Subcellular localization-dependent decrements in skeletal muscle glycogen and mitochondria content following short-term disuse in young and old men
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Subcellular localization-dependent decrements in skeletal muscle glycogen and mitochondria content following short-term disuse in young and old men. / Nielsen, Joachim; Suetta, Charlotte; Hvid, Lars G.; Schrøder, Henrik D.; Aagaard, Per; Ørtenblad, Niels.
In: American Journal of Physiology - Endocrinology and Metabolism, Vol. 299, No. 6, 12.2010, p. E1053-E1060.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Subcellular localization-dependent decrements in skeletal muscle glycogen and mitochondria content following short-term disuse in young and old men
AU - Nielsen, Joachim
AU - Suetta, Charlotte
AU - Hvid, Lars G.
AU - Schrøder, Henrik D.
AU - Aagaard, Per
AU - Ørtenblad, Niels
PY - 2010/12
Y1 - 2010/12
N2 - Previous studies have shown that skeletal muscle glycogen and mitochondria are distributed in distinct subcellular localizations, but the role and regulation of these subcellular localizations are unclear. In the present study, we used transmission electron microscopy to investigate the effect of disuse and aging on human skeletal muscle glycogen and mitochondria content in subsarcolemmal (SS), intermyofibrillar (IMF), and intramyofibrillar (intra) localizations. Five young (∼23 yr) and five old (∼66 yr) recreationally active men had their quadriceps muscle immobilized for 2 wk by whole leg casting. Biopsies were obtained from m. vastus lateralis before and after the immobilization period. Immobilization induced a decrement of intra glycogen content by 54% (P < 0.001) in both age groups and in two ultrastructurally distinct fiber types, whereas the content of IMF and SS glycogen remained unchanged. A localization-dependent decrease (P = 0.03) in mitochondria content following immobilization was found in both age groups, where SS mitochondria decreased by 33% (P = 0.02), superficial IMF mitochondria decreased by 20% (P = 0.05), and central IMF mitochondria remained unchanged. In conclusion, our findings demonstrate a localization-dependent adaptation to immobilization in glycogen and mitochondria content of skeletal muscles of both young and old individuals. Specifically, this suggests that short-term disuse preferentially affects glycogen particles located inside the myofibrils and that mitochondria volume plasticity can be dependent on the distance to the fiber border.
AB - Previous studies have shown that skeletal muscle glycogen and mitochondria are distributed in distinct subcellular localizations, but the role and regulation of these subcellular localizations are unclear. In the present study, we used transmission electron microscopy to investigate the effect of disuse and aging on human skeletal muscle glycogen and mitochondria content in subsarcolemmal (SS), intermyofibrillar (IMF), and intramyofibrillar (intra) localizations. Five young (∼23 yr) and five old (∼66 yr) recreationally active men had their quadriceps muscle immobilized for 2 wk by whole leg casting. Biopsies were obtained from m. vastus lateralis before and after the immobilization period. Immobilization induced a decrement of intra glycogen content by 54% (P < 0.001) in both age groups and in two ultrastructurally distinct fiber types, whereas the content of IMF and SS glycogen remained unchanged. A localization-dependent decrease (P = 0.03) in mitochondria content following immobilization was found in both age groups, where SS mitochondria decreased by 33% (P = 0.02), superficial IMF mitochondria decreased by 20% (P = 0.05), and central IMF mitochondria remained unchanged. In conclusion, our findings demonstrate a localization-dependent adaptation to immobilization in glycogen and mitochondria content of skeletal muscles of both young and old individuals. Specifically, this suggests that short-term disuse preferentially affects glycogen particles located inside the myofibrils and that mitochondria volume plasticity can be dependent on the distance to the fiber border.
KW - Aging
KW - Cell compartmentation
KW - Immobilization
KW - Metabolism
KW - Transmission electron microscopy
UR - http://www.scopus.com/inward/record.url?scp=78649672278&partnerID=8YFLogxK
U2 - 10.1152/ajpendo.00324.2010
DO - 10.1152/ajpendo.00324.2010
M3 - Journal article
C2 - 20858747
AN - SCOPUS:78649672278
VL - 299
SP - E1053-E1060
JO - American Journal of Physiology - Endocrinology and Metabolism
JF - American Journal of Physiology - Endocrinology and Metabolism
SN - 0193-1849
IS - 6
ER -
ID: 388030733