EFFECTS OF GROWTH-HORMONE ADMINISTRATION ON SKELETAL-MUSCLE GLUTAMINE-METABOLISM IN SEVERELY TRAUMATIZED PATIENTS - PRELIMINARY-REPORT

We have investigated the effects of 24 h human recombinant growth horm one (hGH) administration on leg muscle glutamine exchange and protein kinetics in severely traumatized patients. Muscle amino acid exchange and protein balance were evaluated using the leg arteriovenous balance technique, whereas changes in skeletal muscle free amino acid concent rations were evaluated in biopsy specimens. hGH infusion decreased phe nylalanine release from protein degradation by 56 +/- 14%, and the rat e of branched chain amino acid catabolism by 51 +/- 10%. Glutamine rel ease from leg muscle was suppressed by 58 +/- 12%. This latter effect was completely accounted for by a hGH-mediated suppression of glutamin e synthesis in skeletal muscle. In conclusion, growth hormone administ ration In trauma patients may restrain protein and amino acid cataboli sm in skeletal muscle. However, the growth hormone-mediated suppressio n of glutamine production we have observed in this study could decreas e the systemic availability of this amino acid. During growth hormone treatment, this potential side-effect could be prevented by an exogeno us glutamine administration.