Adéla Krajčová1,2,3, Nils Gunnar Løvsletten4, Petr Waldauf1, Vladimír Frič5, Moustafa Elkalaf2,3, Tomáš Urban1, Michal Anděl2, Jan Trnka2,3, G Hege Thoresen4, František Duška1. 1. Department of Anaesthesia and Intensive Care of Královské Vinohrady University Hospital and The Third Faculty of Medicine, OXYLAB-Laboratory for Mitochondrial Physiology, Charles University, Prague, Czech Republic. 2. Centre for Research on Diabetes, Metabolism and Nutrition of Third Faculty of Medicine, Charles University, Prague, Czech Republic. 3. Laboratory for Metabolism and Bioenergetics, The Third Faculty of Medicine, Charles University, Prague, Czech Republic. 4. Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway. 5. Department of Orthopaedics and Traumatology, Královské Vinohrady University Hospital and The Third Faculty of Medicine, Charles University, Prague, Czech Republic.
Abstract
OBJECTIVES: Propofol may adversely affect the function of mitochondria and the clinical features of propofol infusion syndrome suggest that this may be linked to propofol-related bioenergetic failure. We aimed to assess the effect of therapeutic propofol concentrations on energy metabolism in human skeletal muscle cells. DESIGN: In vitro study on human skeletal muscle cells. SETTINGS: University research laboratories. SUBJECTS: Patients undergoing hip surgery and healthy volunteers. INTERVENTIONS: Vastus lateralis biopsies were processed to obtain cultured myotubes, which were exposed to a range of 1-10 μg/mL propofol for 96 hours. MEASUREMENTS AND MAIN RESULTS: Extracellular flux analysis was used to measure global mitochondrial functional indices, glycolysis, fatty acid oxidation, and the functional capacities of individual complexes of electron transfer chain. In addition, we used [1-C]palmitate to measure fatty acid oxidation and spectrophotometry to assess activities of individual electron transfer chain complexes II-IV. Although cell survival and basal oxygen consumption rate were only affected by 10 μg/mL of propofol, concentrations as low as 1 μg/mL reduced spare electron transfer chain capacity. Uncoupling effects of propofol were mild, and not dependent on concentration. There was no inhibition of any respiratory complexes with low dose propofol, but we found a profound inhibition of fatty acid oxidation. Addition of extra fatty acids into the media counteracted the propofol effects on electron transfer chain, suggesting inhibition of fatty acid oxidation as the causative mechanism of reduced spare electron transfer chain capacity. Whether these metabolic in vitro changes are observable in other organs and at the whole-body level remains to be investigated. CONCLUSIONS: Concentrations of propofol seen in plasma of sedated patients in ICU cause a significant inhibition of fatty acid oxidation in human skeletal muscle cells and reduce spare capacity of electron transfer chain in mitochondria.
OBJECTIVES:Propofol may adversely affect the function of mitochondria and the clinical features of propofol infusion syndrome suggest that this may be linked to propofol-related bioenergetic failure. We aimed to assess the effect of therapeutic propofol concentrations on energy metabolism in human skeletal muscle cells. DESIGN: In vitro study on human skeletal muscle cells. SETTINGS: University research laboratories. SUBJECTS:Patients undergoing hip surgery and healthy volunteers. INTERVENTIONS: Vastus lateralis biopsies were processed to obtain cultured myotubes, which were exposed to a range of 1-10 μg/mL propofol for 96 hours. MEASUREMENTS AND MAIN RESULTS: Extracellular flux analysis was used to measure global mitochondrial functional indices, glycolysis, fatty acid oxidation, and the functional capacities of individual complexes of electron transfer chain. In addition, we used [1-C]palmitate to measure fatty acid oxidation and spectrophotometry to assess activities of individual electron transfer chain complexes II-IV. Although cell survival and basal oxygen consumption rate were only affected by 10 μg/mL of propofol, concentrations as low as 1 μg/mL reduced spare electron transfer chain capacity. Uncoupling effects of propofol were mild, and not dependent on concentration. There was no inhibition of any respiratory complexes with low dose propofol, but we found a profound inhibition of fatty acid oxidation. Addition of extra fatty acids into the media counteracted the propofol effects on electron transfer chain, suggesting inhibition of fatty acid oxidation as the causative mechanism of reduced spare electron transfer chain capacity. Whether these metabolic in vitro changes are observable in other organs and at the whole-body level remains to be investigated. CONCLUSIONS: Concentrations of propofol seen in plasma of sedated patients in ICU cause a significant inhibition of fatty acid oxidation in human skeletal muscle cells and reduce spare capacity of electron transfer chain in mitochondria.
Authors: Ryan Atkins; Dumitru Constantin-Teodosiu; Krishna K Varadhan; Despina Constantin; Dileep N Lobo; Paul L Greenhaff Journal: Clin Nutr Date: 2020-07-14 Impact factor: 7.324