Mark Wefers Bettink

Monitoring mitochondrial respiration 5 89 Preparation ALA application Preparation ALA application LPS infusion Fluid resuscitation time (min) 60 120 180 240 300 360 - 450 M-TC M-LPS NaCl infusion Preperation ALA application TC Succinate infusion Preperation ALA application SC NaCl infusion LPS infusion Preperation ALA application LPS-- NaCl infusion Preperation ALA application LPS+- Succinate infusion Preperation ALA application time (min) 60 120 180 240 300 360 LPS infusion Fluid Resucitation LPS infusion Fluid Resucitation LPS++ T0 T1 Muscle biopsy Muscle biopsy T0 T1 A B Figure 1. Schematic timeline of the experimental protocol. Panel A: Experiment A. with muscle measurement. M-TC: time control, M-LPS: endotoxemia with fluid resuscitation. Panel B: Experiment B. without muscle measurement. TC; time control, SC; succinate control, LPS --; endotoxemia, LPS +-; endotoxemia with fluid resuscitation, LPS ++; endotoxemia with fluid resuscitation and succinate. ALA; 5- aminolevulinic acid, LPS; lipopolysaccharide, T0 and T1 are the time points of mitoPO2 and ODR measurement. The oxygen disappearance rate is measured directly after local occlusion of the oxygen supply. The reflection probe was mounted on a height-adjustable frame, above the ALA-treated skin, providing different settings of the probe distances to the skin. Local occlusion of the microcirculation in the skin was obtained by local pressure with the measurement probe. This simple procedure created reproducible stop-flow conditions and induced measurable oxygen disappearance rates, due to cessation of microvascular oxygen supply and ongoing cellular oxygen consumption. MitoPO 2 was measured before,