Tildon J T, Roeder L M, Stevenson J H
J Neurosci Res. 1985;14(2):207-15. doi: 10.1002/jnr.490140206.
The rates of [6-14C]-glucose oxidation by reconstituted systems of cytosol and mitochondria or cytosol and synaptosomes were essentially the same as the rate of oxidation of [3-14C]-3-hydroxybutyrate. However, the rate of [U-14C]-glutamine oxidation by mitochondria was 2.5 times that by synaptosomes. The addition of glutamine (5 mM) caused a reduction in the rates of oxidation [6-14C]-glucose of 20% and 40% by mitochondria and synaptosomes, respectively. Conversely, the addition of glucose (5 mM) had little or no effect on the rate of [U-14C]-glutamine oxidation by either organelle. Amino-oxyacetate decreased [U-14C]-glutamine oxidation by mitochondria more than 35% but had little or no effect on the rate of glutamine oxidation by synaptosomes. When glucose (5 mM) was added to [3-14C]-3-hydroxybutyrate, the rates of oxidation by the mitochondria and synaptosomes were increased by 65% and 77%, respectively. However, in the reverse situation the addition of 3-hydroxybutyrate decreased [6-14C]-glucose oxidation by synaptosomes (35%) but did not decrease the rate by mitochondria. These results suggest that differences in the rates of substrate utilization by mitochondria and synaptosomes and differences in substrate interactions in these two subcellular organelles may contribute to metabolic compartmentation in the brain.
由胞质溶胶与线粒体或胞质溶胶与突触体组成的重组系统对[6-¹⁴C]-葡萄糖的氧化速率与[3-¹⁴C]-3-羟基丁酸酯的氧化速率基本相同。然而，线粒体对[U-¹⁴C]-谷氨酰胺的氧化速率是突触体的2.5倍。添加谷氨酰胺（5 mM）分别使线粒体和突触体对[6-¹⁴C]-葡萄糖的氧化速率降低了20%和40%。相反，添加葡萄糖（5 mM）对这两种细胞器对[U-¹⁴C]-谷氨酰胺的氧化速率几乎没有影响。氨基氧乙酸使线粒体对[U-¹⁴C]-谷氨酰胺的氧化速率降低超过35%，但对突触体对谷氨酰胺的氧化速率几乎没有影响。当向[3-¹⁴C]-3-羟基丁酸酯中添加葡萄糖（5 mM）时，线粒体和突触体的氧化速率分别提高了65%和77%。然而，在相反的情况下，添加3-羟基丁酸酯会使突触体对[6-¹⁴C]-葡萄糖的氧化速率降低（35%），但不会降低线粒体的氧化速率。这些结果表明，线粒体和突触体在底物利用速率上的差异以及这两种亚细胞器中底物相互作用的差异可能有助于大脑中的代谢区室化。
