A 9-wk docosahexaenoic acid-enriched supplementation improves endurance exercise capacity and skeletal muscle mitochondrial function in adult rats

Abstract

Among the causes, modifications of the mitochondrial function could be of major importance. Polyunsaturated fatty (-3) acids have been shown to play a role in intracellular functions. We hypothesize that docosahexaenoic acid (DHA) supplementation could improve muscle mitochondrial function that could contribute to limit the early consequences of aging on adult muscle. Twelve-month-old male Wistar rats were fed a low-polyunsaturated fat diet and were given DHA (DHA group) or placebo (control group) for 9 wk. Rats from the DHA group showed a higher endurance capacity (ϩ56%, P Ͻ 0.05) compared with control animals. Permeabilized myofibers from soleus muscle showed higher O2 consumptions (P Ͻ 0.05) in the DHA group compared with the control group, with glutamate-malate as substrates, both in basal conditions (i.e., state 2) and under maximal conditions (i.e., state 3, using ADP), along with a higher apparent Km for ADP (P Ͻ 0.05). Calcium retention capacity of isolated mitochondria was lower in DHA group compared with the control group (P Ͻ 0.05). Phospho-AMPK/AMPK ratio and PPAR␦ mRNA content were higher in the DHA group compared with the control group (P Ͻ 0.05). Results showed that DHA enhanced endurance capacity in adult animals, a beneficial effect potentially resulting from improvement in mitochondrial function, as suggested by our results on permeabilized fibers. DHA supplementation could be of potential interest for the muscle function in adults and for fighting the decline in exercise tolerance with age that could imply energy-sensing pathway, as suggested by changes in phospho-AMPK/AMPK ratio. polyunsaturated fatty acids; isolated mitochondria; permeabilized myofibers; muscle bioenergetics AGING IS ASSOCIATED WITH A PROGRESSIVE DECREASE in muscle mass and alterations in muscle function leading to reduced physical abilities, exercise performance and quality of life, and ultimately disabilities (21,26,36). Among the causes of such sarcopenia, inadequate protein synthesis matching protein degradations is of major importance (4, 12). Also, changes in metabolism could be part of the muscle mass decrease with age.

Fatty Acids: From Membrane Ingredients to Signaling Molecules

“…Hess et al [64] reported that dietary algae and marine fish increase the levels of EPA and DHA in the equine skeletal muscles. Guen et al [65] reported that DHA-enriched supplementation improves endurance exercise capacity and skeletal muscle mitochondrial function in murine skeletal muscle. Stebbins et al [66] reported that DHA + EPA enhances skeletal-muscle blood and vascular conductance in active skeletal muscle (especially type I and IIa fibers) and that the increase in muscle blood is due to an increase in cardiac output secondary to increases in vascular conductance [66].…”

DHA alleviates diet-induced skeletal muscle fiber remodeling via FTO/m6A/DDIT4/PGC1α signaling

“…DHA is an essential fatty acid that is ubiquitous in marine animals and plant plankton [ 9 ]. Previous studies have reported that the bioactivities of DHA, such as improvement in brain function [ 10 ], antitumor activity [ 11 ], regulation of lipid metabolism [ 12 ], regulation of glucose metabolism [ 13 ], anti-inflammatory effect [ 14 ], and improvement on exercise training and performance [ 15 ]. Increasing evidence also supports the beneficial effects of DHA on skeletal muscle function, such as alleviating muscular atrophy [ 16 ], ameliorating endurance exercise capacity [ 17 ], and contributing in recovery from exhaustion [ 18 ].…”

Effects of eicosapentaenoic acid intake on denervation-induced mitochondrial adaptation in mouse skeletal muscle

“…Interestingly, EPA supplementation improved endurance exercise capacity and skeletal muscle mitochondrial function in adult rats 23) . Although we did not measure the mitochondrial function, EPA supplementation may improve not only mitochondrial content, but also respiratory function possibly via altering protein dynamics.…”