Protection against ischemia-induced ventricular arrhythmias and myocardial dysfunction conferred by preconditioning in the rat heart: Involvement of mitochondrial K ATP channels and reactive oxygen species

Title:

Protection against ischemia-induced ventricular arrhythmias and myocardial dysfunction conferred by preconditioning in the rat heart: Involvement of mitochondrial K ATP channels and reactive oxygen species

Creator:

Jana Matejíková, Jarmila Kucharská, Mária Pintérová, Dezider Pancza, and Ravingerová, T.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:cdd9b285-e63e-4282-b67b-52b3c88510e9
uuid:cdd9b285-e63e-4282-b67b-52b3c88510e9

Subject:

Fyziologie člověka a srovnávací fyziologie, fyziologie, srdeční arytmie, ischemická choroba srdeční, physiology, cardiac arrhythmia, ischemic heart disease, preconditioning, mito K ATP channels, rat heart, 14, and 612

Type:

article, články, model:article, and TEXT

Format:

print

Description:

a1_Ischemic preconditioning (I-PC) induced by brief episodes of ischemia and reperfusion (I/R) protects the heart against sustained I/R. Although activation of mitochondrial K ATP channels (mitoK ATP) interacting with reactive oxygen species (ROS) has been proposed as a key event in this process, their role in the antiarrhythmic effect is not clear. This study was designed: 1) to investigate the involvement of mito K ATP opening in the effect of I-PC (1 cycle of I/R, 5 min each) on ventricular arrhythmias during test ischemia (TI, 30-min LAD coronary artery occlusion) in Langendorff-perfused rat hearts and subsequent postischemic contractile dysfunction, and 2) to characterize potential mechanisms of protection confer red by I-PC and pharmacological PC induced by mito K ATP opener diazoxide (DZX), with particular regards to the modulation of ROS generation. Lipid peroxidation (an indicator of increased ROS production) was determined by measurement of myocardial concentration of conjugated dienes (CD) and thiobarbituric acid reactive substances (TBARS) in non-ischemic controls, non-preconditi oned and preconditioned hearts exposed to TI, I-PC alone, as well as after pretreatment with DZX, mito K ATP blocker 5-hydroxydecanoate (5-HD) and antioxidant N-acetylcysteine (NAC)., a2_Total number of ventricular premature beats (VPB) that occurred in the control hearts (518±71) was significantly (P<0.05) reduced by I-PC (195±40), NAC (290±56) and DZX (168±22). I-PC and NAC suppressed an increase in CD and TBARS caused by ischemia indicating lower production of ROS. On the other hand, I-PC and DZX themselves moderately enhanced ROS generation, prior to TI. Bracketing of I-PC with 5-HD suppressed both, ROS production during PC and its cardioprotective effect. In conclusion, potential mechanisms of protection conferred by mito K ATP opening in the rat heart might involve a temporal increase in ROS production in the preconditioning phase triggering changes in the pro/antioxidant balance in the myocardium and attenuating ROS production during subsequent prolonged ischemia., J. Matejíková ... [et al.]., and Obsahuje seznam literatury

Language:

English

Rights:

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

Source:

Physiological research | 2009 Volume:58 | Number:1

Harvested from:

CDK

Metadata only:

false