scholarly journals Preferential distribution of non-esterified fatty acids to phosphatidylcholine in the neonatal mammalian myocardium

1984 ◽  
Vol 224 (2) ◽  
pp. 651-659 ◽  
Author(s):  
N A Schroedl ◽  
C R Hartzell

Non-esterified fatty acids are used to a limited extent as an energy source in the newborn-mammalian heart. Therefore additional roles for palmitic and oleic acids during this early period of growth and development were investigated in the cultured neonatal-rat heart cell model system. Our results indicate significant differences in nonesterified-fatty-acid metabolism exist in this system in comparison with the adult rat or embryonic chick heart. Initial rates of depletion of palmitate and oleate from serum-free growth medium by heart cells obtained from 2-day-old rats and maintained in culture for 10 or 11 days were 111 +/- 2 and 115 +/- 3 pmol/min per mg of protein respectively. In serum-containing medium, the initial depletion rates were 103 +/- 3 and 122 +/- 4 pmol/min per mg of protein respectively, when endogenous serum nonesterified-fatty-acid concentrations were included in rate calculations. Less than 1% of the intracellularly incorporated fatty acids were found in aqueous products at any time. After 25 h, 15.5% of the initial palmitate was deposited intracellularly in the phosphatidylcholine lipid fraction, 4.2% in the triacylglycerol + fatty-acid-ester fraction and 3.1% in the sphingomyelin fraction. These results contradict the classical view, based on findings with the lipid-dependent adult heart, that exogenous nonesterified fatty acids are directed intracellularly primarily to pathways of oxidation or to storage as triacylglycerol. More importantly, it underscores the significance of exogenous non-esterified fatty acids in membrane biosynthesis of the developing mammalian heart. Included here is a new method for one-dimensional t.l.c. separation of metabolically important polar lipids.

2005 ◽  
Vol 288 (1) ◽  
pp. E80-E85 ◽  
Author(s):  
Bharathi Raju ◽  
Philip E. Cryer

To assess the mechanism, temporal patterns, and magnitudes of the metabolic responses to the ATP-dependent potassium channel agonist diazoxide, neuroendocrine and metabolic responses to intravenous diazoxide (saline, 1.0 and 2.0 mg/kg) and oral diazoxide (placebo, 4.0 and 6.0 mg/kg) were assessed in healthy young adults. Intravenous diazoxide produced rapid, but transient, decrements ( P = 0.0023) in plasma insulin (e.g., nadirs of 2.8 ± 0.5 and 1.8 ± 0.3 μU/ml compared with 7.0 ± 1.0 μU/ml after saline at 4.0–7.5 min) and C-peptide ( P = 0.0228) associated with dose-related increments in plasma glucose ( P = 0.0044) and serum nonesterified fatty acids ( P < 0.0001). After oral diazoxide, plasma insulin appeared to decline, as did C-peptide, again associated with dose-related increments in plasma glucose ( P < 0.0001) and serum nonesterified fatty acids ( P = 0.0141). Plasma glucagon, as well as cortisol and growth hormone, was not altered. Plasma epinephrine increased ( P = 0.0215) slightly only after intravenous diazoxide. There were dose-related increments in plasma norepinephrine ( P = 0.0038 and P = 0.0005, respectively), undoubtedly reflecting a compensatory sympathetic neural response to vasodilation produced by diazoxide, but these would not raise plasma glucose or serum nonesterified fatty acid levels. Thus selective suppression of insulin secretion, without stimulation of glucagon secretion, raised plasma glucose and serum nonesterified fatty acid concentrations. These findings define the temporal patterns and magnitudes of the metabolic responses to diazoxide and underscore the primacy of regulated insulin secretion in the physiological regulation of postabsorptive carbohydrate and lipid metabolism.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Cassiano Felippe Gonçalves de Albuquerque ◽  
Patrícia Burth ◽  
Mauricio Younes Ibrahim ◽  
Diogo Gomes Garcia ◽  
Patrícia Torres Bozza ◽  
...  

Although exerting valuable functions in living organisms, nonesterified fatty acids (NEFAs) can be toxic to cells. Increased blood concentration of oleic acid (OLA) and other fatty acids is detected in many pathological conditions. In sepsis and leptospirosis, high plasma levels of NEFA and low albumin concentrations are correlated to the disease severity. Surprisingly, 24 h after intravenous or intragastric administration of OLA, main NEFA levels (OLA inclusive) were dose dependently decreased. However, lung injury was detected in intravenously treated mice, and highest dose killed all mice. When administered by the enteral route, OLA was not toxic in any tested conditions. Results indicate that OLA has important regulatory properties on fatty acid metabolism, possibly lowering circulating fatty acid through activation of peroxisome proliferator-activated receptors. The significant reduction in blood NEFA levels detected after OLA enteral administration can contribute to the already known health benefits brought about by unsaturated-fatty-acid-enriched diets.


2009 ◽  
Vol 57 (4) ◽  
pp. 590-594 ◽  
Author(s):  
Gloria Lena Vega ◽  
Fredrick L. Dunn ◽  
Scott M. Grundy

BackgroundSeveral studies suggest that increased nonesterified fatty acid flux and increased de novo lipogenesis may contribute to hypertriglyceridemia, but few studies have examined fatty acid oxidation as a factor.RationaleEndogenous hypertriglyceridemia (increased very low density lipoprotein triglyceride) could result from (a) re-esterification of excess nonesterified fatty acids entering the liver, (b) activation of hepatic lipogenesis, and/or (c) defective oxidation of hepatic fatty acids leading to greater triglyceride synthesis. Therefore, this study used plasma levels of 3-hydroxybutyrate as a marker for fatty acid oxidation. The study was carried out in hypertriglyceridemic and normotriglyceridemic subjects under 3 conditions: (a) in the fasting state, (b) after a fatty meal that should enhance fatty acid oxidation, and (c) after an oxandrolone challenge, which we recently showed increases fatty acid oxidation.ResultsIn the fasting state, 3-hydroxybutyrate concentrations in hypertriglyceridemic patients were only 53% of levels in normotriglyceridemic subjects. After a fatty meal, moderate increases in 3-hydroxybutyrate were observed, but values for patients with hypertriglceridemia remained 62% of the levels in the normotriglyceridemic group. A similar pattern of response was observed with oxandrolone challenge. There were no significant changes in fasting or postprandial levels of nonesterfified fatty acids, glycerol, or triglycerides before and during the oxandrolone challenge.ConclusionPatients with endogenous hypertriglyceridemia seem to have a defect in fatty acid oxidation as indicated by reduced levels of 3-hydroxybutyrate. This defect was observed during fasting, postprandially, and during oxandrolone challenge. We propose that this defect contributes to the development of hypertriglyceridemia.


1993 ◽  
Vol 50 (11) ◽  
pp. 2440-2447 ◽  
Author(s):  
R. S. McKinley ◽  
T. D. Singer ◽  
J. S. Ballantyne ◽  
G. Power

To establish the effects of hydroelectric generation on the health of lake sturgeon (Acipenser fulvescens), seasonal variations in plasma nonesterified fatty acids (NEFAs) upstream and downstream from hydroelectric stations were measured over a 2-yr period. Plasma NEFA profiles were also compared up- and downstream of the stations for differences in utilization of individual NEFA species as substrates for lipid oxidation. Significantly higher levels of total plasma NEFA were found in lake sturgeon upstream (2355 ± 395.9 nmol/mL) compared with those downstream (798 ± 133.5 nmol/mL) of the generating stations during the spring. The NEFA profiles for several key fatty acid species differed significantly among seasons up- and downstream of the facilities. In particular, during spring and summer, the levels of oleic acid (18:1n9) were highest upstream of the stations and levels of a polyunsaturated fatty acid, docosahexaenoic acid (22:6n3), were higher below rather than above the stations. The differences in plasma NEFA concentration may be attributed to altered nutritional status due to the varying flow regime located downstream of the hydroelectric stations.


1970 ◽  
Vol 46 (2) ◽  
pp. 342-353 ◽  
Author(s):  
Samuel W. Cushman

Pinocytic activity in the adipose cell has been examined by measuring the uptake of colloidal gold. Pinocytic activity occurs in the isolated adipose cell under all experimental conditions; a portion of the vesicular elements of the cell can be identified by electron microscopy as pinocytic in origin. The isolated adipose cell appears to take up serum albumin by pinocytosis. Pinocytic activity in the isolated adipose cell is enhanced by epinephrine, but not by insulin. The relationship between pinocytosis and the metabolic activity of the adipose cell has been studied by measuring simultaneously the uptake of radioactive colloidal gold, the incorporation of 14C-counts from U-glucose-14C into CO2, total lipid, triglyceride glycerol and triglyceride fatty acids, and the release of nonesterified fatty acids in the absence of hormones and in the presence of insulin or epinephrine. Correlations between hormone-produced alterations in lipid metabolism and in pinocytic activity suggest that intracellular nonesterified fatty acid levels are a factor in the regulation of both the cell's pinocytic activity and its metabolism and that pinocytosis in the adipose cell functions in the extracellular-intracellular transport of nonesterified fatty acids.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 232-233
Author(s):  
Ekaterina Karpova ◽  
Ludmila Chizhova ◽  
Eugenia Surzhikova

Abstract The early period of postnatal ontogeny of sheep is characterized by a variety of metabolic processes that result in the formation and consolidation of a certain type of metabolism. A special role is played by lipids, which together with proteins and carbohydrates constitute the bulk of organic compounds, cells and the organism as a whole. The purpose of this research was to study the polymorphism of CAST and GH genes as well as its association with the fatty acid composition of blood plasma lipids in lambs. The content of fatty acids was determined by gas-liquid chromatography in the form of methyl esters. From the data obtained, it follows that in all studied ontogeny periods the peripheral blood of sheep with CASTNN and CASTMM genotypes had a higher concentration of fatty acids such as palmitic, stearic, linoleic, and arachidonic acids. The content is as follows: 27.58, 45.40, 3.16, 0.28% vs. 26.21, 45.31, 3.62, 0.18% at the age of 2 months; 25.07, 43.25, 6.05, 1.74% vs. 23.24, 38.76, 6.49, 1.32% at the age of 4 months; 20.64, 22.26, 14.17, 3.38% vs. 17.64, 19.91, 15.07, 2.46% at the age of 8 months (P ˂ 0.05), (P ˂ 0.01). Studies of blood lipid composition of GHBBand GHAA genotype carriers showed that palmitic, stearic, linoleic, and arachidonic acids were dominant: 27.95, 27.96, 19.04% vs. 26.08, 23.88, 17.56% at the age of 2 months, 46.87, 39.87, 22.37% vs. 3.24, 6.87, 15.56% at the age of 4 months; 0.45, 1.68, 3.81% vs. 0.29, 1.29, 3.19% at the age of 8 months (P ˂ 0.05), (P ˂ 0.01). Thus, this study emphasizes that there is a close relationship between the ratio of fatty acids in total blood lipids in lambs and the intensity of growth and development, ensuring and controlling the direction of biochemical processes in the growth and development of young sheep.


1973 ◽  
Vol 57 (1) ◽  
pp. 109-116 ◽  
Author(s):  
J. V. Anastasia ◽  
R. L. McCarl

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.


1998 ◽  
Vol 84 (5) ◽  
pp. 1674-1679 ◽  
Author(s):  
Zengkui Guo ◽  
Michael D. Jensen

We evaluated the applicability of stable isotopic tracers to the study of intramuscular fatty acid metabolism by infusing both [U-13C]palmitate and [1-13C]oleate intravenously for 4 h into fasted conscious rats. Skeletal muscles were sequentially biopsied, and the concentration and13C enrichment of fatty acids were measured by gas chromatography/combustion/isotope ratio mass spectrometry. Throughout the study, the13C enrichment of plasma palmitate and oleate remained substantially greater than intramuscular nonesterified palmitate and oleate enrichment, which in turn was greater than intramuscular triglyceride palmitate and oleate enrichment. Fractional synthesis rates of intramuscular triglycerides in gastrocnemius and soleus were 0.267 ± 0.075 and 0.100 ± 0.030/h ( P = 0.04), respectively, as determined by using [U-13C]palmitate, and were 0.278 ± 0.049 and 0.075 ± 0.013/h ( P = 0.02), respectively, by using [1-13C]oleate. We conclude that plasma free fatty acids are a source for intramuscular triglycerides and nonesterified fatty acids; the latter are likely the synthetic precursors of the former. Uniformly and singly labeled [13C]fatty acid tracers will provide an important tool to study intramuscular fatty acid and triglyceride metabolism.


2000 ◽  
Vol 278 (3) ◽  
pp. R663-R668 ◽  
Author(s):  
Hershel Raff ◽  
Eric D. Bruder ◽  
Barbara M. Jankowski ◽  
Theodore L. Goodfriend

Neonatal hypoxia increases aldosterone production and plasma lipids. Because fatty acids can inhibit aldosterone synthesis, we hypothesized that increases in plasma lipids restrain aldosteronogenesis in the hypoxic neonate. We exposed rats to 7 days of hypoxia from birth to 7 days of age (suckling) or from 28 to 35 days of age (weaned at day 21). Plasma was analyzed for lipid content, and steroidogenesis was studied in dispersed whole adrenal glands untreated and treated to wash away lipids. Hypoxia increased plasma cholesterol, triglycerides, and nonesterified fatty acids in the suckling neonatal rat only. Washing away lipids increased aldosterone production in cells from 7-day-old rats exposed to hypoxia, but not in cells from normoxic 7-day-old rats or from normoxic or hypoxic 35-day-old rats. Addition of oleic or linolenic acid to washed cells inhibited both aldosterone and corticosterone production, although cells from hypoxic 7-day-old rats were less sensitive. We conclude that hypoxia induces hyperlipidemia in the suckling neonate and that elevated nonesterified fatty acids inhibit aldosteronogenesis.


1997 ◽  
Vol 273 (3) ◽  
pp. E644 ◽  
Author(s):  
R E Pratley ◽  
M Nicolson ◽  
C Bogardus ◽  
E Ravussin

Leptin is believed to play a role in the regulation of energy balance, but little is known about factors influencing plasma leptin concentrations. To determine the effect of short-term changes in energy balance, we measured plasma leptin concentrations as well as plasma glucose, insulin, triglyceride, nonesterified fatty acid concentrations, and metabolic rate in response to a standard test meal followed by a 24-h fast in 21 healthy Pima Indians. Plasma leptin concentrations decreased by 8% (P < 0.05) 2-4 h after the test meal. They returned to baseline 6-12 h after the subjects ate, then subsequently decreased, and, by the end of the fast, were an average of 37% below baseline (P < 0.0001). Changes in plasma leptin concentrations did not correlate with changes in plasma glucose, insulin, triglyceride, or nonesterified fatty acid concentrations or with changes in metabolic rate. The results of this study indicate that plasma leptin concentrations decrease in response to short-term energy restriction. These changes were not due to changes in glucose, insulin, triglycerides, or nonesterified fatty acids, nor did they relate to changes in metabolic rate. The decrease in plasma leptin concentrations with fasting may be an important homeostatic response to an energy deficit, stimulating food intake and thus restoring energy balance.


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