Sonnewald U, Wang A Y, Petersen S B, Westergaard N, Schousboe A, Erikson R, Skottner A
MR-Centre, SINTEF UNIMED, Trondheim, Norway.
Neuroreport. 1995 Apr 19;6(6):878-80. doi: 10.1097/00001756-199504190-00013.
Development of differential cell culture systems has facilitated the study of cellular and physiological actions of growth factors. Here we report the novel effects of insulin and insulin-like growth factor (IGF)-I on energy metabolism in cerebral cortical neurones, astrocytes and co-cultures thereof. Incorporation of label from [1-13C]glucose into lactate has been shown to involve both glycolysis and the tricarboxylic acid cycle in astrocytes. Thus 13C nuclear magnetic resonance spectroscopy was used to monitor mitochondrial function by measuring 13C labelling of the C-2 position of lactate. It could be demonstrated that insulin and IGF-I have similar effects on mitochondria but individual effects on cytosolic glucose metabolism. Evidence is presented that IGF-I and insulin stimulate neurones to release factors affecting astrocytic lactate production. Furthermore, lactate released from neuronal-astrocytic co-cultures was mostly of astrocytic origin, implicating the importance of lactate for neuronal metabolism.
差异细胞培养系统的发展促进了对生长因子的细胞和生理作用的研究。在此，我们报告胰岛素和胰岛素样生长因子（IGF）-I对大脑皮质神经元、星形胶质细胞及其共培养物中能量代谢的新作用。已证明将[1-¹³C]葡萄糖中的标记掺入乳酸中涉及星形胶质细胞中的糖酵解和三羧酸循环。因此，¹³C核磁共振光谱法通过测量乳酸C-2位置的¹³C标记来监测线粒体功能。可以证明，胰岛素和IGF-I对线粒体有相似的作用，但对胞质葡萄糖代谢有各自不同的作用。有证据表明，IGF-I和胰岛素刺激神经元释放影响星形胶质细胞乳酸生成的因子。此外，从神经元-星形胶质细胞共培养物中释放的乳酸大多来源于星形胶质细胞，这表明乳酸对神经元代谢的重要性。
