Effects on skeletal muscle amino acids and whole bodynitrogen metabolism of total parenteral nutrition following laparoscopic cholecystectomy and given to healthy volunteers

In this descriptive study total parenteral nutrition (TPN) without glutamine was administered over 2 days to patients undergoing laparoscopic cholecystectomy (n = 8) and to volunteers (n = 8). Effects on muscle amino acids and nitrogen economy were studied. Muscle protein synthesis, determined by ribosome and polyribosome concentrations were measured in the patients. In both patients and volunteers the muscle amino acid patterns indicated muscle protein catabolism. Decreases in glutamine were seen in both groups (21.8 ± 4.6% in patients and 17.5 ± 5.4% in the volunteers). In both groups a negative nitrogen balance was seen (−4.1 ± 1.2 gram and −10.3 ± 2.4 gram respectively). The patients also showed decreased ribosome (by 13.7 ± 4.5%) and polyribosome concentration (by 17.4 ± 4.6%), indicating a decrease in muscle protein synthesis. No comparisons are made between the two groups since they are not comparable. However, it is concluded in these two descriptive studies, that during these conditions, TPN does not prevent muscle protein catabolism either during basal conditions or after a minor surgical trauma such as laparoscopic cholecystectomy.