Apparent decreased oxidation and turnover of leucine during infusion of medium-chain triglycerides

1985 ◽  
Vol 249 (2) ◽  
pp. E175-E182
Author(s):  
B. Beaufrere ◽  
P. Tessari ◽  
M. Cattalini ◽  
J. Miles ◽  
M. W. Haymond
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Plasma Concentration ◽  
Specific Activity ◽  
Acid Oxidation ◽  
Medium Chain Triglycerides ◽  
Medium Chain ◽  
Protein Sparing ◽  
Pool Model ◽  
Chain Fatty Acids

A potential effector of the protein-sparing adaptation to fasting could be the increased availability of endogenous long-chain fatty acids. Were this hypothesis correct, infusion of medium-chain triglycerides to increase the plasma concentration of medium-chain fatty acids might also result in protein sparing. However, in most in vitro studies in rat muscle, octanoate increases the oxidation of the essential amino acid leucine. Therefore leucine metabolism was assessed with infusions of [3H]leucine and a-[14C]ketoisocaproate ([14C]KIC) before and during an infusion of trioctanoin in conscious dogs. Plasma octanoate increased from less than 30 to 528 microM over the 3 h of infusion. Plasma leucine and KIC concentrations decreased by 65-70% (P less than 0.01) over the first 2 h of infusion. Leucine oxidation, estimated from the expired 14CO2 and the plasma [14C]KIC specific activity, as well as from an open two-pool model, decreased. By use of these isotope models, the rates of leucine coming from and going to protein decreased (P less than 0.05 to P less than 0.01). Interconversion of leucine and KIC estimated from the open two-pool model decreased by 80% (P less than 0.01). These changes were accompanied by a 36% decrease in the plasma concentration of total plasma amino acids. Within the confines of the isotope models employed, these data are consistent with the hypothesis that increased fatty acid oxidation decreases protein turnover and may spare essential amino acids.

scholarly journals Mitochondria1 uncoupling and the isodynamic equivalents of protein, fat and carbohydrate at the level of biochemical energy provision

1985 ◽  
Vol 53 (2) ◽  
pp. 381-389 ◽  
Author(s):  
Geoffrey Livesey
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Energy Conservation ◽  
Full Range ◽  
Coupled System ◽  
Whole Body ◽  
Acid Oxidation ◽  
Food Proteins ◽  
The Mean ◽  
Chain Fatty Acids

1. The effects of uncoupling of mitochondria1 oxidative phosphorylation on the efficiency of energy conservation during oxidation of amino acids, fatty acids, glycerol, glucose and 101 food proteins have been examined in order to compare how uncoupling at coupling site 1 affects energy yields compared with uncoupling at sites 2 + 3 and uncoupling by proton leakage. The effects of uncoupling by each mechanism on the isodynamic equivalents of carbohydrate, fat and protein at the level of cytoplasmic ATP yield have been estimated.2. Energy conservation during amino acid oxidation decreases relative to that for glucose as uncoupling by all three mechanisms increases. This effect is least when uncoupling is at site 1 and is associated with a fall in the isodynamicequivalent for protein: glucose of 4%maximally, and a fall in the cytoplasmic ATP yield for glucose of 25% (15–30% when accounting for uncertainty in the choice of proton stoichiometries).3. Variation in the efficiency of energy conservation for the different amino acids is large for both highly coupled and uncoupled mitochondria but the range of efficiencies for the oxidation of 101 food proteins is relatively small (less than 6% of the mean) for a tightly coupled system. This range increases absolutely (minimally fourfold) and relatively (minimally 44% of the mean value) with severely uncoupled mitochondria but is nearly constant (changes by less than 1% relative to the mean) within the probable physiologically relevant range of uncoupling in the whole body and in the full range of uncoupling at site 1. The rank order position of particular proteins within the range of values is found to change most for gelatin which is oxidized with least energy conservation in a severely (unphysiologically) uncoupled system and most efficiently in a fully coupled system when oxidation of protein is considered to be direct, i.e. not via gluconeogenesis.4. For medium- and long-chain fatty acids, uncoupling at site 1 elevates the efficiency of energy conservation relative to that for glucose (maximally 4%) whereas uncoupling by other mechanisms decreases this relative efficiency. The pattern of effects for short-chain fatty acids resembles that for the amino acids.5. The changes in the isodynamic equivalents of protein:glucose and of fat:glucose are small when uncoupling occurs at site I and tend to cancel for a mixed diet but are additive in the effect on food energy values when uncoupling is by the other mechanisms. Hence changes in the efficiency of oxidative energy coupling at site 1 in association with Luft's disease or dietary changes would result in effects which are of little true dietetic significance on the isodynamic equivalents of nutrients at the level of cytoplasmic ATP yield in vivo.

An improved GLC method for a rapid, simultaneous analysis of both medium chain fatty acids and medium chain triglycerides in plasma

1995 ◽  
Vol 240 (2) ◽  
pp. 195-207 ◽  
Author(s):  
Geltrude Mingrone ◽  
Aldo V. Greco ◽  
Esmeralda Capristo ◽  
Giuseppe Benedetti ◽  
Marco Castagneto ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Simultaneous Analysis ◽  
Medium Chain Triglycerides ◽  
Medium Chain ◽  
Medium Chain Fatty Acids ◽  
Chain Fatty Acids

Nutritional and physiological role of medium-chain triglycerides and medium-chain fatty acids in piglets

2011 ◽  
Vol 12 (1) ◽  
pp. 83-93 ◽  
Author(s):  
J. Zentek ◽  
S. Buchheit-Renko ◽  
F. Ferrara ◽  
W. Vahjen ◽  
A. G. Van Kessel ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Intestinal Microbiota ◽  
Animal Species ◽  
Negative Impact ◽  
Physiological Role ◽  
Feed Additives ◽  
Medium Chain Triglycerides ◽  
Medium Chain ◽  
Medium Chain Fatty Acids ◽  
Chain Fatty Acids

AbstractMedium-chain fatty acids (MCFAs) are found at higher levels in milk lipids of many animal species and in the oil fraction of several plants, including coconuts, palm kernels and certainCupheaspecies. Medium-chain triglycerides (MCTs) and fatty acids are efficiently absorbed and metabolized and are therefore used for piglet nutrition. They may provide instant energy and also have physiological benefits beyond their energetic value contributing to several findings of improved performance in piglet-feeding trials. MCTs are effectively hydrolyzed by gastric and pancreatic lipases in the newborn and suckling young, allowing rapid provision of energy for both enterocytes and intermediary hepatic metabolism. MCFAs affect the composition of the intestinal microbiota and have inhibitory effects on bacterial concentrations in the digesta, mainly onSalmonellaand coliforms. However, most studies have been performedin vitroup to now andin vivodata in pigs are still scarce. Effects on the gut-associated and general immune function have been described in several animal species, but they have been less studied in pigs. The addition of up to 8% of a non-esterified MCFA mixture in feed has been described, but due to the sensory properties this can have a negative impact on feed intake. This may be overcome by using MCTs, allowing dietary inclusion rates up to 15%. Feeding sows with diets containing 15% MCTs resulted in a lower mortality of newborns and better development, particularly of underweight piglets. In conclusion, MCFAs and MCTs offer advantages for the improvement of energy supply and performance of piglets and may stabilize the intestinal microbiota, expanding the spectrum of feed additives supporting piglet health in the post-weaning period.

Mitochondrial and peroxisomal fatty acid oxidation in elasmobranchs

1990 ◽  
Vol 258 (3) ◽  
pp. R756-R762 ◽  
Author(s):  
C. D. Moyes ◽  
L. T. Buck ◽  
P. W. Hochachka
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Salmo Gairdneri ◽  
Acid Oxidation ◽  
Beta Oxidation ◽  
Medium Chain ◽  
Medium Chain Fatty Acids ◽  
Palmitoyl Carnitine ◽  
Red Muscle ◽  
Chain Fatty Acids

In heart and red muscle of dogfish (Squalus acanthias), the maximal activities of the fatty acid catabolizing enzyme carnitine palmitoyltransferase (CPT) are less than 5% the rate in the same tissues of teleosts (carp, Cyprinus carpio; trout, Salmo gairdneri). CPT activities in these tissues of hagfish (Eptatretus stouti) are approximately 10% the rate in teleosts. However, the maximal activities of the beta-oxidation enzyme beta-hydroxyacyl-CoA dehydrogenase (HOAD) in dogfish red muscle and heart are similar to these tissues in the other species. This paradox prompted a more detailed study on the capacity of mitochondria from dogfish cardiac and red skeletal muscles to utilize fatty acids, possibly by a CPT-independent pathway. Free fatty acids were not oxidized by mitochondria from red muscle (hexanoate, octanoate, decanoate, and palmitate) or from heart (octanoate, palmitate). Neither hyposmotic incubation nor addition of 5 mM ATP could stimulate oxidation of octanoate or palmitate in either preparation, suggesting that these tissues have little capacity to oxidize fatty acids by a carnitine-independent pathway. Palmitoyl carnitine oxidation was detectable at very low rates in these mitochondria only with hyposmotic incubation. Octanoyl carnitine was oxidized at greater rates than palmitoyl carnitine, 10% the rate of pyruvate in both tissues, suggesting that medium-chain fatty acids could be physiologically relevant fuels in elasmobranchs if available to heart and red muscle. One potential source of medium-chain fatty acids is hepatic peroxisomal beta-oxidation, which occurs in dogfish liver at maximal activities similar to carp and trout liver. However, based on relative rates of oxidation, it is likely that dogfish heart and red muscle metabolism are fueled primarily by carbohydrate and ketone bodies.

Effects of D-beta-hydroxybutyrate and long- and medium-chain triglycerides on leucine metabolism in humans

1992 ◽  
Vol 262 (3) ◽  
pp. E268-E274 ◽  
Author(s):  
B. Beaufrere ◽  
D. Chassard ◽  
C. Broussolle ◽  
J. P. Riou ◽  
M. Beylot
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Parenteral Nutrition ◽  
Ketone Bodies ◽  
Medium Chain Triglycerides ◽  
Medium Chain ◽  
Leucine Metabolism ◽  
Protein Sparing ◽  
Beta Hydroxybutyrate ◽  
Long Chain

Ketone bodies and/or fatty acids might play a protein-sparing role during prolonged fasting or parenteral nutrition. To assess this problem, we studied whole body leucine metabolism, using L-[1-13C]leucine in normal postabsorptive volunteers who received either long-chain triglycerides (LCT, 0.15 g.kg-1.h-1, 6 subjects), a 50-50 mixture of medium-chain triglycerides (MCT) and LCT (0.15 g.kg-1.h-1, 6 subjects), D-beta-hydroxybutyrate (540 mumol.kg-1.h-1, 6 subjects), or saline (4 subjects). Leucine concentration decreased only with MCT-LCT. Leucine flux decreased by 10-20% from basal in all groups. Leucine oxidation, which was corrected for the contribution to 13CO2 of the 13C natural abundance of the infused substrates, decreased during LCT infusion (0.31 +/- 0.02 to 0.24 +/- 0.01 mumol.kg-1.min-1, P less than 0.01), but was unaffected by MCT-LCT (despite plasma free fatty acid levels similar to those obtained with LCT), D-beta-hydroxybutyrate, or saline infusion. Therefore, 1) the effect of fatty acids on amino acid oxidation is not mediated by ketone bodies, 2) it depends on the fatty acid chain length, 3) long-chain fatty acids but not medium-chain fatty acids could play a protein-sparing role during parenteral nutrition.

Nutritional Values and Health Protective Properties Of Coconut Oil

2020 ◽  
Vol 3 (2) ◽  
pp. 1-12
Author(s):  
Jansen Silalahi
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Coconut Oil ◽  
Medium Chain Triglycerides ◽  
Nutritional Values ◽  
Medium Chain ◽  
Medium Chain Fatty Acids ◽  
Long Chain Triglycerides ◽  
Long Chain ◽  
Chain Fatty Acids

Chemically, fat or oil is a mixture of triacylglycerol molecules, in which glycerol esterified with three fatty acids. Fatty acid is a monocarboxilic acid containing even number of carbon atom started from 4 to 22. Based on the length of fatty acid in triacylglycerol, fats and oils can be classified into two groups; medium chain triglycerides and long chain triglycerides. Coconut oil belongs to medium chain triglycerides oil because it’s fatty acids consist mostly of medium chain fatty acids (C4:0 to C12:0) and dominated by lauric acid (C12:0), hence usually called as lauric oil. In the year of 1950s, coconut oil was claimed that saturated fats, including coconut oil, could increase blood total cholesterol and hence is atherogenic, while unsaturated fats decrease total cholesterol. However, in 1990s, coconut oil was found to be different from the other saturated oils. Coconut oil composed of medium chain fatty acids with high amount of lauric acid. Coconut oil is metabolized differently from long chain triglycerides saturated oil, and therefore coconut oil has numerous beneficial nutritional values and health promotion. Consumption of food rich in medium chain fatty acids reduces the level of body fat and the decrease the risk of heart disease, diabetes, increase mother’s milk quality and active as potential antibacterial agent.  

Sign in / Sign up

Export Citation Format

Share Document