Geriatric Psychiatry Research Program, McLean Hospital, Belmont, MA, USA.
NMR Biomed. 2010 Apr;23(3):242-50. doi: 10.1002/nbm.1444.
Evidence suggests that mitochondria undergo functional and morphological changes with age. This study aimed to investigate the relationship of brain energy metabolism to healthy aging by assessing tissue specific differences in metabolites observable by phosphorus ((31)P) MRS. (31)P MRSI at 4 Tesla (T) was performed on 34 volunteers, aged 21-84, screened to exclude serious medical and psychiatric diagnoses. Linear mixed effects models were used to analyze the effects of age on phosphorus metabolite concentrations, intracellular magnesium and pH estimates in brain tissue. A significant age associated decrease in brain pH (-0.53% per decade), increase in PCr (1.1% per decade) and decrease in PME (1.7% per decade) were found in total tissue, with PCr effects localized to the gray matter. An increase in beta NTP as a function of age (1% per decade) approached significance (p = 0.052). There were no effects demonstrated with increasing age for intracellular magnesium, PDE or inorganic phosphate. This study reports the effects of healthy aging on brain chemistry in the gray matter versus white matter using (31)P MRS measures of high energy phosphates, pH and membrane metabolism. Increased PCr, increased beta NTP (reflecting ATP) and reduced pH may reflect altered energy production with healthy aging. Unlike some previous studies of aging and brain chemistry, this study examined healthy, non-demented and psychiatrically stable older adults and specifically analyzed gray-white matter differences in brain metabolism.
有证据表明，线粒体随着年龄的增长会发生功能和形态上的变化。本研究旨在通过评估磷 ((31)P)磁共振波谱 (MRS) 观察到的组织特异性代谢物来研究脑能量代谢与健康衰老的关系。在 4 特斯拉 (T) 上对 34 名志愿者进行了 ((31)P) MRSI 检查，这些志愿者年龄在 21-84 岁之间，经过筛选排除了严重的医学和精神诊断。线性混合效应模型用于分析年龄对磷代谢物浓度、脑内镁和 pH 值的影响。在总组织中发现脑 pH 值呈显著的年龄相关下降 (-0.53%/十年)、PCr 增加 (1.1%/十年) 和 PME 减少 (1.7%/十年)，PCr 的影响局限于灰质。β-NTP 随年龄增加的增加 (1%/十年) 接近显著 (p = 0.052)。随着年龄的增长，细胞内镁、PDE 或无机磷酸盐没有表现出任何影响。本研究报告了使用 (31)P MRS 测量高能磷酸化合物、pH 值和膜代谢来评估灰质与白质的健康衰老对脑化学的影响。PCr 增加、β-NTP 增加（反映 ATP）和 pH 值降低可能反映了健康衰老时能量产生的改变。与一些以前的衰老和大脑化学研究不同，本研究检查了健康、非痴呆和精神稳定的老年人，并专门分析了大脑代谢的灰质-白质差异。
