Kusaka M, Ui M
Am J Physiol. 1977 Feb;232(2):E145-55. doi: 10.1152/ajpendo.1977.232.2.E145.
The effect of epinephrine on Cori cycle activity has been studied by a tracer kinetic technique. The subcutaneous injection of epinephrine into fasted adrenodemedullated rats activated gluconeogenesis and increased glucose utilization. Most of the glucose utilized in epinephrine-treated rats was converted to lactate, and the conversion to the metabolites other than lactate was markedly suppressed by epinephrine. As a result, not only hyperglycemia and hyperlactacidemia developed, but also the contribution of the Cori cycle to glucose metabolism increased after epinephrine. The glucose-alanine cycle, which is roughly one-third as active as the Cori cycle, was only slightly activated by epinephrine. No evidence was obtained, in vivo and in vitro, for the increased formation of lactate from muscle glycogen which decomposed in response to epinephrine. It is suggested that, in epinephrine-treated rats, blood glucose was converted to blood lactate predominantly while muscle glycogen selectively yielded the metabolites other than blood lactate. This suggests compartmentalization of glycolytic pathway in the peripheral tissues of epinephrine-treated rats.
已通过示踪动力学技术研究了肾上腺素对科里循环活性的影响。向禁食的肾上腺髓质切除大鼠皮下注射肾上腺素可激活糖异生并增加葡萄糖利用。肾上腺素处理的大鼠中利用的大部分葡萄糖转化为乳酸，而肾上腺素可显著抑制葡萄糖向乳酸以外的代谢产物的转化。结果，不仅出现了高血糖和高乳酸血症，而且肾上腺素处理后科里循环对葡萄糖代谢的贡献也增加了。葡萄糖 - 丙氨酸循环的活性约为科里循环的三分之一，仅被肾上腺素轻微激活。在体内和体外均未获得证据表明，因肾上腺素而分解的肌肉糖原会增加乳酸的生成。有人提出，在肾上腺素处理的大鼠中，血糖主要转化为血乳酸，而肌肉糖原则选择性地产生血乳酸以外的代谢产物。这表明肾上腺素处理的大鼠外周组织中糖酵解途径存在区室化。
