Nitric oxide involvement in the delayed antiarrhythmic effect of treadmill exercise in dogs

Hajnal, A.; Nagy, Orsolya; Litvai, Ágnes; Papp, Julius Gy.; Parratt, J. R.; Végh, Ágnes

doi:10.1016/j.lfs.2005.02.015

Cited by 16 publications

(17 citation statements)

References 35 publications

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“…Later this had been confirmed by studies using more selective inhibitors of iNOS [6,30,31,44]. For example, when aminoguanidine [31] and AEST [6] was administered prior to the occlusion in dogs that were subjected to cardiac pacing 24h previously, the antiarrhythmic protection was abolished.…”

Section: Mechanisms Involved In the Delayed Antiarrhythmic Protectionmentioning

confidence: 92%

“…Similarly, the repeated cardiac pacing-induced prolonged protection [6] as well as the heavy physical exercise-induced delayed antiarrhythmic effect [44] were both sensitive for selective (AEST) and non-selective (L-NAME) inhibitors of iNOS, indicating a role for iNOS activation in the development of the delayed cardioprotection.…”

Section: Mechanisms Involved In the Delayed Antiarrhythmic Protectionmentioning

confidence: 95%

“…Since these inhibitors are not entirely selective for iNOS, for example dexamethasone inhibits cox-2 as well [29], whereas L-NAME interferes NO formation resulting from activation of any NOS enzymes [44], the role for other isoforms of NO producing enzymes in the delayed phase of the protection can not be ruled out.…”

Section: Mechanisms Involved In the Delayed Antiarrhythmic Protectionmentioning

confidence: 99%

“…We have pharmacological evidence for this using various, more or less selective inhibitors of iNOS [6,29,31,44], which are all markedly attenuated or even abolished the delayed protection against arrhythmias resulted from cardiac pacing [6,29,31] or heavy physical exercise [44,70]. Since, these inhibitors are not entirely selective for iNOS the role of eNOS-derived NO formation in the delayed phase of the protection can not be ruled out.…”

Section: Effects Of Rapid Cardiac Pacing On Gene Expression Changesmentioning

confidence: 99%

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Changes in gene expression following cardiac pacing-induced delayed cardioprotection in the canine heart

Kovács¹,

Papp²,

Varga-Orvos³

et al. 2010

Acta Biologica Hungarica

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SUMMARYUnderstanding the mechanism behind the cardioprotection induced by preconditioning might provide a new therapeutic tool against the life threatening ventricular arrhythmias that often lead to sudden cardiac death.Therefore in Study I, we aimed to investigate gene expression changes following ischemia and reperfusion in dogs subjected to rapid right ventricular cardiac pacing 24 hours previously by a genome-wide approach using cDNA microarray analysis. We also aimed to examine the transcription rate of 45 additional genes which have already been suggested to be involved in ischemic PC but little is known about their role in the cardiac pacing induced antiarrhythmic protection. Furthermore, in Study II, 29 genes were selected to explore the time course changes of gene expressions over 24 hours, which elapses between rapid cardiac pacing and the ischemia/reperfusion period.In Study I, we have identified 23 genes with altered expression; some of these, for example, MEF2A (involved in angiogenesis) or mAKAP (an anchoring protein), were firstly demonstrated to be significantly up-regulated in response to preconditioning.We have proved that rapid right ventricular pacing alters the expression of genes involved in the delayed protection. In Study I, 6 out of 45 genes exhibited significant down-regulation and 16showed up-regulations in response to ischemia and reperfusion, compared with the control dogs. Among these, genes encoding different proteins, such as NO producing enzymes, heat shock proteins, members of the survival signaling pathways or pro-apoptotic factors showed the most marked changes. In Study II, we have proved that pacing induces time-dependent alterations in the expression of the 29 genes examined. Immediately after the cessation of pacing, 8 genes showed significant up-regulation and 6 significant down-regulation. After these initial changes, some of these early up-or down-regulated genes either remained unchanged or showed a biphasic transcriptional pattern; i.e. after an initial change in their transcription these genes were normalized to the mRNA level of the unpaced hearts but their expression started to change again at later time points. There were also genes, such as those encode eNOS and iNOS, which exhibited significant up-regulation only 12h after the pacing stimulus. The resultant increase in eNOS protein content and activation certainly contributes to an increased NO production, to which we attribute an important role in late phase of the protection. We are aware that changes at gene expression level do not always reflect changes at protein level, nevertheless the present results provide evidence for gene expression changes following cardiac pacing, and when the antiarrhythmic protection is observed.

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Section: Mechanisms Involved In the Delayed Antiarrhythmic Protectionmentioning

confidence: 92%

Section: Mechanisms Involved In the Delayed Antiarrhythmic Protectionmentioning

confidence: 95%

Section: Mechanisms Involved In the Delayed Antiarrhythmic Protectionmentioning

confidence: 99%

Section: Effects Of Rapid Cardiac Pacing On Gene Expression Changesmentioning

confidence: 99%

See 2 more Smart Citations

Changes in gene expression following cardiac pacing-induced delayed cardioprotection in the canine heart

Kovács¹,

Papp²,

Varga-Orvos³

et al. 2010

Acta Biologica Hungarica

Self Cite

View full text Add to dashboard Cite

show abstract

“…Studies have demonstrated that, remarkably, just one bout of aerobic exercise is sufficient to provide cardioprotection [7,8]. However, more comprehensive protection occurs after approximately 1 week of exercise training [9,10,11,12,13].…”

mentioning

confidence: 99%