TY - JOUR

T1 - Eccentric contractions affect muscle membrane phospholipid fatty acid composition in rats

AU - Helge, Jørn Wulff

AU - Therkildsen, K J

AU - Jørgensen, T B

AU - Wu, B J

AU - Storlien, L H

AU - Asp, Stefan Erik

PY - 2001/9/1

Y1 - 2001/9/1

N2 - This study investigated if prior eccentric contractions, and thus mechanical strain and muscle damage, exert an effect on the muscle membrane phospholipid fatty acid composition in rats, and whether a possible effect could be attenuated by dietary supplements. Twenty-three rats were randomised to three groups who received chow with added fish oil (n = 8), vitamin C (n = 8) or no supplement (n = 7). After 3 weeks of feeding, calf muscles on one side were stimulated electrically during anaesthesia causing eccentric contractions. Two days later the white gastrocnemius, a part of the stimulated calf muscle, was excised from both legs. In the muscles stimulated to contract eccentrically, compared to the control muscles, the proportion of arachidonic acid, C20:4,n-6 (17.7 +/- 0.6; 16.4 +/- 0.4% of total fatty acids, respectively) and docosapentanoeic acid, C22:5,n-3 (2.9 +/- 0.1 and 2.7 +/- 0.1% of total fatty acids, respectively) was uniformly higher across groups (P <0.02) with no differences between diet groups. The proportion of long chain polyunsaturates was also significantly higher in the eccentrically contracted (39.9 +/- 0.6% of total fatty acids) compared to the control leg (38.2 +/- 0.6% of total fatty acids; P <0.01). In contrast no differences were observed in the fatty acid composition of the triacylglycerols stored within the muscle. Thus one severe bout of eccentric contractions modulates the fatty acid composition of the muscle membrane phospholipids when compared to a control leg, and supplemental intake of fish oil or vitamin C did not attenuate this effect.

AB - This study investigated if prior eccentric contractions, and thus mechanical strain and muscle damage, exert an effect on the muscle membrane phospholipid fatty acid composition in rats, and whether a possible effect could be attenuated by dietary supplements. Twenty-three rats were randomised to three groups who received chow with added fish oil (n = 8), vitamin C (n = 8) or no supplement (n = 7). After 3 weeks of feeding, calf muscles on one side were stimulated electrically during anaesthesia causing eccentric contractions. Two days later the white gastrocnemius, a part of the stimulated calf muscle, was excised from both legs. In the muscles stimulated to contract eccentrically, compared to the control muscles, the proportion of arachidonic acid, C20:4,n-6 (17.7 +/- 0.6; 16.4 +/- 0.4% of total fatty acids, respectively) and docosapentanoeic acid, C22:5,n-3 (2.9 +/- 0.1 and 2.7 +/- 0.1% of total fatty acids, respectively) was uniformly higher across groups (P <0.02) with no differences between diet groups. The proportion of long chain polyunsaturates was also significantly higher in the eccentrically contracted (39.9 +/- 0.6% of total fatty acids) compared to the control leg (38.2 +/- 0.6% of total fatty acids; P <0.01). In contrast no differences were observed in the fatty acid composition of the triacylglycerols stored within the muscle. Thus one severe bout of eccentric contractions modulates the fatty acid composition of the muscle membrane phospholipids when compared to a control leg, and supplemental intake of fish oil or vitamin C did not attenuate this effect.

KW - Animals

KW - Antioxidants

KW - Ascorbic Acid

KW - Blood Glucose

KW - Dietary Fats

KW - Electric Stimulation

KW - Fatty Acids

KW - Fish Oils

KW - Lactic Acid

KW - Male

KW - Muscle Contraction

KW - Muscle, Skeletal

KW - Phospholipids

KW - Random Allocation

KW - Rats

KW - Rats, Wistar

KW - Stress, Mechanical

KW - Triglycerides

M3 - Journal article

C2 - 11571487

VL - 86

SP - 599

EP - 604

JO - Experimental Physiology

JF - Experimental Physiology

SN - 0958-0670

IS - 5

ER -