Reduced susceptibility to ischemia-induced arrhythmias in the preconditioned rat heart is independent of PI3-kinase/Akt

Title:

Reduced susceptibility to ischemia-induced arrhythmias in the preconditioned rat heart is independent of PI3-kinase/Akt

Creator:

Ravingerová, T., Jana Matejíková, Dezider Pancza, and František Kolář

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:67b0ebdc-665c-468c-921d-fcf48e93adba
uuid:67b0ebdc-665c-468c-921d-fcf48e93adba
issn:0862-8408

Subject:

Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, myocardial ischemia, arrhythmias, preconditioning, PI3-kinase/Akt, rat heart, 14, and 612

Type:

article, články, model:article, and TEXT

Format:

print, bez média, and svazek

Description:

We examined the involvement of phosphatidylinositol 3-kinase (PI3K) and its effector protein ki nase B (Akt) in cardioprotective effects of ischemic preconditioning (PC) with particular regards to its role in the protection against ischemia-induced arrhythmias in isolated perfused rat heart. PI3K/Akt inhibitor wortmannin (100 nM) was administered 15 min prior to 30-min regional (left anterior descending coronary artery occlusion) ischemia for the study of ischemic arrhythmias in the hearts perfused at constant coronary flow or prior to 30-min global ischemia followed by 2-h reperfusion for the infarct size (IS) determination (tetrazolium staining) in the hearts perfused at constant pressure. PC procedure (one cycle of isch emia/reperfusion, 5 min each) significantly reduced the total number of ventricular premature complexes (PVC) and severity of arrhythmias (arrhythmia score; AS) over the whole period of left anterior descending coronary artery occlusion in comparison with non-PC controls (PVC 166±40; AS 1.6±0.2 vs . 550±60 and 3.2±0.2; respectively; P<0.05). In a setting of global ischemia/reperfusion, PC decreased IS (in % of the left ventricle, LV) by 73 %. Pretreatment with wortmannin modified neither arrhythmogenesis nor IS in the non-PC hearts. Bracketing of PC with wortmannin did not abolish antiarrhythmic protection (PVC 92±25; AS 1.7±0.2; P<0.05 vs . non-PC hearts). On the other hand, wortmannin increased IS/LV in the PC hearts to 24±1.2 % as compared with 9 ± 0.6 % in the untreated ones (P<0.05). In conclusion, PI3K/Akt inhibition did not affect reduced arrhythmogenesis during ischemia in the PC hearts indicating that in contrast to its positive role in the irreversible myocardial injury, PI3K/Akt activity is not required for protection induced by PC against ischemic arrhythmias in the rat heart., T. Ravingerová, J. Matejíková, D. Pancza, F. Kolář., and Obsahuje bibliografii

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 2009 Volume:58 | Number:3

Harvested from:

CDK

Metadata only:

false