Brockman R P, Bergman E N
Am J Physiol. 1975 Nov;229(5):1338-43. doi: 10.1152/ajplegacy.1975.229.5.1338.
The secretion of insulin into the portal blood and its removal by the liver and kidneys in conscious fed sheep were determined by simultaneously measuring venoarterial plasma concentration differences and portal, hepatic, and renal plasma flows. The basal secretory rate of insulin was 0.43 +/- 0.03 U/h or 7.8 mU/kg-h. The secretory rate of insulin and the amount of insulin presented to the liver also were altered by 2-h intraportal infusions of glucagon (150 mug/h), insulin (1.17 U/h), and insulin (1.17 U/h) lus glucose (2.2 g/h). Hepatic removal under all conditions was about 50% of the insulin secretory rate, although the extraction ratio was only 0.08. Renal removal was 35% of the insulin secretory rate. The renal extraction ratio was 0.35. During insulin-induced hypoglycemia and also during starvation, the hepatic extraction ratio of insulin increased significantly, but the removal as a percentage of insulin secretion did not change. It appears that in sheep on a maintenance diet the basal secretory rate of insulin is less than that of nonruminant species and that, within physiological limits, the liver disposes of about one-half and the kidney about one-third of the insulin. Other tissues, presumably, remove the remaining 10--20%.
通过同时测量门脉 - 动脉血浆浓度差以及门静脉、肝和肾血浆流量，测定了清醒进食绵羊门静脉血中胰岛素的分泌以及肝脏和肾脏对胰岛素的清除情况。胰岛素的基础分泌速率为0.43±0.03U/h或7.8mU/kg - h。通过门静脉内输注2小时的胰高血糖素（150μg/h）、胰岛素（1.17U/h）以及胰岛素（1.17U/h）加葡萄糖（2.2g/h），胰岛素的分泌速率以及输送到肝脏的胰岛素量也发生了改变。在所有条件下，肝脏清除量约为胰岛素分泌速率的50%，尽管提取率仅为0.08。肾脏清除量为胰岛素分泌速率的35%。肾脏提取率为0.35。在胰岛素诱导的低血糖期间以及饥饿期间，胰岛素的肝脏提取率显著增加，但作为胰岛素分泌百分比的清除量并未改变。看来，维持饮食的绵羊胰岛素基础分泌速率低于非反刍动物，并且在生理限度内，肝脏处理约一半的胰岛素，肾脏处理约三分之一的胰岛素。据推测，其他组织清除其余的10 - 20%。
