Microcirculatory and Mitochondrial PO2 in different (Patho-)Physiological states of the rat heart

Handling and availability issues of oxygen are relevant processes fueling evolution of several diseases. Measuring oxygen in organs, at cellular and subcellular level bears several challenges. Earlier our group had developed dual-wavelength phosphorimeter allowing measurements of microcirculatory PO2 at two depths. Then, adaptation of this technique made the measurement of mitochondrial pO2 possible. The next logic step accomplished in this thesis was to combine both techniques.
The aim of the thesis was therefore to further develop and characterize this phosphorimetric method of near-simultaneous measurements of microcirculatory and mitochondrial oxygenation in the heart in vivo. Then in two animal models, namely endotoxemia and right ventricular pressure overload, we measured the oxygenation level in the microcirculation and mitochondria and investigated the changes induced by therapeutic interventions. We hypothesized that in sepsis hypoxia would be found in non-resuscitated animals but no oxygen shortage would be found with supportive therapy indicating oxygen management issues arising from mitochondrial dysfunction. In pressure overload induced right heart failure we expected a switch increased anaerobic glycolysis without occurrence of hypoxia.