Brain of the conscious dog is sensitive to physiological changes in circulating insulin
Brain of the conscious dog is sensitive to physiological changes in circulating insulin
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DOI：
10.1152/ajpendo.1997.272.4.e567
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发表时间：
1997-04-01
影响因子：
5.1
通讯作者：
Cherrington, AD
中科院分区：
文献类型：
--
作者：
Davis, SN;Dunham, B;Cherrington, AD
本研究的目的是确定是否有选择性的，生理相关的增加，血液中的胰岛素灌注大脑有影响的反调节反应低血糖。实验在12只清醒的禁食18小时的狗上进行。在单独的随机研究中，将胰岛素输注（1 mU.kg（-1）.min（-1））至外周静脉（n = 6）或颈动脉和椎动脉（n = 6）。这导致等同的全身胰岛素血症（38 +/- 2 vs. 35 +/- 5 mu U/ml），但头部胰岛素水平不同（外周输注期间为38 +/- 2 mu U/ml，头部胰岛素输注期间估计为90 mu U/ml）。在外周胰岛素输注期间输注葡萄糖，以使低血糖水平（58 +/- 2 mg/dl）等同于头部胰岛素输注期间获得的低血糖水平（57 +/- 2 mg/dl）。尽管外周胰岛素水平和低血糖相当，但头部胰岛素输注期间肾上腺素、胰高血糖素和皮质醇反应曲线下面积增量增加（P < 0.05）。与外周胰岛素输注相比，头部注射时的净肝葡萄糖输出量、新生血管生成和脂肪分解增加了50-100%（P < 0.05）。我们的结论是，在清醒的狗低血糖1）生理相关的增加血液中的胰岛素的头部可以放大神经内分泌和代谢的反调节反应和2）胰高血糖素分泌可以调节，部分，神经传出活动。
The aim of this study was to determine whether a selective, physiologically relevant increase in blood-borne insulin perfusing the brain has an impact on the counterregulatory response to hypoglycemia. Experiments were carried out on 12 conscious 18-h-fasted dogs. Insulin was infused (1 mU.kg(-1).min(-1)) in separate, randomized studies into a peripheral vein (n = 6) or both carotid and vertebral arteries (n = 6). This resulted in equivalent systemic insulinemia (38 +/- 2 vs. 35 +/- 5 mu U/ml) but differing head insulin levels (38 +/- 2 mu U/ml during peripheral infusion and an estimated 90 mu U/ml during head insulin infusion). Glucose was infused during peripheral insulin infusion to equate the level of hypoglycemia (58 +/- 2 mg/dl) to that obtained during head insulin infusion (57 +/- 2 mg/dl). Despite equivalent peripheral insulin levels and hypoglycemia, incremental area under the curve responses for epinephrine, glucagon and cortisol were increased during head insulin infusion (P < 0.05). Net hepatic glucose output, gluconeogenesis, and lipolysis were increased 50-100% (P < 0.05) during head compared with peripheral insulin infusion. We conclude that during hypoglycemia in the conscious dog 1) physiologically relevant increases of blood-borne insulin to the head can amplify neuroendocrine and metabolic counterregulatory responses and 2) glucagon secretion can be regulated, in part, by neural efferent activity.