| Autor: |
Tjäder I; Department of Perioperative Medicine and Intensive Care, Karolinska University Hospital, 14186 Huddinge, Sweden., Klaude M; Department of Perioperative Medicine and Intensive Care, Karolinska University Hospital, 14186 Huddinge, Sweden., Hssain AA; Department of Intensive Care Unit, University Hospital of Clermont-Ferrand, 63100 Clermont-Ferrand, France., Guillet C; Unité de Nutrition Humaine, Clermont Université, Université d'Auvergne, INRA, 63001 Clermont-Ferrand, France., Nennesmo I; Department of Pathology, Karolinska Institutet, 17177 Stockholm, Sweden., Wernerman J; Department of Perioperative Medicine and Intensive Care, Karolinska University Hospital, 14186 Huddinge, Sweden., Rooyackers O; Division of Anesthesiology and Intensive Care, CLINTEC, Karolinska Institutet, 14152 Huddinge, Sweden. |
| Abstrakt: |
(1) Background: Muscle protein synthesis in critically ill patients is, on average, normal despite dramatic muscle loss, but the variation is much larger than in controls. Here, we evaluate if this variation is due to 1) heterogeneity in synthesis rates, 2) morphological variation or infiltrating cells, or 3) heterogeneity in the synthesis of different protein fractions. (2) Methods: Muscle biopsies were taken from both legs of critically ill patients ( n = 17). Mixed and mitochondrial protein synthesis rates and morphologies were evaluated in both legs. Synthesis rates of myosin and actin were determined in combined biopsies and compared with controls. (3) Results: Muscle protein synthesis rates had a large variability in the patients (1.4-10.8%/day). No differences in mixed and mitochondrial protein synthesis rates between both legs were observed. A microscopic examination revealed no morphological differences between the two legs or any infiltrating inflammatory cells. The synthesis rates for myosin were lower and for actin they were higher in the muscles of critically ill patients, compared with the controls. (4) Conclusions: The large variation in muscle protein synthesis rates in critically ill patients is not the result of heterogeneity in synthesis rates, nor due to infiltrating cells. There are differences in the synthesis rates of different proteins, but these do not explain the larger variations. |
