NMR-spectrophotometer integrated device to monitor neuronal activity

1.本实验室采用异核多量子相干（HMQC）技术和非侵入性定位方法，将MRI中的快速扫描回波平面成像（EPI）技术应用于最新开发的高灵敏度活体1H检测~ <13>1C NMR谱.用<13>~ 1H检测~ 1C NMR方法对活体器官注射~ 1C标记葡萄糖进行无创示踪<13>。葡萄糖在0.5小时内达到最高水平，并在bolas注射后迅速下降。然而，由葡萄糖的代谢反应衍生的谷氨酰胺/谷氨酸在1小时内达到最高水平，并在该高水平下再保持约2小时。在此稳定期，应用化学位移成像技术研究这些代谢物在脑内的分布.本文介绍了一种用于活体动物血氧水平测定的可见分光光度计。为了获得血氧水平检测的灵敏度，我们采用了氧合血红蛋白和脱氧血红蛋白的Soret波段波长以及这两个波长的等吸光度点。该光度计的另一个特点是具有独立的两个探测器，可以同时测量大鼠大脑左右半球.采用近红外光谱法无创监测血液中的氧水平。为此，Chance博士的实验室开发了具有750和830 nm光源和13通道检测器的分光光度计。利用该仪器在30秒左右的时间内对大鼠脑缺血时的脱氧和血容量进行了追踪，并绘制了相应的图谱.一种部分配体的NO-血红蛋白被阐明具有独特的氧结合性质。通过光谱和氧结合研究发现它是典型的T-结构。因此，这种类型的血红蛋白可以用作活体系统中需要氧的组织或器官处的有效氧释放。

1. Fast scanning echo planar imaging (EPI) approach in MRI was incorporated into newly developed highly sensitive ^1H-detected in vivo ^<13>C NMR spectroscopy, which was developed in our laboratory by the integration of hetero nuclear multiple quantum coherence (HMQC) technique and non-invasive localization method.2. Injected glucose labeled by ^<13>C into living organs was traced non-invasively by ^1H-detected ^<13>C NMR method. Glucose reached to the highest level in 0.5 hours and decreased rapidly after a bolas injection. However, glutamine/glutamate derived by the metabolic reaction of the glucose reached to the highest level in 1 hour and stayed at this high level for approximately two more hours. In this stable period a chemical shift imaging technique was applied to investigate the distribution of these metabolites in brain.3. A visible spectrophotometer has been developed to investigate blood oxygen level in living animals. In order to gain sensitivity for blood-oxygen level detection, we employed a Soret-band wavelengths of oxy and deoxy hemoglobin and isosbestic point of these two absorbances. Another feature of the photometer is that this instrument has independent two detectors, which can simultaneously measure right and left hemisphere in rat brain.4. Near infra red spectroscopy was employed to monitor non-invasively oxygen level in blood. For this a spectrophotometer having 750 and 830nm light sources and 13-channel detector was developed in Dr. Chance's laboratory. With this instrument deoxygenation and blood volume were traced during brain ischemia in rat and their maps were also constructed in approximately 30 seconds.5. A partially liganded NO-hemoglobin was elucidated to bear unique nature in oxygen binding. It was found to be in typical T-structure by spectroscopic and oxygen binding studies. Therefore, this type of hemoglobin may be utilized as an effective oxygen release at the oxygen-demanded tissues or organs in-living system.