Program and book of abstracts 1st conference

1 st Conference of European Academy for Molecular Hydrogen Research in Biomedicine “Hydrogen for Biomedicine“

Kalocayova Barbora

EFFECT OF MOLECULAR HYDROGEN ON CARDIAC SURGERY-ASSOCIATED ACUTE KIDNEY INJURY Barbora Kalocayova 1 , Branislav Kura 1 , Jana Vlkovicova 1 , Denisa Snurikova 1 , Norbert Vrbjar 1 , Karel Frimmel 1 , VladanHudec 2 ,Matej Ondrusek 2 , IvoGasparovic 2 , Rastislav Sramaty 2 , Jaroslav Luptak 2 , Michal Hulman 2 , Jan Slezak 1 1 Centre of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovakia, 2 Department of Cardiac Surgery, Faculty of Medicine, National Institute of Cardiovascular Diseases, Bratislava, Slovakia, BACKGROUND: Cardiac surgery-associated acute kidney injury (CS-AKI) is common postoperative complication following cardiac surgery. Since oxidative stress is hypothesized to be one of the causes of CS-AKI, molecular hydrogen (H2) supplementation has been proposed as a novel and promising antioxidant for the prevention of CS-AKI. Our study was performed on an in vivo model of simulated porcine heart transplantation. METHODS: Animals in the H2 group received H2 in gaseous form (3%) during inhalation of anesthesia and throughout oxygenation of blood in extracorporeal circulation. The levels of creatinine, urea, and phosphorus weremeasured in plasma. Renal tissue samples were analyzed by the Western blot method (Nrf2; Keap-1; SOD) as well as by measuring enzyme kinetics of Na,K-ATPase. After cardiac surgery selected plasma biomarkers were elevated. RESULTS:The use of H2 was followed by the normalization of all these parameters. Our results suggest activation of Nrf2/Keap1 pathway as well as increased SOD protein expression in the H2-treated group. Regarding Na,K-ATPase we detected a significant decrease of the Vmax in the H2 group. Our results support the effectiveness of H2 supplementation in CS-AKI, especially in terms of normalization of plasma biomarkers to control levels. CONCLUSION:The protective effect of H2might be linked to its activity against oxidative stress via Nrf2/Keap1 pathway modulation. H2 treatment resulted in decrease in renal Na,K-ATPase activity indicating decreased sodium reabsorption, which appears to be a novel regulatory mechanismof an important membrane transporter during CS-AKI in the H2-treated pigmodel. Keywords: Molecular hydrogen, Kidney injury, Cardiac surgery, Oxidative stress Funding: APVV-15-0376, APVV-19-0317, ITMS 26230120009, 2018/7838:1-26C0, 2019/4-CEMSAV1, VEGA 2/0063/18, 2/0092/22 and 2/0148/22. MSc. Barbora Kaločayová, Ph.D. is a young independent scientist currently investigating the role of Na, K-ATPase in the heart, kidneys, and various parts of the brain. She is a co-investigator of 2 VEGA projects in this area. Dr. Kaločayová successfully participated in COST projects (CA16225: EU-CARDIOPROTECT, CA17129: EUCardioRNA). She participated in the foreign research stays at Semmelweis University, the Faculty of Medicine, the Department of Pharmacology and Pharmacotherapy, Budapest, Hungary, and at the Luxembourg Institute of Health in Luxembourg. She is the holder of a Stefan Schwarz scholarship. She is currently engaged in biomedical research of of molecular hydrogen in conditions of increased production of free oxygen radicals (radiationmodel - rats, model of simulated heart transplantation - pigs).

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