The Relationship between Frequency Dependence of Action Potential Duration and the Expression of TRPC3 in Rabbit Ventricular Myocardium

Wang, Yong; Chen, Mo-Si; Liu, Hongchang; Xiao, Junhua; Wang, Jialing

doi:10.1159/000358641

Cited by 12 publications

(7 citation statements)

References 27 publications

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“…Based on this observation we investigated the impact of alternating excitation directions on intrinsic FP features and identified significant differences. However, different beating rates lead to electrophysiological changes such as alteration of AP duration or upstroke velocity (29,42,51). To exclude beating-rate-induced effects, an analysis of the changes of the beating rate among competitive endogenous active pacemakers was performed showing, interestingly, almost similar frequencies.…”

Section: Discussionmentioning

confidence: 99%

Alterations of field potentials in isotropic cardiomyocyte cell layers induced by multiple endogenous pacemakers under normal and hypothermal conditions

Kienast

Stöger

Handler

et al. 2014

American Journal of Physiology-Heart and Circulatory Physiology

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The use of autonomous contracting randomly grown cardiomyocyte monolayers cultivated on microelectrode arrays (MEAs) represents an accepted experimental setting for preclinical experimental research in the field of cardiac electrophysiology. A dominant pacemaker forces a monolayer to adhere to a regular and synchronized contraction. Randomly distributed multiple pacemakers interfere with this dominant center, resulting in more or less frequent changes of propagation direction. This study aims to characterize the impact of changing propagation directions at single electrodes of the MEA on the four intrinsic parameters of registered field potentials (FPs) FPrise, FPMIN, FPpre, and FPdur and conduction velocity (CV) under normal and hypothermal conditions. Primary cultures of chicken cardiomyocytes (n = 18) were plated directly onto MEAs and FPs were recorded in a temperature range between 37 and 29°C. The number and spatiotemporal distribution of biological and artificial pacemakers of each cell layer inside and outside of the MEA registration area were evaluated using an algorithm developed in-house. In almost every second myocardial cell layer, interfering autonomous pacemakers were detected at stable temperatures, showing random spatial distributions with similar beating rates. Additionally, a temperature-dependent change of the dominant pacemaker center was observed in n = 16 experiments. A significant spread-direction-dependent variation of CV, FPrise, FPMIN, and FPpre up to 14% could be measured between different endogenous pacemakers. In conclusion, based on our results, disregarding the spatial origin of excitation may lead to misinterpretations and erroneous conclusions of FP parameters in the verification of research hypotheses in cellular electrocardiology.

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Section: Discussionmentioning

confidence: 99%

Alterations of field potentials in isotropic cardiomyocyte cell layers induced by multiple endogenous pacemakers under normal and hypothermal conditions

Kienast

Stöger

Handler

et al. 2014

American Journal of Physiology-Heart and Circulatory Physiology

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“…This finding suggests that chemerin protein caused no alteration in the Na + channel current during phase 0. On the other hand, MAP90 provides information about the repolarization phase of AP; it is inversely proportional to the number of heartbeats (30). The MAP90 showed a statistically insignificant change in the chemerin-treated groups compared with the control groups.…”

Section: Discussionmentioning

confidence: 99%

The Effect of Chemerin on Cardiac Parameters and Gene Expressions in Isolated Perfused Rat Heart

Kutlay¹,

Kaygisiz²,

Kaygisiz³

2019

Balkan Med J

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Background:Chemerin is a novel chemoattractant adipokine expressed in cardiovascular system, and its receptor has been detected in the epicardial adipose tissue.Aims:To determine the effects of chemerin on the cardiac parameters and gene expressions in the isolated perfused rat heart.Study Design:Animal experiment.Methods:The hearts were retrogradely perfused with Langendorff technique to measure the cardiac parameters. The experimental groups were acutely treated with 10, 100, and 1000 nM doses of chemerin. Another group was given 10 μM L-nitric oxide synthase inhibitor for 5 min before 1000 nM chemerin administration. The real-time polymerase chain reaction was performed for detecting the expression of target genes.Results:All doses of chemerin significantly decreased the left ventricular developed pressure (max 35.33 Δ%, p<0.001), and +dP/dtmax (max 31.3 Δ%, p<0.001), which are the indexes of cardiac contractile force. In addition, 1000 nM chemerin reduced the coronary flow (max 31 Δ%, p<0.001). N(W)-nitro-L-arginine methyl ester antagonized the negative inotropic effect of chemerin on contractility. Chemerin induced a 2.16-fold increase in endothelial nitric oxide synthase mRNA and increased the cyclic guanosine monophosphate levels (p<0.001) but decreased the PI3Kγ gene expression (1.8-fold, p<0.001). Furthermore, all doses of chemerin decreased the CaV1.2 gene expression (1.69-fold, p<0.001).Conclusion:Acute chemerin treatment induces a negative inotropic action with the involvement of nitric oxide pathway, CaV1.2, and PI3Kγ on isolated rat heart.

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“…It has been shown that MAPamp is formed due to the diffusion of Na + ions into the cell via voltage-gated Na + channels during the first phase of MAP (39). MAP 90 is inversely proportional to heart beats, and MAP duration is affected by the balance between inward depolarizing and outward repolarizing currents in the myocytes (40, 41). Our findings suggest that omentin does not influence these currents.…”

Section: Discussionmentioning

confidence: 99%

Effect of omentin on cardiovascular functions and gene expressions in isolated rat hearts

Kutlay

Kaygisiz²,

Kaygisiz³

2018

Anatol J Cardiol

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Objective: Omentin is a recently identified novel adipocytokine mainly expressed in the epicardial adipose tissue. Although it has favorable effects on cardiovascular disease, the impact of omentin on the hearts is still an understudied issue. The aim of the present study was to investigate the possible effects of omentin on isolated rat heart. Methods: Using the Langendorff method, 28 adult male Sprague–Dawley rat hearts were isolated and perfused with modified Krebs–Henseleit solution (mK–Hs). Concentrations of 100, 200, and 400 ng/mL omentin were given to the hearts for 30 min. The control group (n=7) was perfused with mK–Hs alone. Gene expressions in the left ventricle tissue were determined by real-time polymerase chain reaction. Left ventricular cyclic adenosine monophosphate and cyclic guanosine monophosphate (cGMP) concentrations were determined by using enzyme-linked immunosorbent assay. Results: All concentrations of omentin significantly decreased left ventricular developed pressure and maximal rate of pressure development that are the indexes of cardiac contractility. At the same time, omentin decreased both phosphoinositide 3-kinase γ (PI3Kγ) and sarcolemmal L-type Ca 2+ channel (CaV1.2) mRNA levels. Moreover, this peptide at concentrations of 200 and 400 ng/mL increased endothelial nitric oxide synthase (eNOS) mRNA. Furthermore, concentrations of 200 and 400 ng/mL omentin increased the amount of cGMP. Conclusion: We conclude that acute omentin treatment decreases cardiac contractility. Elevated eNOS mRNA and cGMP levels with reduced CaV1.2 mRNA are likely to lead to negative inotropy.

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The Relationship between Frequency Dependence of Action Potential Duration and the Expression of TRPC3 in Rabbit Ventricular Myocardium

Cited by 12 publications

References 27 publications

Alterations of field potentials in isotropic cardiomyocyte cell layers induced by multiple endogenous pacemakers under normal and hypothermal conditions

Alterations of field potentials in isotropic cardiomyocyte cell layers induced by multiple endogenous pacemakers under normal and hypothermal conditions

The Effect of Chemerin on Cardiac Parameters and Gene Expressions in Isolated Perfused Rat Heart

Effect of omentin on cardiovascular functions and gene expressions in isolated rat hearts

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