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Effects of total knee arthroplasty on markers of muscle damage two hours after surgery (1102.33)
Author(s) -
Hocker Austin,
Jewett Brian,
Shah Steven,
Lantz Brick,
Dreyer Hans
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.1102.33
Subject(s) - medicine , ischemia , skeletal muscle , tourniquet , total knee arthroplasty , urology , surgery , anesthesia
Total knee arthroplasty (TKA) results in rapid muscle atrophy, decreased strength, and functional mobility limitations. Our prior reports on the acute effects of ischemia and reperfusion during TKA suggests decreased protein synthesis, increased protein degradation, and activation of the endoplasmic reticulum (ER) stress response in skeletal muscle. The purpose of this experiment was to determine if protein and transcript markers of protein synthesis, degradation, and ER stress remained elevated two hours after TKA. We studied 60‐80 year old patients before and two hours after primary TKA. Muscle biopsies were obtained in the operating room immediately before tourniquet application, at maximal ischemia, and two hours after reperfusion. Our preliminary data show the fraction of spliced XBP1 transcript increased 124% during ischemia (p = .11) and 104% after reperfusion (p < .05) relative to baseline. Protein levels of phosphorylated 4EBP1 (Thr37/46) decreased 34% during ischemia (p < .05) and 20% after reperfusion (not significant) relative to baseline. Phosphorylation of AKT (Ser473) decreased 69% during ischemia (p = .10) and nearly returned to baseline after reperfusion. Interestingly, transcript levels of ATF4 and BIP were decreased during both ischemia and recovery (p < .05) and ERDJ4 and CHOP expression was not significantly different relative to baseline during ischemia or after reperfusion. Two hours after TKA muscle cell cross sectional area was increased 34% relative to baseline. These preliminary results suggest that ischemia and reperfusion during TKA induce changes in muscle metabolism that persist two hours after surgery. Grant Funding Source : Supported by K01HD057332