Effects of growth hormone on protein metabolism. Acute changes in plasma amino acids in growth retarded patients with and without growth hormone deficiency.

39 patients with growth retardation were investigated: 21 (group H) were suffering from GH deficiency and 18 (group N) had no endocrine disease except for two adequately treated patients with mild hypothyroidism. Analysis of 15 plasma amino acid concentrations was carried out before and 1 and 2 hours after intravenous HGH injection at a dosage of 2 mg per m2. Except for one amino acid no significant difference between mean pre-treatment amino acid values was observed in the two groups of patients. In group H there was a highly significant decrease in plasma concentration of 14 amino acids already 1 hour after HGH injection and of all 15 amino acids after 2 hours. This response of plasma amino acids to HGH was less pronounced in group N. For 5 amino acids a moderate correlation was found in group H between acute metabolic response to HGH and growth response to long-term HGH treatment. Our results following HGH injection may reflect increased plasma amino acid transfer into cells due to HGH.