Ishida T, Chap Z, Chou J, Lewis R, Hartley C, Entman M, Field J B
J Clin Invest. 1983 Aug;72(2):590-601. doi: 10.1172/JCI111007.
The effect of equal (1.1 +/- 0.1 g/kg body wt) amounts of glucose administered orally, or by peripheral intravenous or intraportal infusion on hepatic glucose uptake and fractional hepatic extraction of insulin and glucagon was studied in conscious dogs with chronically implanted Doppler flow probes on the portal vein and hepatic artery and catheters in the portal vein, hepatic vein, carotid artery, and superior mesenteric vein. Portal vein and hepatic vein plasma flow increased only after oral glucose administration. Arterial plasma glucose increased equally to 150-160 mg/100 ml after all three routes of glucose administration. Portal vein glucose was similar after oral (195 +/- 15 mg/100 ml) and intraportal glucose infusion (215 +/- 11 mg/100 ml) and significantly higher than after peripheral intravenous glucose. Hepatic glucose uptake after oral (68 +/- 4%) and intraportal glucose administration (65 +/- 7%) significantly exceeded that after peripheral intravenous glucose infusion (23 +/- 5%). The amount of insulin above basal presented to the liver during the 180 min after oral glucose was 7.6 +/- 1.3 U, 4.3 +/- 0.6 U after intraportal glucose, and 4.1 +/- 0.6 U after peripheral intravenous glucose. Hepatic extraction of insulin increased significantly after oral glucose (42 +/- 3 to 61 +/- 4%), but was unchanged after intraportal and peripheral intravenous glucose administration. When the portal vein glucose levels achieved during peripheral intravenous glucose infusion for 90 min were maintained by a subsequent 90-min intraportal glucose infusion, hepatic glucose uptake was significantly greater during the intraportal glucose infusion. Glucagon secretion was suppressed equally after oral glucose, intraportal glucose, and peripheral intravenous glucose administration; fractional hepatic extraction of that hormone, which was significantly less than that of insulin, was unchanged. These results indicate that hepatic glucose uptake is significantly greater after oral and intraportal glucose administration than after peripheral intravenous glucose infusion. This difference is not simply related to the amount of glucose or insulin presented to the liver and the increased hepatic glucose uptake did not depend solely upon the augmented fractional hepatic extraction of insulin. Hepatic extraction of insulin and hepatic glucose uptake appear to be regulated independently.
在清醒犬中进行研究，这些犬经长期植入门静脉和肝动脉的多普勒血流探头以及门静脉、肝静脉、颈动脉和肠系膜上静脉的导管，观察口服等量（1.1±0.1 g/kg体重）葡萄糖、外周静脉输注葡萄糖或门静脉内输注葡萄糖对肝脏葡萄糖摄取以及胰岛素和胰高血糖素的肝脏分数提取率的影响。仅在口服葡萄糖后门静脉和肝静脉血浆流量增加。三种葡萄糖给药途径后动脉血浆葡萄糖均同等程度升高至150 - 160 mg/100 ml。口服葡萄糖（195±15 mg/100 ml）和门静脉内输注葡萄糖（215±11 mg/100 ml）后门静脉葡萄糖相似，且显著高于外周静脉输注葡萄糖后的水平。口服葡萄糖（68±4%）和门静脉内葡萄糖给药（65±7%）后肝脏葡萄糖摄取显著超过外周静脉输注葡萄糖（23±5%）。口服葡萄糖后180分钟内肝脏所接触到的高于基础水平的胰岛素量为7.6±1.3 U，门静脉内输注葡萄糖后为4.3±0.6 U，外周静脉输注葡萄糖后为4.1±0.6 U。口服葡萄糖后肝脏胰岛素提取率显著增加（从42±3%增至61±4%），但门静脉内和外周静脉输注葡萄糖给药后无变化。当通过随后90分钟的门静脉内葡萄糖输注维持外周静脉输注葡萄糖90分钟期间所达到的门静脉葡萄糖水平时，门静脉内葡萄糖输注期间肝脏葡萄糖摄取显著更高。口服葡萄糖、门静脉内输注葡萄糖和外周静脉输注葡萄糖给药后胰高血糖素分泌均同等程度受到抑制；该激素的肝脏分数提取率虽显著低于胰岛素，但未发生变化。这些结果表明，口服和门静脉内输注葡萄糖后肝脏葡萄糖摄取显著高于外周静脉输注葡萄糖。这种差异并非简单地与进入肝脏的葡萄糖或胰岛素量相关，且肝脏葡萄糖摄取增加并非仅取决于肝脏胰岛素提取率的提高。肝脏胰岛素提取率和肝脏葡萄糖摄取似乎是独立调节的。
