Fig. 3.

PAI resolves interspecies differences in ODCs between mouse, rat, and human. Oxygenated mouse ($n=2$), rat ($n=4$), and human ($n=5$) blood samples were deoxygenated in a dynamic flow phantom circuit at room temperature and changes in absorption spectrum, ${\mathrm{pO}}_2$, and PAI signals were recorded. (a) Literature values for ODCs of the respective species under standard conditions.²⁶ (b) ${\mathrm{sO}}_2^{\mathrm{MSOT}}$ was calculated from PAI images using the absorption spectra measured within the flow phantom circuit for spectral unmixing. The resulting values were plotted against the measured ${\mathrm{pO}}_2$ of the blood within the circuit at the same time point in order to produce an ODC. (c) Extracted ${\mathrm{p}50}^{\mathrm{MSOT}}$ values denoting the ${\mathrm{pO}}_2$ at 50% ${\mathrm{sO}}_2^{\mathrm{MSOT}}$ are shown. It should be noted that the ODC influencing factors 2,3-DPG concentration, acid–base balance, and amount of dyshemoglobins were not standardized, but rather reflect the physiological values found in the respective species.