Mitochondrial cardiac response to hyperoxic hyperbaric treatment.

CZERNICZYNIEC, A.;; ROMERO FERNANDEZ, A. ; KARADAYIAN, A.; LORES ARNAIZ, S.; DI GIROLAMO, G.; COSTA, L.E.; LA PADULA, P.

Buenos Aires

Congreso; VI International Congress in Translational Medicine; 2023

The International Master in Biomedical Sciences (IMBS, Facultad de Farmacia y Bioquímica) and the Milstein-Köhler Binational PhD Program

Introduction: hyperoxia is defined as supraphysiologic oxygen concentrations at tissues and organs. The hyperoxic therapy (1.4-2.4 atm) is currently used as an adjunct therapy in many pathologies inducing vasoconstriction, reduction of inflammation and cardioprotection in the Langendorff rat model among other effects. In the present work we evaluated the mitochondrial oxygen consumption, reactive oxygen species (ROS) and nitric oxide (NO) production in cardiac left ventricle from male Sprague Dawley rats subjected to 30 sessions of 60 min in a hyperbaric chamber Revitalair® (Oxavita SRL) at 1.44 atm. and 100% O2. Results: basal oxygen consumption (without substrates) was similar in mitochondria from normoxic and hyperoxic animals. However, a differential respiratory response to TMPD/Ascorbate was observed in cardiac left ventricle mitochondria from experimental groups. Hyperoxic treatment increased 22% Complex IV associated- oxygen consumption (p < 0.05) compared with normoxic treatment. NO production was significantly decreased (51%) in cardiac left ventricle submitochondrial membranes from hyperoxic animals (p < 0.05). Accordingly, hyperoxic treatment increased cytochrome oxidase activity by 34% (p < 0.05), as compared with normoxic conditions. Also, ROS production significantly increased by 63% in mitochondria from animals submitted to hyperoxic conditions (p < 0.01) and a significant increase of 49 % in NADPH oxidase activity was observed in hyperoxic animals as compared with normoxic animals (p < 0.05).Conclusions: after a stimulus in the variation of the oxygen pressure in the inspired air, the left ventricle displays physiological adaptations at the mitochondrial level through a decrease in NO production with the consequent increase of oxygen consumption. Thus, a maximum oxygen uptake occurs in this hyperoxic atmosphere.