Málstofa Lífvísindaseturs - Hyperbaric oxygenation on vascular reactivity to angiotensin

Málstofa Lífvísindaseturs HÍ fimmtudaginn 11. apríl kl. 12:00 í Læknagarði, stofu 201

Fyrirlesari: Dr. Aleksandar Kibel, assistant professor at the Department of Physiology and Immunology at the Faculty of Medicine, University of Osijek, as well as an internal medicine specialist and cardiology subspecialist at the Department for Heart and Vascular Diseases, Osijek University Hospital, Croatia.

Titill: The effect of hyperbaric oxygenation on vascular reactivity to angiotensin II and angiotensin-(1-7) - the role of CYP enzymes

Ágrip: Hyperbaric oxygenation is the therapeutic or experimental application of 100% oxygen at a pressure level higher than atmospheric pressure. Treatment with hyperbaric oxygen can be a beneficial adjuvant therapy in various disorders characterized by compromised tissue oxygenation and perfusion. However, the effects of hyperbaric oxygenation cannot be simply explained as a compensation of the oxygen deficit. Hyperbaric oxygenation has a much broader influence and has the ability to alter protein expression, modulate signaling pathways and affect vascular structure and function. The objective of our work was to assess the effects of hyperbaric oxygenation on vascular reactivity to angiotensin II and angiotensin-(1-7) and to investigate the role of epoxyeicosatrienoic acids (EETs) and specific cytochrome P450 (CYP) enzymes in the modulation of vascular reactivity by hyperbaric oxygenation. Data from functional studies on isolated aortic ring preparations, as well as mRNA and protein expression studies will be presented, showing that hyperbaric oxygenation significantly increases vascular responses to ANG-(1-7), what could explain some of the observed positive effects of hyperbaric oxygenation in pathologic conditions. EETs seem to play an important role in the mechanism of this modulation. Hyperbaric oxygenation increases the expression of specific CYP isoforms, but it is also possible that it increases the vascular sensitivity to EETs. The changes in vascular reactivity were not a consequence of a possible change in arterial pressure, oxidative stress or ANG-(1-7) blood levels. Hyperbaric oxygenation does not significantly alter reactivity to ANG II in either healthy or diabetic rats. The findings contribute in broadening our understanding of the mechanisms underlying the influence of hyperbaric oxygenation.

Starfsferill: Aleksandar Kibel is assistant professor at the Department of Physiology and Immunology at the Faculty of Medicine, University of Osijek, as well as an internal medicine specialist and cardiology subspecialist at the Department for Heart and Vascular Diseases, Osijek University Hospital, Croatia. He graduated from the Faculty of Medicine, University of Osijek with an MD degree in 2009. with a maximum possible grade average, conducting experimental research activities during almost all study years and receiving awards that include the country's top scholarship („Top scholarship for top students“). Research activities included laboratory practicums and research visits at a number of foreign institutions including the University Clinic Hamburg-Eppendorf (Germany), the Medical College of Wisconsin (USA), Chulalongkorn University in Bangkok (Thailand) etc. He obtained his PhD degree at the Department of Physiology and Immunology with a focus on vascular physiology and pathophysiology and teaches at the medical high school-, university- and postgraduate doctoral levels. He is now mentor on several diploma works. Prior work experience also includes work at the Emergency medicine department and an internship at the University Hospital Zagreb, as well as volunteer work at the Red Cross. He published a number of scientific papers, three book chapters, actively participated in many international scientific conferences, actively participated in research projects at the pre-clinical and clinical levels, as well as in pharmacological clinical trials as sub-investigator. He is guest editor of two special issues in the Journal of International Medical Research, lead guest editor of a special issue of the journal Oxidative Medicine and Cellular Longevity and is editorial board member several other journals. He is head of the MEFOS-2 research group of the "Scientific Excellence Center for the production and investigation of functional foods" (ZCI), Croatia, investigating the influence of functional food on microvascular function in cardiovascular patients.