DEVELOPMENT OF LOW FREQUENCY MULTIQUANTUM EPR FOR IN VIVO APPLICATIONS

哺乳动物的大脑是一个高度氧化的器官， 持续供应氧气。 我们正在调查 大脑中的氧分压和组织能量学之间的关系。 皮质 在麻醉大鼠中测量氧张力， 使用EPR血氧测定法的缺氧方案。 在平行实验中，我们 用磷核磁共振测量大脑能量 与后者 利用该技术，我们可以定量ATP、PCR、PI和细胞内pH。 游离ADP浓度也可以定量。 氧分压在 大脑无法维持“静止”代谢稳态的原因是 由引起高能量扰动的物质决定 公认的是，结果将是非常 对实验条件敏感。 长期目标是利用 研究代谢保护剂并确定是否 这些“保护剂”将降低临界pO2（从而增加 大脑对缺氧的耐受性）。

The mammalian brain is a highly oxidative organ and requires a constant supply of oxygen. We are investigating the relationships between oxygen tension and tissue energetics in brain. Cortical oxygen tensions are measured in anesthetized rats during a graded hypoxia protocol using EPR oximetry. In parallel experiments, we measure brain energetics using phosphorus NMR. With the latter technique, we can quantify ATP, PCR, PI and intracellular pH. The free ADP concentration can also be quantified. The oxygen tension at which the brain cannot maintain "resting" metabolic homeostasis is determined by that which causes a purturbation in either high energy phosphates or pH. It is recognized that the results will be very sensitive to experimental conditions. The long term goal is to use the protocol to investigate metabolic protectents and to determine if these "protectants" will reduce the critical pO2 (thereby increasing the brain's tolerance of hypoxia).