Short-term immobilization and recovery affect skeletal muscle but not collagen tissue turnover in humans
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Short-term immobilization and recovery affect skeletal muscle but not collagen tissue turnover in humans. / Christensen, Britt; Dyrberg, Eva; Aagaard, Per; Kjær, Michael; Langberg, Henning.
In: Journal of Applied Physiology, Vol. 105, No. 6, 2008, p. 1845-1851.Research output: Contribution to journal › Journal article › peer-review
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TY - JOUR
T1 - Short-term immobilization and recovery affect skeletal muscle but not collagen tissue turnover in humans
AU - Christensen, Britt
AU - Dyrberg, Eva
AU - Aagaard, Per
AU - Kjær, Michael
AU - Langberg, Henning
PY - 2008
Y1 - 2008
N2 - Not much is known about the effects of immobilization and subsequent recovery on tendon connective tissue. In the present study, healthy young men had their nondominant leg immobilized for a 2-wk period, followed by a recovery period of the same length. Immobilization resulted in a mean decrease of 6% (5,413 to 5,077 mm(2)) in cross-sectional area (CSA) of the triceps surae muscles and a mean decrease of 9% (261 to 238 N.m) in strength of the immobilized calf muscles. Two weeks of recovery resulted in a 6% increased in CSA (to 5,367 mm(2)), whereas strength remained suppressed (240 N.m). No difference in Achilles tendon CSA was detected between the two legs at any time point. Local tendon collagen synthesis, measured as the peritendinous concentrations of PINP (NH(2)-terminal propeptide of type I collagen; indirect marker for collagen synthesis), was unchanged after 2 wk of immobilization. However, peritendinous levels of PINP were significantly elevated in the immobilized leg (15 to 139 ng/ml) following 2 wk of remobilization compared with preimmobilization levels. In contradiction hereto, systemic concentrations of PINP remained unchanged throughout the study. Immobilization reduced muscle size and strength, while tendon size and collagen turnover were unchanged. While recovery resulted in an increase in muscle size, strength was unchanged. No significant difference in tendon size could be detected between the two legs after 2 wk of recovery, although collagen synthesis was increased in the previously immobilized leg. Thus 2 wk of immobilization are sufficient to induce significant changes in muscle tissue, whereas tendon tissue seems to be more resistant to short-term immobilization.
AB - Not much is known about the effects of immobilization and subsequent recovery on tendon connective tissue. In the present study, healthy young men had their nondominant leg immobilized for a 2-wk period, followed by a recovery period of the same length. Immobilization resulted in a mean decrease of 6% (5,413 to 5,077 mm(2)) in cross-sectional area (CSA) of the triceps surae muscles and a mean decrease of 9% (261 to 238 N.m) in strength of the immobilized calf muscles. Two weeks of recovery resulted in a 6% increased in CSA (to 5,367 mm(2)), whereas strength remained suppressed (240 N.m). No difference in Achilles tendon CSA was detected between the two legs at any time point. Local tendon collagen synthesis, measured as the peritendinous concentrations of PINP (NH(2)-terminal propeptide of type I collagen; indirect marker for collagen synthesis), was unchanged after 2 wk of immobilization. However, peritendinous levels of PINP were significantly elevated in the immobilized leg (15 to 139 ng/ml) following 2 wk of remobilization compared with preimmobilization levels. In contradiction hereto, systemic concentrations of PINP remained unchanged throughout the study. Immobilization reduced muscle size and strength, while tendon size and collagen turnover were unchanged. While recovery resulted in an increase in muscle size, strength was unchanged. No significant difference in tendon size could be detected between the two legs after 2 wk of recovery, although collagen synthesis was increased in the previously immobilized leg. Thus 2 wk of immobilization are sufficient to induce significant changes in muscle tissue, whereas tendon tissue seems to be more resistant to short-term immobilization.
KW - Adult
KW - Casts, Surgical
KW - Collagen
KW - Collagen Type I
KW - Creatinine
KW - Enzyme-Linked Immunosorbent Assay
KW - Humans
KW - Immobilization
KW - Male
KW - Microdialysis
KW - Muscle Strength
KW - Muscle, Skeletal
KW - Tendons
KW - Young Adult
U2 - 10.1152/japplphysiol.90445.2008
DO - 10.1152/japplphysiol.90445.2008
M3 - Journal article
C2 - 18927270
VL - 105
SP - 1845
EP - 1851
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 6
ER -
ID: 10454670