Publication de 4 numéros par an
ISSN Imprimer: 2155-014X
ISSN En ligne: 2155-0158
Mechanisms of Phase Changes in Energy Metabolism at Adaptation to Immobilization Stress: Role of Corticosterone
RÉSUMÉ
When stress affects the organs and tissues, barrier function of the lungs is disordered. It leads to a syndrome of "stress-induced lung" and a decrease of oxygen delivery to the tissues, as well as to tissue hypoxia. The aim of the study was to determine the dynamics of oxygen consumption, blood glucose, body temperature, activities of oxidant and antioxidant systems, as well as mitochondrial respiration under the influence of chronic stress (immobilization for 6 hours daily for 3 weeks on Wistar rats). Four phases in energy metabolism change have been identified in the dynamics of chronic stress. In the first phase, hypometabolic, instability of oxidative metabolism and decrease in oxidation of NAD-dependent substrates were observed, but significant elevation in FAD-dependent substrate oxidation and low mitochondrial respiratory uncoupling (MRU) were found. An increase in activity of mitochindrial manganese superoxide dismutase (MnSOD) occurs on the background of low glutathione peroxidase activity and misbalance of the antioxidant system. After seven immobilizations, shift in energy metabolism (second phase) occurs, and then the third phase (hypermetabolic) starts. The latter is characterized by a gradual increase in oxidative metabolism, the restoration of oxidation of NAD-dependent substrates, MRU, as well as optimizing balance of oxidant and antioxidant systems. The fourth phase occurs after 15 immobilization sessions, and it is characterized by the development of adaptive reactions, including increased tolerance of energy metabolism to the impact of immobilization. The results obtained correlate to changes in the dynamics of blood corticosterone. Thus, the phase character of the energy metabolism has been found during the chronic stress.