Depression of liver protein synthesis during surgery is prevented by growth hormone

This study was undertaken to elucidate the specific effects of growth hormo ne (GH) on liver protein metabolism in humans during surgery. Otherwise hea lthy patients scheduled for elective laparoscopic cholecystectomy were rand omized into controls (n = 9) or pretreatment with 12 units of GH for I day (GH 1, n = 9) or daily for 5 days (GH 5, n = 10). The fractional synthesis rate of liver proteins, as assessed by flooding with [H-2(5)]phenylalanine, was higher in the GH 5 group (22.0 +/- 6.9%/day, mean +/- SD, P < 0.05) th an in the control (16.1 +/- 3.1%/day) and GH 1 (16.5 +/- 5.5%/day) groups. During surgery, the fraction of polyribosomes in the liver, as assessed by ribosome analysis, decreased in the control group by similar to 12% (P < 0. 01) but did not decrease in the GH-treated groups. In addition, the concent rations of the essential amino acids and aspartate in the liver decreased i n response to GH treatment. In conclusion, GH pretreatment decreases hepati c free amino acid concentrations and preserves liver protein synthesis duri ng surgery.