Visit our Expo - Redox and Inflammation signaling 2012

Session XI: Cell death and cardiovascular diseases Poster XI, 3
Role of urocortin in early myocardial pre- and postconditioning
Barbara Cserepes, Boglarka Racz, Balazs Gasz, Andrea Ferencz, Maria Kurthy, Janos
Lantos, Gabor Jancso, Erzsebet Roth
Department of Surgical Research and Techniques, Medical Faculty, University of Pecs,
Hungary. E-mail: barbicska@yahoo.co.uk
Pre- and postconditioning are powerful endogenous adaptive phenomenon of the organism
whereby different stimuli (hypoxia, drugs, hypotermia) enhance the tolerance against various
types of stress. Urocortin, member of the corticotrophin-releasing factor family has potent
effects on the cardiovascular system including vasodilation, increases in coronary blood flow
and cardiac contractility, and induces protection against ischaemia/reperfusion damage.
Recent studies reported that urocortin has similar cardioprotective effects as the ischaemic
preconditioning in both early and delayed phases. The aim of this study was to investigate the
effect of urocortin on cultured cardiomyocytes in the process of pre– and postconditioning.
Isolated neonatal rat ventricular myocytes were preconditioned with adenosine, simulated
ischaemia and urocortin (10 minutes treatment followed by 10 minutes
reperfusion/resolution). For detecting the effect of alternative types of preconditioning,
necrosis enzyme (LDH) release, vital staining (trypan blue) and ratio of apoptosis/necrosis
were examined after cardiac cells were exposed to 3 hours sustained ischaemia and 2 hours
reperfusion. Same parameters were measured in the postconditioned groups (30 or 60 minutes
ischaemia followed by postconditioning with 10 min ischaemic stimulus or urocortin and 2
hours reperfusion). Cells exposed to 3 h ischaemia followed by 2 h reperfusion were shown as
control.
Our results show, that LDH release and the ratio of necrotised cells was decreased, but
proportion of alive/dead myocytes was increased in all preconditioned groups compared with
control group. In postconditioned groups LDH content of culture medium, number of trypan
blue-stained cells was reduced, rate of apoptotic/necrotic cells was raised contrasted with non
postconditioned group, and the difference was more expressed in urocortin treated group after
60 min ischaemia.
We can conclude that urocortin might play an important role in myocardial cytoprotection.
Preconditioning with urocortin induced such a powerful cell protective effect as adenosine
and ischaemia. Furthermore, postconditioning with urocortin after 60 min ischaemia was
more cardioprotective than ischaemic postconditioning. Supported by the Hungarian
Scientific Research Foundation (OTKA) T-048851, T-038035, F046593.
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