The effect of antioxidant treatment and NOS inhibition on the incidence of ischemia-induced arrhytmias in the diabetic rat heart

Title:

The effect of antioxidant treatment and NOS inhibition on the incidence of ischemia-induced arrhytmias in the diabetic rat heart

Creator:

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

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:1bd1a55d-9f07-4350-84e8-2797ac646606
uuid:1bd1a55d-9f07-4350-84e8-2797ac646606
issn:0862-8408

Subject:

Experimentální medicína, kardiovaskulární fyziologie, ischemie, srdeční arytmie, adaptace (biologie), cardiovascular physiology, ischemia, cardiac arrhythmia, adaptation (biology), myocardial ischemia, antioxidant treatment, 14, and 616-092

Type:

article, články, model:article, and TEXT

Format:

print, bez média, and svazek

Description:

Contrary to clinical trials, experimental studies revealed that diabetes mellitus (DM) may initiate, besides increased myocardial vulnerability to ischemia-reperfusion injury (I/R) and pro/antioxidant dysbalance, development of adaptation leading to an enhanced tolerance to I/R. The aims were to characterize 1) susceptibility to ischemia-induced ventricular arrhythmias in the diabetic rat heart 2) its response to antioxidant N-acetylcysteine (NAC ) and a NOS inhibitor L-NAME, and 3) the effect of DM on endogenous antioxidant systems. Seven days after streptozotocin injection (65 mg/kg, i.p.), Langendorff-perfused control (C) and DM hearts were subjected to 30-min occlusion of the LAD coronary artery with or without prior 15-min treatment with L-NAME (100 μM) or NAC (4 mM). Total number of ventricular premature beats (VPB), as well the total duration of ventricular tachycardia (VT) were reduced in the DM group (from 533±58 and 37.9±10.2 s to 224.3±52.6 and 19±13.5 s; P<0.05). In contrast to the antiarrhythmic effects of L-NAME and NAC in controls group (VPB 290±56 and 74±36, respectively; P<0.01 vs. control hearts), application of both drugs in the diabetics did not modify arrhythmogenesis (L-NAME: VPB 345±136, VT 25±13 s; NAC: VPB 207±50, VT 12±3.9 s; P>0.05 vs non-treated diabetic hearts). Diabetic state was associated with significantly elevated levels of CoQ 10 and CoQ 9 (19.6±0.8 and 217.3±9.5 vs. 17.4± 0. 5 and 185.0±5.0 nmol/g, respectively, in controls; P<0.05), as well as α-tocopherol (38.6±0.7 vs. 31.5±2.1 nmol/g in controls; P<0.01) in the myocardial tissue. It is concluded that early period of DM is associated with enhanced resistance to ischemia-induced arrhythmias. Diabetes mellitus might induce adaptive processes in the myocardium leading to lower susceptibility to antioxidant and L-NAME treatment., J. Matejíková, J. Kucharská, D. Pancza, T. Ravingerová., and Obsahuje bibliografii a bibliografické odkazy

Language:

English

Rights:

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

Source:

Physiological research | 2008 Volume:57 | Number:Suppl 2

Harvested from:

CDK

Metadata only:

false