It is a well-known fact that the oxygenation level is a significant determinant when it comes to identifying and monitoring neoplastic changes. Another fact is that anesthetics affect the physiology of the oxygen inside the animal’s body, which could cause inaccuracies during in vivo experiments. The question is whether it is possible to monitor conscious animal, avoiding the anesthesia’s impact and, simultaneously, collect high-quality data.
To answer this question, we begin by taking a closer look at the study conducted by Matsumoto et al. “Dynamic Monitoring of Localized Tumor Oxygenation Changes Using RF Pulsed Electron Paramagnetic Resonance in Conscious Mice”.
The authors used an electron paramagnetic resonance (EPR) spectroscopy at frequency of 750 MHz to assess the pO2 level in tumor bearing mice. Crystals of lithium phthalocyanine (LiPc) was implanted into squamous cell carcinoma (SCC) tumor and femoral muscle on opposing legs of mice. It has been examined whether there is a correlation between oxygenation and factors such as anesthesia, body temperature and carbogen inhalation. As a consequence of the conducted experiment, this correlation has been confirmed by Matsumoto and colleagues.
In conclusion, EPR spectroscopy, due to a rapid acquisition of spectral data, enables the pO2 measurements in conscious mice and minimizing the influence of anesthetics. This ability makes the EPR with LiPc a powerful tool in oncology researches, especially. in studies on tissues oxygenation.
Matsumoto S. et al.; Dynamic monitoring of localized tumor oxygenation changes using RF pulsed electron paramagnetic resonance in conscious mice; Magn Reson Med. 2008 Mar;59(3):619-25; DOI: 10.1002/mrm.21500.