Single skeletal muscle fiber behavior after a quick stretch in young and older men: A possible explanation of the relative preservation of eccentric force in old age
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Single skeletal muscle fiber behavior after a quick stretch in young and older men : A possible explanation of the relative preservation of eccentric force in old age. / Ochala, Julien; Dorer, David J.; Frontera, Walter R.; Krivickas, Lisa S.
In: Pflugers Archiv European Journal of Physiology, Vol. 452, No. 4, 07.2006, p. 464-470.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Single skeletal muscle fiber behavior after a quick stretch in young and older men
T2 - A possible explanation of the relative preservation of eccentric force in old age
AU - Ochala, Julien
AU - Dorer, David J.
AU - Frontera, Walter R.
AU - Krivickas, Lisa S.
PY - 2006/7
Y1 - 2006/7
N2 - The origins of the smaller age-related decrease in eccentric force compared to isometric and concentric conditions in vivo remain unclear. Could this originate from contractile elements of muscle cells? The main intent of the current investigation was to assess the force behavior of muscle cells with aging, during lengthening. Chemically skinned single muscle fibers (n=235) from m. vastus lateralis of six young (mean age 31.6 years) and six older men (mean age 66.1 years) were maximally activated with pCa 4.5 at 15°C. Maximal isometric force and cross-sectional area were measured allowing the calculation of the tension (T 0). A quick stretch (2 nm per half-sarcomere length) was applied and caused an immediate increase in tension followed by a decrease and a secondary delayed and transient rise in tension (phase 3); finally, the tension recovered a steady state value (phase 4). The tension enhancements during phase 3 (ΔT 3) and phase 4 (ΔT 4) were evaluated. The myosin heavy-chain isoform composition of each single fiber was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. ΔT 3 and ΔT 4 were preserved in older men for both type I and IIa fibers despite a reduction in T 0. Therefore, the age-related preservation of the tension increments after a quick stretch in single muscle fibers could explain in part the smaller decrease in force during eccentric contractions compared to isometric and concentric conditions in vivo with aging usually observed.
AB - The origins of the smaller age-related decrease in eccentric force compared to isometric and concentric conditions in vivo remain unclear. Could this originate from contractile elements of muscle cells? The main intent of the current investigation was to assess the force behavior of muscle cells with aging, during lengthening. Chemically skinned single muscle fibers (n=235) from m. vastus lateralis of six young (mean age 31.6 years) and six older men (mean age 66.1 years) were maximally activated with pCa 4.5 at 15°C. Maximal isometric force and cross-sectional area were measured allowing the calculation of the tension (T 0). A quick stretch (2 nm per half-sarcomere length) was applied and caused an immediate increase in tension followed by a decrease and a secondary delayed and transient rise in tension (phase 3); finally, the tension recovered a steady state value (phase 4). The tension enhancements during phase 3 (ΔT 3) and phase 4 (ΔT 4) were evaluated. The myosin heavy-chain isoform composition of each single fiber was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. ΔT 3 and ΔT 4 were preserved in older men for both type I and IIa fibers despite a reduction in T 0. Therefore, the age-related preservation of the tension increments after a quick stretch in single muscle fibers could explain in part the smaller decrease in force during eccentric contractions compared to isometric and concentric conditions in vivo with aging usually observed.
KW - Aging
KW - Mechanics
KW - Skinned single muscle fiber
KW - Stretch response
UR - http://www.scopus.com/inward/record.url?scp=33745506812&partnerID=8YFLogxK
U2 - 10.1007/s00424-006-0065-6
DO - 10.1007/s00424-006-0065-6
M3 - Journal article
C2 - 16622703
AN - SCOPUS:33745506812
VL - 452
SP - 464
EP - 470
JO - Pflügers Archiv - European Journal of Physiology
JF - Pflügers Archiv - European Journal of Physiology
SN - 0031-6768
IS - 4
ER -
ID: 245665838