Stable isotopes have been used safely in clinical research for decades and have contributed seminal insights into human metabolism. Magnetic Resonance Spectroscopy (MRS) Section and Core have been conducting research projects using carbon-13 (13C) labeled glucose to study brain metabolism of healthy volunteers for more than ten years.

MRS detects nuclear magnetic resonance signals from nuclei in human tissue. Common MRS detect signals from protons which are dominant nuclei in living tissues. 13C MRS detect signals from carbons instead of protons, which can provide different information of metabolism.

Because natural abundance of 13C is only one percent, signals from natural 13C is too weak to be detected. Thus, we need to administrate 13C enriched chemicals into human subjects to increase 13C signal intensity.

In an ongoing project, [U-13C6] glucose will be used. The glucose will be prepared into 20% solution for oral administration. Each human study will use 40-50 grams of [U-13C6] glucose depending on the body weight of the subject. With the administration of 13C labeled glucose, we should be able to measure 13C signals in a reasonable period of time.