Rothman D L, Behar K L, Hetherington H P, den Hollander J A, Bendall M R, Petroff O A, Shulman R G
Proc Natl Acad Sci U S A. 1985 Mar;82(6):1633-7. doi: 10.1073/pnas.82.6.1633.
We have used (13C)-1H NMR spectroscopy at 360.13 MHz to resolve the 13C coupled proton resonance of glutamate and lactate in the rat brain in vivo. The time required for the 13C fractional enrichment of the 4-CH2 position of brain glutamate to reach isotopic steady state was determined during a continuous infusion of D-[1-13C]glucose. Under conditions of ischemia, measurements made of the 3-CH3 of lactate in (13C)-1H NMR spectra revealed the relative contribution of brain glucose and glycogen to lactate formation. (13C)-1H NMR was 11 times more sensitive than 13C NMR for the detection of 13C in the 3-CH3 position of lactate and 6 times more sensitive for the detection of 13C in the 4-CH2 of glutamate under similar in vivo conditions.
我们使用了360.13兆赫兹的(13C)-1H核磁共振光谱来解析大鼠脑内谷氨酸和乳酸的13C耦合质子共振。在持续输注D-[1-13C]葡萄糖期间,测定了脑谷氨酸4-CH2位置的13C分数富集达到同位素稳态所需的时间。在缺血条件下,(13C)-1H核磁共振光谱中对乳酸3-CH3的测量揭示了脑葡萄糖和糖原对乳酸形成的相对贡献。在类似的体内条件下,(13C)-1H核磁共振对检测乳酸3-CH3位置的13C比13C核磁共振敏感11倍,对检测谷氨酸4-CH2的13C敏感6倍。