Growth hormone together with glutamine-containing total parenteral nutrition maintains muscle glutamine levels and results in a less negative nitrogen balance after surgical trauma.

Abstract

Muscle protein catabolism, reflected by a decrease in glutamine (GLN), a decrease in muscle protein synthesis, and a negative nitrogen balance can be reduced by either administration of GLN or growth hormone (GH). In this study, the effects of a combination of GH and GLH were studied. Patients (n = 16) undergoing abdominal operation were given total parenteral nutrition (TPN) containing either GLN alone or GLN together with GH (GH/GLN) during 3 postoperative days. The amino acid concentration and protein synthesis in muscle tissue and the nitrogen balance were measured. GH/GLN reduced nitrogen losses compared with GLN alone (-5.8 +/- 1.4 g nitrogen versus -10.6 +/- 1.1 g nitrogen, P <.05). GH/GLN maintained muscle GLN at preoperative levels compared with a 47.5% +/- 6.3% decline in the GLN group. A similar decrease was seen in the fractional synthesis rate of muscle protein postoperatively in both groups. GH has an additive effect given together with GLN on muscle amino acid metabolism, preventing the decrease in the GLN concentration in skeletal muscle and diminishing the loss of whole body nitrogen. However, the improvements in muscle amino acid concentrations and nitrogen loss were not associated with differences between the groups in muscle protein synthesis postoperatively.