Seasonal Variation in Plasma Nonesterified Fatty Acids of Lake Sturgeon (Acipenser fulvescens) in the Vicinity of Hydroelectric Facilities

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.

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Aspects of the Energy Metabolism of Lake Sturgeon,Acipenser fulvescens, with Special Emphasis on Lipid and Ketone Body Metabolism

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f90-100 ◽

1990 ◽

Vol 47 (5) ◽

pp. 873-881 ◽

Cited By ~ 64

Author(s):

Thomas D. Singer ◽

Vhundi G. Mahadevappa ◽

James S. Ballantyne

Keyword(s):

Fatty Acid ◽

Lipid Oxidation ◽

Lake Sturgeon ◽

Acipenser Fulvescens ◽

Plasma Nefa ◽

High Turnover ◽

Long Chain Fatty Acid ◽

Nonesterified Fatty Acids ◽

Extrahepatic Tissues ◽

Low Levels

Key enzymes in several metabolic pathways in five tissues were measured in a primitive osteichthyan, the lake sturgeon (Acipenser fulvescens). Levels of nonesterified fatty acids (NEFAs) were measured in the plasma as an indicator of fatty acid mobilization and differential utilization of individual NEFAs as substrates for lipid oxidation. The metabolism of lake sturgeon differs from that of most teleosts studied; it has detectable levels of beta-hydroxy-butyrate dehydrogenase in all tissues, possibly a primitive metabolic feature of vertebrates, subsequently lost in the teleosts. Based on HOAD and CPT activities lipid oxidation in extrahepatic tissues of sturgeon is intermediate between elasmobranch and teleost models. Sturgeon plasma NEFA concentrations are clearly higher than those detected in any elasmobranch, indicating that the acipenserid chondrosteans may be among the first jawed fish to mobilize and transport NEFAs. Oleic acid (18:1,n9) which amounts to 45% of total NEFA content of the plasma may be a preferred substrate of carnitine dependent oxidation. High levels of long chain fatty acid in the plasma may represent a high turnover of eicosanoid precursors. The low levels of LDH in the anoxia tolerant sturgeon may indicate that alternative anaerobic end products, perhaps ethanol, are used to survive under anoxic conditions.

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URINARY CATECHOLAMINE EXCRETION AND PLASMA NEFA CONCENTRATION IN SMALL-FOR-DATE INFANTS

PEDIATRICS ◽

10.1542/peds.47.6.1000 ◽

1971 ◽

Vol 47 (6) ◽

pp. 1000-1009

Author(s):

D. E. Anagnostakis ◽

R. Lardinois

Keyword(s):

Premature Infants ◽

Full Term ◽

Nefa Concentration ◽

Urinary Catecholamine ◽

Neonatal Hypoglycemia ◽

Plasma Nefa ◽

Nonesterified Fatty Acids ◽

Catecholamine Excretion ◽

Fat Stores ◽

Plasma Nefa Concentration

Urinary catecholamine excretion, blood glucose, and plasma nonesterified fatty acids (NEFA) concentration were studied in five full-term, seven premature, and 22 small-for-date (SFD) babies (16 at term and six prematurely born) during the first 8 to 10 days of life. Episodes of hypoglycemia (arbitrarily designed as < 40 mg/100 ml for full term and < 30 mg/100 ml for premature infants) were observed between the second and fifth day of age in 12 SFD babies. During their low blood sugar period, these infants exhibited a significantly higher catecholamine excretion (three- to fourfold for norepinephrine and five- and sixfold for epinephrine) when compared to full term, premature, and "nonhypoglycemic" SFD babies. All SFD babies during the first 2 days of life showed a significantly higher plasma NEFA concentration than the other groups of neonates; among the former, the hypoglycemic ones had a tendency to maintain for a longer period a higher NEFA concentration than the nonhypoglycemic ones. These findings show that SFD babies are capable of reacting to an hypoglycemic stress by mobilizing their fat stores and by releasing catecholamine; therefore, adrenal medullary unresponsiveness cannot be considered as a cause of their transient neonatal hypoglycemia.

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Intramuscular fatty acid metabolism evaluated with stable isotopic tracers

Journal of Applied Physiology ◽

10.1152/jappl.1998.84.5.1674 ◽

1998 ◽

Vol 84 (5) ◽

pp. 1674-1679 ◽

Cited By ~ 45

Author(s):

Zengkui Guo ◽

Michael D. Jensen

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Fatty Acid Metabolism ◽

Acid Metabolism ◽

Isotope Ratio Mass Spectrometry ◽

Isotopic Tracers ◽

Nonesterified Fatty Acids ◽

Stable Isotopic ◽

Fractional Synthesis ◽

Intramuscular Triglyceride

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.

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Improved energy homeostasis of the heart in the metabolic state of exercise

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.2000.279.4.h1490 ◽

2000 ◽

Vol 279 (4) ◽

pp. H1490-H1501 ◽

Cited By ~ 73

Author(s):

Gary W. Goodwin ◽

Heinrich Taegtmeyer ◽

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Fatty Acid Oxidation ◽

Energy Homeostasis ◽

Acid Oxidation ◽

High Fat ◽

Nonesterified Fatty Acids ◽

Malonyl Coa ◽

Metabolic Conditions ◽

High Lactate

We postulate that metabolic conditions that develop systemically during exercise (high blood lactate and high nonesterified fatty acids) are favorable for energy homeostasis of the heart during contractile stimulation. We used working rat hearts perfused at physiological workload and levels of the major energy substrates and compared the metabolic and contractile responses to an acute low-to-high work transition under resting versus exercising systemic metabolic conditions (low vs. high lactate and nonesterified fatty acids in the perfusate). Glycogen preservation, resulting from better maintenance of high-energy phosphates, was a consequence of improved energy homeostasis with high fat and lactate. We explained the result by tighter coupling between workload and total β-oxidation. Total fatty acid oxidation with high fat and lactate reflected increased availability of exogenous and endogenous fats for respiration, as evidenced by increased long-chain fatty acyl-CoA esters (LCFA-CoAs) and by an increased contribution of triglycerides to total β-oxidation. Triglyceride turnover (synthesis and degradation) also appeared to increase. Elevated LCFA-CoAs caused high total β-oxidation despite increased malonyl-CoA. The resulting bottleneck at mitochondrial uptake of LCFA-CoAs stimulated triglyceride synthesis. Our results suggest the following. First, both malonyl-CoA and LCFA-CoAs determine total fatty acid oxidation in heart. Second, concomitant stimulation of peripheral glycolysis and lipolysis should improve cardiac energy homeostasis during exercise. We speculate that high lactate contributes to the salutary effect by bypassing the glycolytic block imposed by fatty acids, acting as an anaplerotic substrate necessary for high tricarbocylic acid cycle flux from fatty acid-derived acetyl-CoA.

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Novel experimental protocol to increase specific plasma nonesterified fatty acids in humans

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00113.2002 ◽

2003 ◽

Vol 284 (1) ◽

pp. E18-E24 ◽

Cited By ~ 9

Author(s):

Carine Beysen ◽

Abigail K. Belcher ◽

Fredrik Karpe ◽

Barbara A. Fielding ◽

Emilio Herrera ◽

...

Keyword(s):

Fatty Acids ◽

Olive Oil ◽

Palm Stearin ◽

Safflower Oil ◽

Experimental Protocol ◽

Plasma Nefa ◽

Heparin Infusion ◽

Nonesterified Fatty Acids ◽

Abundant Fatty Acid ◽

Low Dose Heparin

This study reports a novel protocol to increase plasma monounsaturated, polyunsaturated, and saturated nonesterified fatty acids (NEFA) in eight healthy volunteers (age 29–54 yr, body mass index 23–26 kg/m2). This was achieved by feeding small boluses of fat at different time points (35 g at 0 min and 8 g at 30, 60, 90, 120, 150, 180, and 210 min) in combination with a continuous low-dose heparin infusion. Olive oil, safflower oil, or palm stearin were used to increase monounsaturated, polyunsaturated, or saturated NEFAs, respectively. Plasma NEFA concentrations were increased for 2 h, when fat and heparin were given (olive oil: 745 ± 35 μmol/l; safflower oil: 609 ± 37 μmol/l, and palm stearin: 773 ± 38 μmol/l) compared with the control test (no fat and no heparin: 445 ± 41 μmol/l). During the heparin infusion, 18:1 n-9 was the most abundant fatty acid for the olive oil test compared with 18:2 n-6 for the safflower oil test and 16:0 for the palm stearin test ( P < 0.01). The method described here successfully increases several types of plasma NEFA concentrations and could be used to investigate differential effects of elevated individual NEFAs on metabolic processes.

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The relationships between dietary fatty acids, plasma lipid composition and milk fat secretion in the cow

Journal of Dairy Research ◽

10.1017/s0022029900012899 ◽

1969 ◽

Vol 36 (3) ◽

pp. 383-392 ◽

Cited By ~ 23

Author(s):

J. H. Moore ◽

W. Steele ◽

R. C. Noble

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Stearic Acid ◽

Palmitic Acid ◽

Total Plasma ◽

Milk Fatty Acids ◽

Plasma Fatty Acids ◽

Plasma Triglycerides ◽

Plasma Phospholipids ◽

Concentrate Mixture

SummaryThe effects of the isocaloric replacement of starch in a low-fat concentrate mixture by either 5 or 10% ‘stearic acid’ (85% pure) or by 10% ‘palmitic acid’ (85% pure) on the composition of the plasma lipids were investigated in a feeding experiment with 12 cows in mid-lactation. The concentrate mixtures were given with a high roughage diet that supplied daily 4·4 kg of hay and 2·7 kg of sugar-beet pulp. A study was made of the relationships between the compositions of the plasma and milk lipids.The inclusion of 10% ‘stearic acid’ or 10% ‘palmitic acid’ in the concentrate mixture increased the concentration of total plasma fatty acids. Irrespective of dietary treatment, about 40% of the total plasma fatty acids occurred in the cholesteryl ester fraction, 54% in the phospholipid fraction, 3% in the triglyceride fraction and 3% in the unesterified fatty acid fraction. There was a positive curvilinear relationship between the concentration of unesterified fatty acids in the plasma and the yield of total milk fatty acids.In the plasma triglycerides, the concentrations of 16:0 and 16:1 were decreased and the concentration of 18:0 was increased when the concentrate mixture contained ‘stearic acid’; the concentration of 16:0 was increased and the concentrations of 18:0, 18:1 and 18:2 were decreased when the concentrate mixture contained ‘palmitic acid’. Similar changes were observed in the compositions of the plasma unesterified fatty acids when the cows were given the different diets.In the plasma cholesteryl esters, the concentration of 16:0 was decreased and the concentrations of 18:3 and 20:4 were increased when the concentrate mixture contained stearic acid; the concentrations of 16:1, 18:3 and 20:4 were increased and the concentration of 18:2 was decreased when the diet was supplemented with palmitic acid. The addition of stearic acid to the diet increased the concentration of 18:0, 18:1 and 18:3 in the plasma phospholipids but decreased the concentrations of 16:0, 18:2, 20:3 and 20:4. When the diet contained palmitic acid the concentrations of 16:0, 16:1, 18:1 and 18:3 in the plasma phospholipids were increased but the concentrations of 18:0, 18:2 and 20:3 were decreased.The major fatty acid circulating in the plasma of the cows was 18:2, which accounted for about 45% of the total plasma fatty acids. Only about 0·7% of the total plasma 18:2 occurred in the plasma triglycerides.The results are discussed in relation to the changes in the composition of the milk fatty acids produced by the cows when they were given the experimental diets.

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Plasma Fatty Acid-Binding Protein 4, Nonesterified Fatty Acids, and Incident Diabetes in Older Adults

Diabetes Care ◽

10.2337/dc11-1690 ◽

2012 ◽

Vol 35 (8) ◽

pp. 1701-1707 ◽

Cited By ~ 17

Author(s):

L. Djousse ◽

O. Khawaja ◽

T. M. Bartz ◽

M. L. Biggs ◽

J. H. Ix ◽

...

Keyword(s):

Older Adults ◽

Fatty Acids ◽

Fatty Acid ◽

Fatty Acid Binding Protein ◽

Binding Protein ◽

Incident Diabetes ◽

Plasma Fatty Acid ◽

Fatty Acid Binding ◽

Nonesterified Fatty Acids ◽

Acid Binding Protein

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Mechanism, temporal patterns, and magnitudes of the metabolic responses to the KATP channel agonist diazoxide

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00188.2004 ◽

2005 ◽

Vol 288 (1) ◽

pp. E80-E85 ◽

Cited By ~ 19

Author(s):

Bharathi Raju ◽

Philip E. Cryer

Keyword(s):

Fatty Acids ◽

Insulin Secretion ◽

Fatty Acid ◽

Plasma Glucose ◽

Plasma Insulin ◽

Temporal Patterns ◽

Metabolic Responses ◽

Nonesterified Fatty Acid ◽

Nonesterified Fatty Acids ◽

C Peptide

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.

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PLASMA NON-ESTERIFIED FATTY ACID LEVELS IN HYPOPITUITARY SUBJECTS

Journal of Endocrinology ◽

10.1677/joe.0.0350107 ◽

1966 ◽

Vol 35 (1) ◽

pp. 107-115 ◽

Cited By ~ 2

Author(s):

T. C. B. STAMP

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Oral Administration ◽

Normal Subjects ◽

Control Group ◽

Insulin Administration ◽

Plasma Nefa ◽

Prolonged Fasting ◽

Fat Mobilization ◽

Esterified Fatty Acids

SUMMARY Changes in the plasma levels of non-esterified fatty acids (NEFA) in a group of patients with proven hypopituitarism have been compared with those found in control subjects during prolonged fasting, after the injection of insulin and after the oral administration of glucose with and without the previous administration of insulin. During a 4 hr. prolongation of an overnight fast plasma NEFA levels increased at a significantly slower rate in the patients with hypopituitarism. The intravenous injection of insulin was followed by a prompt fall in NEFA levels in the control group, and by a rapid return to or above original values. The recovery was consistently and markedly impaired in the patients with hypopituitarism and this abnormality differentiated them more clearly from the normal subjects than the abnormality in their plasma sugar response to insulin. The patients with pituitary hypofunction had a flat plasma sugar curve after the oral administration of glucose, but there were only minor differences from the normal plasma NEFA levels. Previous insulin administration impaired glucose tolerance in normal subjects and resulted in a more rapid late return of NEFA levels than after the administration of glucose alone. This late rise in NEFA did not occur in the hypopituitary group. The results obtained support the concept that pituitary integrity is required for normal fat mobilization. The consistency of the changes suggests that tests based on plasma NEFA measurements may provide a useful indirect means of diagnosing pituitary hypofunction.

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