National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA.
NMR Biomed. 2021 Jun;34(6):e4501. doi: 10.1002/nbm.4501. Epub 2021 Mar 8.
Carbonic anhydrase (CA) plays an important role in many biological processes. Recent technological advances have demonstrated the feasibility of measuring CA activity in the occipital lobe of human subjects in vivo. In this work we report, for the first time, in vivo measurement of CA activity in the frontal lobe of human brain, where structural and function abnormalities are strongly associated with symptoms of major psychiatric disorders. Despite the much larger magnetic field distortion in the frontal lobe, the pseudo first-order bicarbonate dehydration rate constant was determined with high precision using in vivo C magnetic resonance magnetization transfer spectroscopy following oral administration of [U- C ]glucose. Nuclear Overhauser effect pulses were used to increase the signal-to-noise ratio; no proton decoupling was applied. The unidirectional dehydration rate constant of bicarbonate was found to be 0.26 ± 0.07 s , which is not statistically different from the dehydration rate constant in the occipital lobe determined in our previous study, indicating that CA activity in the two brain regions is essentially indistinguishable. These results demonstrate the feasibility of characterizing CA activity in the frontal lobe for future psychiatric studies.
碳酸酐酶（CA）在许多生物过程中发挥着重要作用。最近的技术进步已经证明了在人体枕叶中测量 CA 活性的可行性。在这项工作中，我们首次报告了在人脑额叶中 CA 活性的活体测量，其中结构和功能异常与主要精神疾病的症状强烈相关。尽管在前额叶中存在更大的磁场失真，但通过口服[U- C]葡萄糖后进行活体 13 C 磁共振磁化转移波谱学，可以高精度地确定伪一级碳酸氢盐脱水速率常数。使用核 Overhauser 效应脉冲来提高信噪比；未施加质子去耦。发现碳酸氢盐的单向脱水速率常数为 0.26±0.07 s ，与我们之前在枕叶中确定的脱水速率常数没有统计学差异，表明两个脑区的 CA 活性基本相同。这些结果表明，对于未来的精神科研究，在额叶中描述 CA 活性是可行的。
