become a minor component by 12 h (15 mmol/mol total free fatty acids).5. The mean amounts of free and esterified fatty acids (mmol/mol fatty acid ingested) present in the abomasal effluent from the 12 h collection period were: triglyceride 465, diglyceride 215, monoglyceride 68, free fatty acid 252. These values showed that only one-third of esterified fatty acids ingested are lipolysed to absorbable products by salivary lipase.

scholarly journals The response of adipocyte glucose metabolism and fatty acid release to adenosine deaminase, insulin and perifusion. Investigation of intermediary metabolism by perifusion

1988 ◽  
Vol 251 (3) ◽  
pp. 733-737
Author(s):  
R D Harper
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Glucose Metabolism ◽  
Adenosine Deaminase ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Intermediary Metabolism ◽  
Glucose Incorporation ◽  
Fatty Acid Release ◽  
Acid Release

Adipocytes incubated with adenosine deaminase (ADA) showed: (1) increased amounts of fatty acids in the medium; (2) increased glucose incorporation into acylglycerol glycerol; (3) decreased glucose incorporation into acylglycerol fatty acids; (4) a co-ordinate decrease in the sensitivity of lipolysis and glucose incorporation into acylglycerol to insulin; (5) similar effects on glucose incorporations in perifused and normal incubations. The decrease in fatty acid synthesis by perfusion was found to be dependent on the presence of insulin or fatty acids, and independent of the effects of ADA. The significance of the effects of perifusion, ADA and insulin are discussed in relation to effects of fatty acids.

scholarly journals Free fatty acid release from vegetable and bovine milk fat-based infant formulas and human milk during two-phase in vitro digestion

2019 ◽  
Vol 10 (4) ◽  
pp. 2102-2113 ◽  
Author(s):  
Jeske H. J. Hageman ◽  
Jaap Keijer ◽  
Trine Kastrup Dalsgaard ◽  
Lara W. Zeper ◽  
Frédéric Carrière ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Milk Fat ◽  
Bovine Milk ◽  
In Vitro Digestion ◽  
Infant Formulas ◽  
Two Phase ◽  
Fatty Acid Release ◽  
Acid Release

The profile of fatty acids released during in vitro digestion of vegetable and bovine milk fat-based infant formula differ.

scholarly journals Interactions in vivo between oxidation of non-esterified fatty acids and gluconeogenesis in the newborn rat

1979 ◽  
Vol 182 (2) ◽  
pp. 593-598 ◽  
Author(s):  
P Ferré ◽  
J P Pégorier ◽  
D H Williamson ◽  
J Girard
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Pyruvate Carboxylase ◽  
Acid Oxidation ◽  
Newborn Rat ◽  
Esterified Fatty Acids ◽  
Metabolic Interactions ◽  
Hepatic Fatty Acid Oxidation

Metabolic interactions between fatty acid oxidation and gluconeogenesis were investigated in vivo in 16h-old newborn rats under various nutritional states. As the newborn rat has no white adipose tissue, starvation from birth induces a low rate of hepatic fatty acid oxidation. Hepatic gluconeogenesis in inhibited in the starved newborn rat when compared with the suckling rat, which receives fatty acids through the milk, at the steps catalysed by pyruvate carboxylase and glyceraldehyde 3-phosphate dehydrogenase. These inhibitions are rapidly reversed by triacylglycerol feeding. Inhibition of fatty acid oxidation by pent-4-enoate in the suckling animal mimics the effect of starvation on the pattern of hepatic gluconeogenic metabolites. It is concluded that, in the newborn rat in vivo, hepatic fatty acids oxidation can increase the gluconeogenic flux by providing the acetyl-CoA necessary for the reaction catalysed by pyruvate carboxylase and the reducing equivalents (NADH) to displace the reversible reaction catalysed by glyceraldehyde 3-phosphate dehydrogenase in the direction of gluconeogenesis.

Sign in / Sign up

Export Citation Format

Share Document