EFFECT OF GROWTH-HORMONE ON HEPATIC GLUCOSE AND INSULIN METABOLISM AFTER ORAL GLUCOSE IN CONSCIOUS DOGS

This study examined the effect of growth hormone (GH) on hepatic gluco se metabolism and on the fractional extraction of insulin and glucagon after oral glucose administration. GH treatment [canine GH (0.75 mg/d ay for 7 days)] significantly increased basal portal vein and hepatic artery flow (P < 0.01 compared with pre-GH treatment). After GH treatm ent and after oral glucose, glucose levels significantly exceeded thos e before GH at 100 and 120 min in arterial and portal vein plasma and 120 min in the hepatic vein. The net hepatic uptake of glucose was sim ilar before and after GH treatment. The increment of net nonhepatic sp lanchnic insulin balance above basal was 131 +/- 31 mU.kg(-1).3 h(-1) before and 272 +/- 46 mU.kg(-1).3 h(-1) after GH treatment (P < 0.05). An increase in fractional hepatic extraction of insulin occurred befo re GH treatment and was significantly greater at 60 min. In summary, d espite the increased insulin content after GH administration, there wa s no change in hepatic uptake of glucose, indicating that the liver wa s also the site of insulin resistance.