TY  - JOUR
AU  - Andersen, J.L.
A2  - Andersen, J.L.
A2  - Gruschy-Knudsen, T.
DB  - BISp
DP  - BISp
KW  - Belastung, maximale
KW  - Leistungsphysiologie
KW  - Molekularbiologie
KW  - Muskelbiopsie
KW  - Muskelfaser
KW  - Muskelkontraktion, konzentrische
KW  - Myosin
KW  - Skelettmuskulatur
KW  - Sportmedizin
KW  - Sportwissenschaft
KW  - Untersuchung, vergleichende
LA  - eng
TI  - Rapid switch-off of the human myosin heavy chain IIX gene after heavy load muscle contractions is sustained for at least four days
TT  - Eine schnelle Abschaltung des humanen Myosin schwere Kette IIX-Gens nach starken Muskelkontraktionen wird für mindestens vier Tage aufrechterhalten
PY  - 2018
N2  - Long-term heavy load contractions decrease the relative amount of the myosin heavy chain (MHC) IIX isoform in human skeletal muscle, but the timing of the down-regulation in the short term is unknown. Untrained subjects performed two resistance bouts, in two consecutive days, with one leg, the other leg serving as a control (age 24+/-1, n=5). Muscle biopsies were obtained in both legs before, immediately after, and 24, 54, and 96 hours after exercise. Serial cryosection analysis combined immunohistochemistry and ATPase histochemistry with In Situ hybridization to identify the distribution of MHC isoforms and their corresponding transcripts, enabling identification of transitional fibers. Fibers positive solely for MHC IIX mRNA decreased in the exercised leg throughout the study period. At 96 hours post-exercise, no fibers solely expressed MHC IIX mRNA. In contrast, the number of fibers expressing MHC IIA mRNA increased throughout the study period. The percentage of fibers expressing mRNA for MHC I was unchanged in both legs at all time points. Pronounced depletion of glycogen in the MHC IIX fibers of the exercised leg verifies that the type IIX fibers were active during the heavy load contractions. Major mismatch between MHC at the mRNA and protein levels was only found in the fibers of the exercised leg. These data provide unequivocal in situ evidence of an immediate shutdown of the MHC IIX gene after resistance exercise. A further novel finding was that the silencing of the MHC IIX gene is sustained at least 4 days after removal of the stimulus.
L2  - https://dx.doi.org/10.1111/sms.12914
L2  - https://onlinelibrary.wiley.com/doi/abs/10.1111/sms.12914
DO  - 10.1111/sms.12914
SP  - S. 371-380
SN  - 0905-7188
JO  - Scandinavian journal of medicine & science in sports
IS  - 2
VL  - 28
M3  - Elektronische Ressource (online)
M3  - Gedruckte Ressource
ID  - PU201803001745
ER  -