Comparison of tumor and normal tissue oxygen tension measurements using OxyLite or microelectrodes in rodents

RD Braun, JL Lanzen, SA Snyder… - American Journal of …, 2001 - journals.physiology.org
RD Braun, JL Lanzen, SA Snyder, MW Dewhirst
American Journal of Physiology-Heart and Circulatory Physiology, 2001journals.physiology.org
In this study we compare oxygen tension (Po 2) histograms measured with O2
microelectrodes and a new optical Po 2 measurement device, the OxyLite, in normal tissues
(mouse spleen and thymus) and in tumors (R3230Ac in rats)(n= 5–6). The transient
response to glucose infusion or 100% O2 breathing (hyperoxia) was also measured in
tumors. Po 2 histograms of spleen and thymus with the two devices were not different. The
OxyLite tumor Po 2 histogram, however, was left-shifted compared with the microelectrode …
In this study we compare oxygen tension (Po 2) histograms measured with O2 microelectrodes and a new optical Po 2 measurement device, the OxyLite, in normal tissues (mouse spleen and thymus) and in tumors (R3230Ac in rats) (n = 5–6). The transient response to glucose infusion or 100% O2 breathing (hyperoxia) was also measured in tumors. Po 2 histograms of spleen and thymus with the two devices were not different. The OxyLite tumor Po 2 histogram, however, was left-shifted compared with the microelectrode (median Po 21.0 vs. 4.0 mmHg, P = 0.016). Both probes responded to acute hyperglycemia with a mean increase of 3–6 mmHg, but the microelectrode change was not significant. The OxyLite consistently recorded large Po 2 increases (∼28 mmHg) with hyperoxia, whereas the microelectrode response was variable. The OxyLite averages Po 2 over an area that contains interstitial and vascular components, whereas the microelectrode measures a more local Po 2. This study demonstrates the importance of considering the features of the measurement device when studying tissues with heterogeneous Po 2 distributions (e.g., tumors).
American Physiological Society