Overview of Biomedical (Animal) In Vivo EPR
The use of in vivo EPR for experiments in
animals ranging in size from mice to pigs has proven to be very productive. In
order to obtain the most valid and relevant data possible, we have developed
techniques to ensure that the animals are under good physiological conditions
while the EPR measurements are being made and, also, that pertinent
physiological and other measurements can be made simultaneously.
As is the case for the clinical studies, the
studies in experimental animals have especially emphasized making repeated
measurements of oxygen in tissues. Using particulates for these studies
enables repeated measurements to made from the same site(s) over time,
including both continuous measurements for several hours and repeated
measurements for several months or even years. This has been usefully employed
in a large number of studies of tumors, brain, ischemia-reperfusion injury,
and responses to drugs and toxins. The oximetry technique with the particulate
also makes it feasible to make measurements at up to 36 sites in 3 cm sphere
by using magnetic field gradients and appropriate data processing techniques.
In vivo EPR also has been extensively
and productively employed in animals to measure other parameters that are
difficult to measure by others means. These include free radicals, molecular
motion, pH, the environment with drug implants, and redox status.
Information and illustrations of these and
other uses of in vivo EPR in animals are illustrated in the list of
publications and
research
highlights.
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