Nakada T, Kwee I L, Suzuki N, Houkin K
Neurochemistry Research Laboratory, Veterans Administration Medical Center, Martinez, California 94553.
Magn Reson Med. 1989 Nov;12(2):172-80. doi: 10.1002/mrm.1910120204.
Fetal brain metabolism was investigated in utero noninvasively using multinuclear nuclear magnetic resonance spectroscopy in rats at two representative prenatal stages: early (17-18 days) and late (20-21 days) stages. Phosphorus-31 (31P) spectroscopy revealed that phosphocreatine is significantly lower in the early stage and increases to the level of early neonates by the late prenatal stage. Intracellular pH at the early stage was found to be strikingly high (7.52 +/- 0.21) and decreased to a level similar to that of neonates by the late stage (7.29 +/- 0.07). Phosphomonoester levels at both stages were similar to the values reported for early neonates. Water-suppressed proton (1H) spectroscopy demonstrated a distinctive in vivo fetal brain spectral pattern characterized by low levels of N-acetyl aspartate and high levels of taurine. High-resolution proton spectroscopy and homonuclear chemical-shift correlate spectroscopy of brain perchloric acid extracts confirmed these in vivo findings. In vitro 31P spectroscopy of acidified chloroform methanol extracts showed the characteristic membrane phospholipid profiles of fetal brain. The phosphatidylethanolamine (PE)-to-phosphatidylcholine (PC) ratio (PE/PC) did not show significant changes between the two stages at 0.40 +/- 0.11, a value similar to that of early neonates.
在大鼠两个具有代表性的产前阶段，即早期（17 - 18天）和晚期（20 - 21天），使用多核磁共振波谱技术对子宫内胎儿大脑代谢进行了无创研究。磷-31（31P）波谱显示，磷酸肌酸在早期显著降低，到产前晚期增加到早期新生儿的水平。发现早期细胞内pH值极高（7.52±0.21），到晚期降至与新生儿相似的水平（7.29±0.07）。两个阶段的磷酸单酯水平与早期新生儿报道的值相似。水抑制质子（1H）波谱显示出一种独特的体内胎儿大脑光谱模式，其特征是N - 乙酰天门冬氨酸水平低，牛磺酸水平高。高分辨率质子波谱和脑高氯酸提取物的同核化学位移相关波谱证实了这些体内研究结果。酸化氯仿甲醇提取物的体外31P波谱显示了胎儿大脑特征性的膜磷脂谱。磷脂酰乙醇胺（PE）与磷脂酰胆碱（PC）的比率（PE/PC）在两个阶段之间没有显著变化，为0.40±0.11，与早期新生儿的值相似。
