Abstract:
:EPR oximetry is a promising, relatively non-invasive method for monitoring the partial pressure of oxygen in tissue (PtO2) that has proved useful in following changes under various physiologic and pathophysiologic conditions. Optimal utilization of the method will be facilitated by systematic comparisons with other available methods. Here we report on the absolute values of rat brain PtO2 using EPR and the more widely used Eppendorf polarographic microelectrode system in the same brain. EPR used an L-band (1.2 GHz) spectrometer and implanted lithium phthalocyanine (LiPc) as the oxygen-sensitive paramagnetic material. Eppendorf measurements were made by a needle probe moved vertically through the cortex at 0.5 mm intervals in three tracks including one adjacent to the location of the LiPc. Several conclusions were drawn, including, (1) the average PtO2 measured by the two methods was similar but EPR reported a significantly higher average PtO2, (2) there was poor correlation between the values in the same animal on the same side of the brain, (3) the Eppendorf reported a larger range of values and (4) the heterogeneity of oxygen levels in the brain and the areas sampled by the two methods provide an adequate explanation for the observed differences.
journal_name
Physiol Measjournal_title
Physiological measurementauthors
O'Hara JA,Khan N,Hou H,Wilmo CM,Demidenko E,Dunn JF,Swartz HMdoi
10.1088/0967-3334/25/6/007subject
Has Abstractpub_date
2004-12-01 00:00:00pages
1413-23issue
6eissn
0967-3334issn
1361-6579journal_volume
25pub_type
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