scholarly journals Effects of a Ketogenic Diet Containing Medium-Chain Triglycerides and Endurance Training on Metabolic Enzyme Adaptations in Rat Skeletal Muscle

Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1269 ◽  
Author(s):  
Ayumi Fukazawa ◽  
Atsuko Koike ◽  
Takuya Karasawa ◽  
Momoko Tsutsui ◽  
Saki Kondo ◽  
...  

Long-term intake of a ketogenic diet enhances utilization of ketone bodies, a particularly energy-efficient substrate, during exercise. However, physiological adaptation to an extremely low-carbohydrate diet has been shown to upregulate pyruvate dehydrogenase kinase 4 (PDK4, a negative regulator of glycolytic flux) content in skeletal muscle, resulting in impaired high-intensity exercise capacity. This study aimed to examine the effects of a long-term ketogenic diet containing medium-chain triglycerides (MCTs) on endurance training-induced adaptations in ketolytic and glycolytic enzymes of rat skeletal muscle. Male Sprague-Dawley rats were placed on either a standard diet (CON), a long-chain triglyceride-containing ketogenic diet (LKD), or an MCT-containing ketogenic diet (MKD). Half the rats in each group performed a 2-h swimming exercise, 5 days a week, for 8 weeks. Endurance training significantly increased 3-oxoacid CoA transferase (OXCT, a ketolytic enzyme) protein content in epitrochlearis muscle tissue, and MKD intake additively enhanced endurance training–induced increases in OXCT protein content. LKD consumption substantially increased muscle PDK4 protein level. However, such PDK4 increases were not observed in the MKD-fed rats. In conclusion, long-term intake of ketogenic diets containing MCTs may additively enhance endurance training–induced increases in ketolytic capacity in skeletal muscle without exerting inhibitory effects on carbohydrate metabolism.

2015 ◽  
Vol 100 (4) ◽  
pp. 450-462 ◽  
Author(s):  
S. V. Ramos ◽  
P. C. Turnbull ◽  
R. E. K. MacPherson ◽  
P. J. LeBlanc ◽  
W. E. Ward ◽  
...  

2011 ◽  
Vol 111 (2) ◽  
pp. 427-434 ◽  
Author(s):  
Lorenzo K. Love ◽  
Paul J. LeBlanc ◽  
J. Greig Inglis ◽  
Nicolette S. Bradley ◽  
Jon Choptiany ◽  
...  

Pyruvate dehydrogenase (PDH) is a mitochondrial enzyme responsible for regulating the conversion of pyruvate to acetyl-CoA for use in the tricarboxylic acid cycle. PDH is regulated through phosphorylation and inactivation by PDH kinase (PDK) and dephosphorylation and activation by PDH phosphatase (PDP). The effect of endurance training on PDK in humans has been investigated; however, to date no study has examined the effect of endurance training on PDP in humans. Therefore, the purpose of this study was to examine differences in PDP activity and PDP1 protein content in human skeletal muscle across a range of muscle aerobic capacities. This association is important as higher PDP activity and protein content will allow for increased activation of PDH, and carbohydrate oxidation. The main findings of this study were that 1) PDP activity ( r2 = 0.399, P = 0.001) and PDP1 protein expression ( r2 = 0.153, P = 0.039) were positively correlated with citrate synthase (CS) activity as a marker for muscle aerobic capacity; 2) E1α ( r2 = 0.310, P = 0.002) and PDK2 protein ( r2 = 0.229, P =0.012) are positively correlated with muscle CS activity; and 3) although it is the most abundant isoform, PDP1 protein content only explained ∼18% of the variance in PDP activity ( r2 = 0.184, P = 0.033). In addition, PDP1 in combination with E1α explained ∼38% of the variance in PDP activity ( r2 = 0.383, P = 0.005), suggesting that there may be alternative regulatory mechanisms of this enzyme other than protein content. These data suggest that with higher muscle aerobic capacity (CS activity) there is a greater capacity for carbohydrate oxidation (E1α), in concert with higher potential for PDH activation (PDP activity).


1986 ◽  
Vol 91 (3) ◽  
pp. 423-434 ◽  
Author(s):  
Richard L. Lieber ◽  
Carina B. Johansson ◽  
H.L. Vahlsing ◽  
Alan R. Hargens ◽  
Earl R. Feringa

IUBMB Life ◽  
1998 ◽  
Vol 44 (6) ◽  
pp. 1211-1216 ◽  
Author(s):  
Hisao Fujii ◽  
Yoshiharu Shimomura ◽  
Taro Murakami ◽  
Naoya Nakai ◽  
Tasuku Sato ◽  
...  

2018 ◽  
Vol 120 (2) ◽  
pp. 2404-2412 ◽  
Author(s):  
Oak‐Kee Hong ◽  
Yoon‐Hee Choi ◽  
Hyuk‐Sang Kwon ◽  
Hee‐Kyoung Jeong ◽  
Jang‐Won Son ◽  
...  

Metabolism ◽  
1987 ◽  
Vol 36 (8) ◽  
pp. 807-814 ◽  
Author(s):  
Gayle Crozier ◽  
Brigitte Bois-Joyeux ◽  
Marc Chanez ◽  
Jean Girard ◽  
Jean Peret

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