Zweier J L, Thompson-Gorman S, Kuppusamy P
Department of Medicine, Johns Hopkins Medical Institutions, Francis Scott Key Medical Center, Baltimore, Maryland 21224.
J Bioenerg Biomembr. 1991 Dec;23(6):855-71. doi: 10.1007/BF00786005.
Electron paramagnetic resonance (EPR) spectroscopy can be applied to measure oxygen concentrations in cells and tissues. Oxygen is paramagnetic, and thus it interacts with a free radical label resulting in a broadening of the observed linewidth. Recently we have developed instrumentation in order to enable the performance of EPR spectroscopy and EPR oximetry in the intact beating heart. This spectrometer consists of 1-2-GHz microwave bridge with the source locked to the resonant frequency of a specially designed lumped circuit resonator. This technique is applied to measure the kinetics of the uptake and clearance of different free radical labels. It is demonstrated that this technique can be used to noninvasively measure tissue oxygen concentration. In addition, rapid scan EPR measurements can be performed enabling gated millisecond measurements of oxygen concentrations to be performed over the cardiac cycle. Thus, low-frequency EPR spectroscopy offers great promise in the study of tissue oxygen concentrations and the role of oxygen in metabolic control.
电子顺磁共振（EPR）光谱可用于测量细胞和组织中的氧浓度。氧是顺磁性的，因此它与自由基标记相互作用，导致观察到的线宽变宽。最近，我们开发了一种仪器，以便能够在完整的跳动心脏中进行EPR光谱和EPR血氧测定。该光谱仪由一个1-2 GHz的微波桥组成，其源被锁定到一个特别设计的集总电路谐振器的谐振频率。该技术用于测量不同自由基标记的摄取和清除动力学。结果表明，该技术可用于无创测量组织氧浓度。此外，还可以进行快速扫描EPR测量，从而在心动周期内对氧浓度进行门控毫秒级测量。因此，低频EPR光谱在研究组织氧浓度以及氧在代谢控制中的作用方面具有很大的前景。
