Mark Wefers Bettink

Chapter 5 94 ODR measurements ODR was derived from the mitoPO 2 slope during blockage of microcirculatory blood flow. At T0 the initial mitoPO 2 was approximately 60 mmHg. Blocking the microcirculation by local pressure with the measurement probe caused a drop in mitoPO 2 from 55 mmHg to approximately 10 mmHg in 10 s, this resulted in a ODR of 5.8 mmHg*s -1 (Fig. 3). In experiment A, at baseline no difference was found in skin and muscle between M-TC and M-LPS group (figure 2A and B). In contrast, at T1, a significant lower value was measured in skin (LPS; -4.2 [3.0] mmHg*s - 1 vs TC; -7.1 [1.5] mmHg*s -1 ) and in muscle (LPS -6.7 [2.4] mmHg*s -1 vs TC -9.7 [0.5] mmHg*s -1 ) (Fig. 2B). Figure 3. Typical example of in vivo mitochondrial respirometry measured at T0 on the abdominal skin of a rat. The ODR was determined from the linear part of the oxygen disappearance curve by fitting equation 2. MitoPO 2 was the mean mitoPO 2 before the start of tissue compression. Mitochondrial assay in muscle biopsies Muscle biopsies were performed at the end of the experiment. We found no difference in complex 1 and 2 activity in the high-resolution respirometer of the homogenized muscle in both groups, as shown in figure 2C. We found no difference in complex activity corrected for citrate synthase activity measured in the snap frozen biopsies.