Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale Lausanne, Switzerland.
Centre d'Imagerie Biomédicale - Animal and Technology Core, Lausanne, Switzerland.
J Neurosci Res. 2017 Nov;95(11):2297-2306. doi: 10.1002/jnr.24032. Epub 2017 Mar 19.
Barbiturates, commonly used as general anaesthetics, depress neuronal activity and thus cerebral metabolism. Moreover, they are likely to disrupt the metabolic support of astrocytes to neurons, as well as the uptake of nutrients from circulation. By employing C magnetic resonance spectroscopy (MRS) in vivo at high magnetic field, we characterized neuronal and astrocytic pathways of energy metabolism in the rat cortex under thiopental anaesthesia. The neuronal tricarboxylic acid (TCA) cycle rate was 0.46 ± 0.02 µmol/g/min, and the rate of the glutamate-glutamine cycle was 0.09 ± 0.02 µmol/g/min. In astrocytes, the TCA cycle rate was 0.16 ± 0.02 µmol/g/min, accounting for a quarter of whole brain glucose oxidation, pyruvate carboxylase rate was 0.02 ± 0.01 µmol/g/min, and glutamine synthetase was 0.12 ± 0.01 µmol/g/min. Relative to previous experiments under light α-chloralose anaesthesia, thiopental reduced oxidative metabolism in neurons and even more so in astrocytes. Interestingly, total oxidative metabolism in the cortex under thiopental anaesthesia surpassed the rate of pyruvate production by glycolysis, indicating substantial utilisation of substrates other than glucose, likely plasma lactate. © 2017 Wiley Periodicals, Inc.
巴比妥类药物通常用作全身麻醉剂，可抑制神经元活动，从而降低大脑代谢。此外，它们可能会破坏星形胶质细胞对神经元的代谢支持，以及从循环中摄取营养物质的能力。我们采用高磁场下的¹³C 磁共振波谱（MRS）技术，对硫喷妥钠麻醉下大鼠皮质的神经元和星形胶质细胞能量代谢途径进行了研究。神经元三羧酸（TCA）循环速率为 0.46±0.02µmol/g/min，谷氨酸-谷氨酰胺循环速率为 0.09±0.02µmol/g/min。在星形胶质细胞中，TCA 循环速率为 0.16±0.02µmol/g/min，占大脑葡萄糖氧化的四分之一，丙酮酸羧化酶速率为 0.02±0.01µmol/g/min，谷氨酰胺合成酶速率为 0.12±0.01µmol/g/min。与先前在轻度α-氯醛麻醉下进行的实验相比，硫喷妥钠降低了神经元的氧化代谢，对星形胶质细胞的影响更大。有趣的是，硫喷妥钠麻醉下皮质的总氧化代谢速率超过了糖酵解产生丙酮酸的速率，表明除葡萄糖以外的其他底物（可能是血浆乳酸）被大量利用。© 2017 威立出版社
