Mitochondrial Function in an In Vitro Model of Skeletal Muscle of Patients With Protracted Critical Illness and Intensive Care Unit-Acquired Weakness

Autor: Kateřina Jiroutková, Jan Gojda, Adéla Krajčová, Jakub Žiak, Martin Kalous, Jan Trnka, František Duška, Michal Fric, Valér Džupa, Jana Tůmová
Rok vydání: 2016
Předmět:
0301 basic medicine
Blood Glucose
Male
medicine.medical_specialty
medicine.medical_treatment
Critical Illness
Lipolysis
Muscle Fibers
Skeletal
Respiratory chain
Medicine (miscellaneous)
030204 cardiovascular system & hematology
Biology
Fatty Acids
Nonesterified
Quadriceps Muscle
Electron Transport
03 medical and health sciences
0302 clinical medicine
Insulin resistance
Intensive care
Internal medicine
medicine
Humans
Insulin
Respiratory system
Muscle
Skeletal
Beta oxidation
Aged
chemistry.chemical_classification
Nutrition and Dietetics
Muscle Weakness
Electron Transport Complex II
Skeletal muscle
Fatty acid
Middle Aged
medicine.disease
Adaptation
Physiological
Mitochondria
Muscle
Intensive Care Units
030104 developmental biology
medicine.anatomical_structure
Endocrinology
Biochemistry
chemistry
Female
Insulin Resistance
Energy Metabolism
Zdroj: JPEN. Journal of parenteral and enteral nutrition. 41(7)
ISSN: 1941-2444
Popis: BACKGROUND Functional mitochondria in skeletal muscle of patients with protracted critical illness and intensive care unit-acquired weakness are depleted, but remaining mitochondria have increased functional capacities of respiratory complexes II and III. This can be an adaptation to relative abundancy of fatty acid over glucose caused by insulin resistance. We hypothesized that the capacity of muscle mitochondria to oxidize fatty acid is increased in protracted critical illness. METHODS We assessed fatty acid oxidation (FAO) and mitochondrial functional indices in vitro by using extracellular flux analysis in cultured myotubes obtained by isolating and culturing satellite cells from vastus lateralis muscle biopsy samples from patients with ICU-acquired weakness (n = 6) and age-matched healthy controls (n = 7). Bioenergetic measurements were performed at baseline and after 6 days of exposure to free fatty acids (FFAs). RESULTS Mitochondrial density in myotubes from ICU patients was 69% of healthy controls ( P = .051). After adjustment to mitochondrial content, there were no differences in adenosine triphosphate (ATP) synthesis or the capacity and coupling of the respiratory chain. FAO capacity in ICU patients was 157% of FAO capacity in controls ( P = .015). In myotubes of ICU patients, unlike healthy controls, the exposure to FFA significantly ( P = .009) increased maximum respiratory chain capacity. CONCLUSION In an in vitro model of skeletal muscle of patients with protracted critical illness, we have shown signs of adaptation to increased FAO. Even in the presence of glucose and insulin, elevation of FFAs in the extracellular environment increased maximal capacity of the respiratory chain.
Databáze: OpenAIRE
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