Ramirez R, Sener A, Malaisse W J
Laboratory of Experimental Medicine, Erasmus Medical School, Brussels Free University, Belgium.
Mol Cell Biochem. 1995 Jan 12;142(1):43-8. doi: 10.1007/BF00928912.
The mitochondrial NADH/NAD+ ratio for free nucleotides in rat pancreatic islets was judged from the cell content in L-glutamate and L-alanine, 2-ketoglutarate and pyruvate, and NH4+. At a physiological concentration of D-glucose, such a ratio averaged 9.6 +/- 1.1%. A rise in hexose concentrations, above a threshold value in excess of 5.6 mM, caused a rapid, sustained and rapidly reversible decrease in the mitochondrial NADH/NAD+ ratio. It is speculated that in the process of glucose-stimulated insulin release, the latter change participates in the coupling between metabolic and secretory events by favouring both the activity of key mitochondrial dehydrogenases and the translocation of Ca2+ from the mitochondria into the cytosol.
大鼠胰岛中游离核苷酸的线粒体NADH/NAD⁺比值是根据L-谷氨酸、L-丙氨酸、2-酮戊二酸、丙酮酸和NH₄⁺的细胞含量来判断的。在生理浓度的D-葡萄糖条件下，该比值平均为9.6±1.1%。当己糖浓度升高超过阈值5.6 mM时，线粒体NADH/NAD⁺比值会迅速、持续且快速可逆地降低。据推测，在葡萄糖刺激胰岛素释放的过程中，后一种变化通过促进关键线粒体脱氢酶的活性以及Ca²⁺从线粒体向细胞质的转运，参与了代谢和分泌事件之间的偶联。
