scholarly journals Membrane fatty acid composition of rat skeletal muscle is most responsive to the balance of dietary n-3 and n-6 PUFA

2009 ◽  
Vol 103 (4) ◽  
pp. 522-529 ◽  
Author(s):  
Sarah K. Abbott ◽  
Paul L. Else ◽  
A. J. Hulbert
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Fatty Acid Profile ◽  
Acid Composition ◽  
Essential Fatty Acids ◽  
Muscle Membrane ◽  
Rat Skeletal Muscle ◽  
Muscle Composition

The present study quantifies the relationships between diet fatty acid profile and fatty acid composition of rat skeletal muscle phospholipids. Young adult male Sprague–Dawley rats were fed, for 8 weeks, on one of twelve moderate-fat diets (25 % of total energy) differing only in fatty acid profile. SFA content ranged from 8–88 % of total fatty acids, MUFA 6–65 %, total PUFA 4–81 %, n-6 PUFA 3–70 % and n-3 PUFA 1–70 %. Diet PUFA included only essential fatty acids 18 : 2n-6 and 18 : 3n-3. The balance between n-3 and n-6 PUFA (PUFA balance) in the diet ranged from 1 : 99 to 86 : 14 % n-3 PUFA:n-6 PUFA. The slope of muscle phospholipid composition plotted against diet composition quantifies the response of muscle membrane composition to dietary fat (0, no response; 1, complete conformity with diet). The resulting slopes were 0·02 (SFA), 0·10 (PUFA), 0·11 (MUFA), 0·14 (n-3 PUFA) and 0·23 (n-6 PUFA). The response to PUFA balance was biphasic with a slope of 0·98 below 10 % diet PUFA balance and 0·16 above 10 %. Thus, low diet PUFA balance has greater influence on muscle composition than 18-carbon n-3 or n-6 PUFA individually. Equations provided may allow prediction of muscle composition for other diet studies. Diet PUFA balance dramatically affects muscle 20 : 4n-6 and 22 : 6n-3. This may have significant implications for some disease states in human subjects.

Skeletal muscle phosphatidylcholine fatty acids and insulin sensitivity in normal humans

1998 ◽  
Vol 275 (4) ◽  
pp. E665-E670 ◽  
Author(s):  
John N. Clore ◽  
Jing Li ◽  
Ranjodh Gill ◽  
Shona Gupta ◽  
Robert Spencer ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Insulin Sensitivity ◽  
Acid Composition ◽  
Vastus Lateralis ◽  
Muscle Membrane ◽  
Membrane Phospholipids ◽  
Normal Humans

The fatty acid composition of skeletal muscle membrane phospholipids (PL) is known to influence insulin responsiveness in humans. However, the contribution of the major PL of the outer (phosphatidylcholine, PC) and inner (phosphatidylethanolamine, PE) layers of the sarcolemma to insulin sensitivity is not known. Fatty acid composition of PC and PE from biopsies of vastus lateralis from 27 normal men and women were correlated with insulin sensitivity determined by the hyperinsulinemic euglycemic clamp technique at insulin infusion rates of 0.4, 1.0, and 10.0 mU ⋅ kg−1 ⋅ min−1. Significant variation in the half-maximal insulin concentration (ED50) was observed in the normal volunteers (range 24.0–146.0 μU/ml), which correlated directly with fasting plasma insulin ( r = 0.75, P < 0.0001). ED50 was inversely correlated with the degree of membrane unsaturation (C20-C22polyunsaturated fatty acids; r = 0.58, P < 0.01) and directly correlated with fatty acid elongation (ratio of 16:0 to 18:0, r = 0.45, P < 0.05) in PC. However, no relationship between fatty acid composition and insulin sensitivity was observed in PE (NS). These studies suggest that the fatty acid composition of PC may be of particular importance in the relationship between fatty acids and insulin sensitivity in normal humans.

Fatty acid profile of skeletal muscle phospholipids in trained and untrained young men

2000 ◽  
Vol 279 (4) ◽  
pp. E744-E751 ◽  
Author(s):  
Agneta Andersson ◽  
Anders Sjödin ◽  
Anu Hedman ◽  
Roger Olsson ◽  
Bengt Vessby
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Fatty Acid Profile ◽  
Acid Composition ◽  
Fiber Type ◽  
Young Men ◽  
Trained Group ◽  
Type Distribution ◽  
Fiber Type Distribution

Endurance trained ( n = 14) and untrained young men ( n = 15) were compared regarding the fatty acid profile of the vastus lateralis muscle after 8 wk on diets with a similar fatty acid composition. The skeletal muscle phospholipids in the trained group contained lower proportions of palmitic acid (16:0) (−12.4%, P < 0.001) and di-homo-γ-linolenic acid [20:3(n-6)] (−15.3%, P = 0.018), a lower n-6-to-n-3 ratio (−42.0%, P = 0.015), higher proportions of stearic acid (18:0) (+9.8%, P = 0.004) and sum of n-3 polyunsaturated fatty acids (+33.8%, P = 0.009), and a higher ratio between 20:4(n-6) to 20:3(n-6) (+18.4%, P = 0.006) compared with those in the untrained group. The group differences in 16:0, 20:3(n-6), 18:0/16:0, and 20:4(n-6)/20:3(n-6) were independent of fiber-type distribution. The trained group also showed a lower proportion of 16:0 (−7.9%, P < 0.001) in skeletal muscle triglycerides irrespective of fiber type. In conclusion, the fatty acid profile of the skeletal muscle differed between trained and untrained individuals, although the dietary fatty acid composition was similar. This difference was not explained by different fiber-type distribution alone but appears to be a direct consequence of changes in fatty acid metabolism due to the higher level of physical activity.

scholarly journals Nutritional ecology of essential fatty acids: an evolutionary perspective

2011 ◽  
Vol 59 (6) ◽  
pp. 369 ◽  
Author(s):  
A. J. Hulbert ◽  
Sarah K. Abbott
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Acid Composition ◽  
Membrane Lipids ◽  
Essential Fatty Acids ◽  
Dietary Fatty Acid ◽  
Omega 3 ◽  
Dietary Fatty Acid Composition

There are four types of fatty acids but only two types are essential nutritional requirements for many animals. These are the omega-6 polyunsaturated fatty acids (n-6 PUFA) and the omega-3 polyunsaturated fatty acids (n-3 PUFA) and because they cannot be converted to one another they are separate essential dietary requirements. They are only required in small amounts in the diet and their biological importance stems largely from their role as constituents of membrane lipids. They are synthesised by plants and, as a generalisation, green leaves are the source of n-3 PUFA while seeds are the source of n-6 PUFA in the food chain. While the fatty acid composition of storage fats (triglycerides) is strongly influenced by dietary fatty acid composition, this is not the case for membrane fats. The fatty acid composition of membrane lipids is relatively unresponsive to dietary fatty acid composition, although n-3 PUFA and n-6 PUFA can substitute for each in membrane lipids to some extent. Membrane fatty acid composition appears to be regulated and specific for different species. The role of essential fats in the diet of animals on (1) basal metabolic rate, (2) thermoregulation, (3) maximum longevity, and (4) exercise performance is discussed.

Essential fatty acids in fish physiology

1993 ◽  
Vol 71 (9) ◽  
pp. 684-689 ◽  
Author(s):  
B. E. March
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Essential Fatty Acids ◽  
Dietary Lipid ◽  
Significant Finding ◽  
Brood Stock ◽  
Temperature Changes ◽  
The 1960S

This paper emphasizes those aspects of fatty acid research in fish that have relevance to the investigation of the functions of essential fatty acids in other species. Lipid requirements of fish came under investigation only in the 1960s. The most significant finding has been the requirement for n − 3 fatty acids. The dietary ratio of (n − 3):(n − 6) is critical if the essential requirement is met by C18 fatty acids because of competition between fatty acids for the enzymes involved in elongation and desaturation to produce the physiologically essential long-chain fatty acids. The fatty acid composition of fish lipids varies according to the fatty acid profile of the dietary lipid. The fatty acid composition of fish also responds to temperature changes in an adaptive mechanism for maintenance of membrane homeoviscosity and physiological function over a range of temperatures. The dietary intake of essential fatty acids by brood stock must be adequate for ova formation and for embryonic development, with the latter requirement being more critical for reproductive success. Absolute requirements of fish for essential fatty acids are difficult to define and may vary depending upon the dietary ratio of (n − 3) to (n − 6) fatty acids.Key words: essential fatty acids, nutritive requirements, fish.

scholarly journals Training affects muscle phospholipid fatty acid composition in humans

2001 ◽  
Vol 90 (2) ◽  
pp. 670-677 ◽  
Author(s):  
Jørn W. Helge ◽  
Ben J. Wu ◽  
Mette Willer ◽  
Jens R. Daugaard ◽  
Leonard H. Storlien ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Exercise Training ◽  
Acid Composition ◽  
Phospholipid Fatty Acid ◽  
Muscle Membrane ◽  
Knee Extensors ◽  
Regular Exercise ◽  
Phospholipid Fatty Acid Composition

Training improves insulin sensitivity, which in turn may affect performance by modulation of fuel availability. Insulin action, in turn, has been linked to specific patterns of muscle structural lipids in skeletal muscle. This study investigated whether regular exercise training exerts an effect on the muscle membrane phospholipid fatty acid composition in humans. Seven male subjects performed endurance training of the knee extensors of one leg for 4 wk. The other leg served as a control. Before, after 4 days, and after 4 wk, muscle biopsies were obtained from the vastus lateralis. After 4 wk, the phospholipid fatty acid contents of oleic acid 18:1(n-9) and docosahexaenoic acid 22:6(n-3) were significantly higher in the trained (10.9 ± 0.5% and 3.2 ± 0.4% of total fatty acids, respectively) than the untrained leg (8.8 ± 0.5% and 2.6 ± 0.4%, P < 0.05). The ratio between n-6 and n-3 fatty acids was significantly lower in the trained (11.1 ± 0.9) than the untrained leg (13.1 ± 1.2, P < 0.05). In contrast, training did not affect muscle triacylglycerol fatty acid composition. Citrate synthase activity was increased by 17% in the trained compared with the untrained leg ( P < 0.05). In this model, diet plays a minimal role, as the influence of dietary intake is similar on both legs. Regular exercise training per se influences the phospholipid fatty acid composition of muscle membranes but has no effect on the composition of fatty acids stored in triacylglycerols within the muscle.

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