Diabetes Division, 1st Propedeutic Department of Internal Medicine, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Diabetes Res Clin Pract. 2011 Aug;93 Suppl 1:S86-91. doi: 10.1016/S0168-8227(11)70019-5.
The main role of insulin in the heart under physiological conditions is obviously the regulation of substrate utilization. Indeed, insulin promotes glucose uptake and its utilization via glycolysis. Insulin, promoting glucose as the main cardiac energy substrate, reduces myocardial O(2) consumption and increases cardiac efficiency. Moreover, insulin seems to augment cardiomyocyte contraction, while it affects favorably myocardial relaxation, increases ribosomal biogenesis and protein synthesis, stimulates vascular endothelial growth factor (VEGF) and thereby angiogenesis, suppresses apoptosis, promotes cell survival and finally ameliorates both myocardial microcirculation and coronary artery resistance, leading to increased blood perfusion of myocardium. Thus, insulin acts directly on heart muscle, and this action is mediated principally through PKB/Akt signal pathway. Under pathological conditions, such as type 2 diabetes, myocardial ischaemia, and cardiac hypertrophy, insulin signal transduction pathways and action are clearly modified. In this review we summarize the evidence that the heart is an important target of insulin action and that elimination of these actions is important in disease states.
胰岛素在生理条件下于心脏中主要发挥调节底物利用的作用。确切来说，胰岛素可促进葡萄糖摄取及其经糖酵解途径的利用。胰岛素促进葡萄糖成为心脏的主要能量底物，可降低心肌耗氧量并提高心脏效率。此外，胰岛素似乎可增强心肌细胞收缩，同时有利于心肌舒张，增加核糖体生物发生和蛋白质合成，刺激血管内皮生长因子(VEGF)生成从而促进血管生成，抑制细胞凋亡，促进细胞存活，最终改善心肌微循环和冠状动脉阻力，导致心肌灌注增加。因此，胰岛素可直接作用于心肌，该作用主要通过蛋白激酶 B/蛋白激酶 Akt（PKB/Akt）信号通路介导。在 2 型糖尿病、心肌缺血和心肌肥厚等病理条件下，胰岛素信号转导通路和作用明显改变。本综述总结了胰岛素对心脏具有重要作用的证据，且消除这些作用在疾病状态下很重要。
