Endurance exercise training in myostatin null mice.
The growth factor myostatin (Mstn) is a negative regulator of skeletal muscle mass. Mstn(-/-) muscles are hypertrophied, stronger, and more glycolytic than Mstn(+/+) muscles, suggesting that they might not perform endurance exercise as well as Mstn(+/+) mice. Indeed, it has previously been shown that treadmill exercise training reduces triceps weight in Mstn(-/-) mice. To analyze the response of Mstn(-/-) muscle to endurance exercise in detail, we carried out endurance training over 4 weeks to examine muscle mass, histology, and oxidative enzyme activity. We found that muscle mass was reduced with training in several muscles from both genotypes, with no evidence of muscle damage. Citrate synthase activity was increased with training in control and mutant mice. Non-trained Mstn(-/-) mice did, however, have lower maximal exercise capacity compared with Mstn(+/+) mice. These results show that Mstn(-/-) muscle retains the metabolic plasticity necessary to adapt normally to endurance training.
Savage
Kathleen J
KJ
Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
McPherron
Alexandra C
AC
D000818:Animals; D001835:Body Weight / Q000235:genetics / Q000502:physiology; D002950:Citrate (si)-Synthase / Q000378:metabolism; D004396:Coloring Agents; D005070:Evans Blue; D006019:Glycolysis; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000201:enzymology / Q000502:physiology; D055435:Myostatin / Q000235:genetics* / Q000502:physiology*; D009929:Organ Size / Q000235:genetics / Q000502:physiology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D010807:Physical Endurance / Q000235:genetics* / Q000502:physiology*; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000378:metabolism; D013385:Succinate Dehydrogenase / Q000378:metabolism
C506944:Atp2a1 protein, mouse; D004396:Coloring Agents; D009124:Muscle Proteins; D055435:Myostatin; D005070:Evans Blue; D013385:Succinate Dehydrogenase; D002950:Citrate (si)-Synthase; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases