GROWTH HORMONE-BINDING PROTEIN IN PARTIALLY HEPATECTOMIZED RATS

The role of the liver in regulating serum growth hormone-binding prote in (GH-BP) was studied. We measured rat serum GH-BP and insulin-like g rowth factor 1 (IGF-1) 30 min to 96 h after 70% partial hepatectomy (P HP) or sham operation in adult male rats. Serum GH-BP declined sharply from 5.8 +/- 0.1% at baseline to 3.9 +/- 0.5% by 48 h following PHP. By 72 h serum GH-BP returned to baseline level and remained at that le vel 96 h postoperatively. In sham-operated female rats, serum GH-BP wa s about 2-fold higher than in males (10.5 +/- 1.46 versus 5.8 +/- 0.2% ), whereas 24 h after hepatectomy a significant drop of about 50% was observed (p < 0.001). Serum IGF-1 decreased within 2-4 h postoperative ly in both sham-operated and PHP groups, but thereafter was lower in t he PHP rats, up to 48 h after operation, compared to sham-operated rat s (p < 0.03). The study shows that the liver has an important role in the determination of serum GH-BP levels. The return to normal GH-BP le vel, even before the liver regained its full size following hepatectom y, suggests an increase in GH-BP production by the regenerating liver.