Acyl-coenzyme A binding protein expression is fibre-type specific in rat skeletal muscle but not affected by moderate endurance training.
The metabolic active form of free fatty acids, long-chain acyl-coenzyme A (lc-acyl-CoA), binds to its 10-kDa binding protein with high affinity. In the present study, we investigated the content of lc-acyl-CoA binding protein (ACBP) in different skeletal muscle fibre types. Soleus had the highest expression of ACBP (0.33+/-0.02 microg mg protein(-1)) and the content was as high as in heart muscle. The content in mixed gastrocnemius (0.27+/-0.02 microg mg protein(-1)), extensor digitorum longus (0.21+/-0.01 microg mg protein(-1)) and white gastrocnemius (0.16+/-0.01 microg mg protein(-1)) were lower than in soleus and differed from each other ( P<0.05). The ACBP content correlated positively with the fraction of myosin heavy chain I in the skeletal muscles (Spearman rank correlation rho=0.90; P<0.0001), and negatively with the myosin heavy chain IIB fraction ( rho=-0.92; P<0.0001). The content of ACBP also correlated with 3-hydroxy-acyl-CoA dehydrogenase (HAD) and citrate synthase (CS). Five weeks of endurance training increased HAD and CS activities in soleus and mixed gastrocnemius but did not affect the ACBP content. These findings demonstrate that ACBP expression is fibre-type specific in skeletal muscles and correlates with beta-oxidative potential. Training-induced increase in oxidative capacity was not paralleled by an increase in ACBP content.
Franch
Jesper
J
Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Main Campus Odense University, Campusvej 55, 5230 Odense M, Denmark. franch@sportmed.sdu.dk
Andersen
Jesper L
JL
Jensen
Jørgen
J
Pedersen
Preben K
PK
Knudsen
Jens
J
D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000378:metabolism; D000214:Acyl Coenzyme A / Q000378:metabolism*; D000818:Animals; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D002950:Citrate (si)-Synthase / Q000378:metabolism; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D008297:Male; D018656:Muscle Fibers, Fast-Twitch / Q000201:enzymology; D018657:Muscle Fibers, Slow-Twitch / Q000201:enzymology; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000378:metabolism; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D010805:Physical Conditioning, Animal; D010807:Physical Endurance / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000214:Acyl Coenzyme A; D002352:Carrier Proteins; C490174:Fabp7 protein, rat; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D015094:3-Hydroxyacyl CoA Dehydrogenases; D002334:Carnitine O-Palmitoyltransferase; D002950:Citrate (si)-Synthase; D018995:Myosin Heavy Chains