XXII. BIOCHEMICKÝ ZJAZD - Jesseniova lekárska fakulta

Posters
4.
An anaLYSIS of THE IMPaCT of CNS ISCHEMIa ON MITOCHONDrial
rESPIraTOry COMPLEXES
Mária Chomová and Peter Račay
Institute of Medical Biochemistry, Jessenius Faculty of Medicine in Martin,
Comenius University in Bratislava
Mitochondria are responsible for aerobic respiration and ATP synthesis by oxidative
phosphorylation. In addition to being crucial for energy production and metabolic
pathways, they also play key roles in the signal cell network. Ischemia/reperfusion is
a multifactorial process that leads to disturbance of key mitochondrial functions and can
initiate a cascade of events, which result in tissue damage and finally in the cell death.
So the existence of mitochondrial signal network evokes numerous responses and effects,
which depend on the signal nature, cell environment and the individual ability of
the cell to deal with the signals. In this regard, the goal of the work was to contribute to
understanding the different processes in mitochondria after ischemic attack, particularly
in connection with mitochondrial respiratory complexes I and IV. The impact of 15 min
global brain ischemia followed by 1, 3, 24 and 72 hours reperfusion on complexes I and
IV in cortex and hippocampus was studied by spectrophotometric determination of their
enzymatic activities by using two electron acceptors, decylubichinone and ferricyanide
and two ways of membrane permeabilisation (sonification vs detergent). The noticed
variations were analyzed by electrophoretic methods SDS PAGE and two- dimensional
native BN PAGE/SDS PAGE. The posttranslation modifications of selected structural
subunits of respiratory complexes were monitored by Western blotting and immunodetection
of 3-nitrotyrosines as markers of oxidative damage to proteins. Add to this,
the interest was focused on processes of the p53-mitochondrial pathway of apoptosis
where the levels of p53 protein as well as pro- and antiapoptotic members of Bcl 2 family
were monitored. A possible involvement of the complex I structural subunit GRIM-19 in
apoptotic processes was also studied.
118 XXII. Biochemistry Congress, Martin