Protein turnover in both abdominal and thigh skeletal muscle is assessed by the use of a flood-primed continuous infusion of ring-13C6- phenylalanine. This will be infused four hours before surgery, and during this period 2-3 blood samples are drawn to verify stabilization of the isotope enrichment level prior to biopsy sampling. Muscle biopsy material is divided into fractions covering myofibrillar, sarcoplasmic and connective tissue proteins and analyzed using mass spectrometry to allow for calculation of protein synthesis of both contractile muscle protein and for muscle collagen. These procedures are repeated one year post surgery.