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Kancirova 2016 Nove Strategicke Pristupy v experimentalnej Kardioprotekcii

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Kancirová I, Jašová M (2016) Mitochondrie ako hlavné efektory mechanizmov endogénnej ochrany myokardu. Nove Strategicke Pristupy v experimentalnej Kardioprotekcii 72-89.

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Kancirova I, Jasova M (2016) Nove Strategicke Pristupy v experimentalnej Kardioprotekcii 72-89

Abstract: Ischemic heart disease is one of the most frequent causes of severe myocardial injury occuring in the developed countries. Therefore, the emphasis is focused on the new possibilities of the cardioprotection usage in order to avoid the lethal heart injury and to improve its functional parameters. Different types of preconditioning preparing heart on the increased load induce protective functional and structural changes participating in processes of endogenous protection. The aim of our study was to elucidate the role of heart mitochondria as the final effector of noninvasive form of remote ischemic preconditioning applied at the distance location from the heart. Remote ischemic preconditioning consisted of three cycles of 5-minutes ischemia and 5-minutes reperfusion (200 mmHg) of the right hind limb using a pressure cuff. Mitochondria were isolated by differential centrifugation using the protease (P 6141) from the excited hearts subjected to ischemia-reperfusion Langendorff test (15 minutes of stabilization, 30 minutes of global ischemia, 40 minutes of reperfusion). Following parameters were determined in the isolated heart mitochondria: the activity of mitochondrial respiration using respirometer Oxygraph-2k (Oroboros Instruments, Austria), the mitochondrial ATP synthase activity determined as the amount of inorganic phosphate released by ATP splitting per unit of time, the mitochondrial membrane fluidity by spectrofluorometry using the fluorescent probe 1,6-diphenyl-1,3,5-hexatrien and the content of oxidised isoforms coenzyme Q(CoQ9ox) by HPLC method. Isolated heart exposed to ischemic-reperfusion injury resulted in a reduction of the mitochondrial ATP synthase activity as well as decrease in the ADP-stimulated respiration without affecting the basal mitochondrial respiration. Increase the content of coenzyme CoQ9ox oxidised isoforms reflecting respiratory chain damage during heart global ischemia and reperfusion accompanied by the mitochondrial membrane fluidity decrease. Remote ischemic preconditioning partly prevented the decrease of mitochondrial ATP synthase activity as well as decrease of ADP-stimulated respiration due to ischemia-reperfusion injury whereas the content of coenzyme CoQ9ox oxidized isoforms was increased after 15 minutes stabilization of ischemiareperfusion test. Mitochondrial membrane fluidity was increased in all phases of ischemia-reperfusion test. Despite of increased generation of free oxygen radicals during the stabilization phase, rigidization of the mitochondrial membrane was not observed. This findings suggest a signallig role of free oxygen radicals. Our results confirm damaging consequence of ischemia-reperfusion test on the functional and structural properties of the heart mitochondria. Remote ischemic preconditioning trought the generation of free oxygen radicals by the mitochondrial respiratory chain probably indicates the mechanisms of heart endogenous protection that lead to the alleviation of the lethal damaged induced by ischemic-reperfusion injury. Keywords: Remote ischemic preconditioning, Ischemia-reperfusion injury, Heart mitochondria, Respiratory chain, Free oxygen species, Mitochondrial membrane fluidity


Labels: MiParea: Respiration  Pathology: Cardiovascular  Stress:Ischemia-reperfusion  Organism: Rat  Tissue;cell: Heart  Preparation: Isolated mitochondria  Enzyme: Complex V;ATP synthase 

Coupling state: OXPHOS 

HRR: Oxygraph-2k 

2016-02