Rat caval vein myocardium undergoes changes in conduction characteristics during postnatal ontogenesis

Ivanova, Angelina; Samoilova, Daria V.; Razumov, Artem; Kuzmin, Vladislav S.

doi:10.1007/s00424-019-02320-0

Cited by 5 publications

(8 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This study aims to investigate the cellular and ion mechanisms that underlie the effects of α‐adrenergic stimulation in the caval vein myocardium. The myocardial sleeves are well developed in the rat SVC wall 8,27 . The present study provides the first functional comparison of the inward rectifier currents (I K1 ) and the expression of I K1 channel‐forming subunit in rat SVC and working atrial myocardium.…”

Section: Introductionmentioning

confidence: 85%

“…The myocardial sleeves are well developed in the rat SVC wall. 8,27 The present study provides the first functional comparison of the inward rectifier currents (I K1 ) and the expression of I K1 channel-forming subunit in rat SVC and working atrial myocardium. In addition, this study demonstrates that α-adrenergic downregulation of I K1 current causes an instability of the resting membrane potential (RMP) and facilitates proarrhythmic conduction of excitation in the SVC myocardial tissue.…”

Section: Introductionmentioning

confidence: 94%

“…[1][2][3][4] The myocardial tissue of the thoracic veins is functionally active, able to generate action potentials (APs) and to conduct the excitation. [5][6][7][8][9] For the last two decades, the thoracic vein myocardium has been under scrutiny as a result of the consideration of this tissue as the main source of ectopic activity that provokes atrial fibrillation (AF). It was established that in the majority of clinical cases, the proarrhythmic activity origins in PV myocardium, 10 while in 28% of cases, the AF is caused by «non-pulmonary» ectopic activity, including fibrillation derived from the caval veins.…”

Section: Introductionmentioning

confidence: 99%

“…Depending on the animal species, myocardial coating might be found in pulmonary veins (PV), superior right (SVC) and left (if present) caval veins, azygos vein and rarely in inferior vena cava 1‐4 . The myocardial tissue of the thoracic veins is functionally active, able to generate action potentials (APs) and to conduct the excitation 5‐9 . For the last two decades, the thoracic vein myocardium has been under scrutiny as a result of the consideration of this tissue as the main source of ectopic activity that provokes atrial fibrillation (AF).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Attenuation of inward rectifier potassium current contributes to the α1‐adrenergic receptor‐induced proarrhythmicity in the caval vein myocardium

et al. 2020

Self Cite

View full text Add to dashboard Cite

Aim This study is aimed at investigation of electrophysiological effects of α1‐adrenoreceptor (α1‐AR) stimulation in the rat superior vena cava (SVC) myocardium, which is one of the sources of proarrhythmic activity. Methods α1‐ARs agonists (phenylephrine—PHE or norepinephrine in presence of atenolol—NE + ATL) were applied to SVC and atrial tissue preparations or isolated cardiomyocytes, which were examined using optical mapping, glass microelectrodes or whole‐cell patch clamp. α1‐ARs distribution was evaluated using immunofluorescence. Kir2.X mRNA and protein level were estimated using RT‐PCR and Western blotting. Results PHE or NE + ATL application caused a significant suppression of the conduction velocity (CV) of excitation and inexcitability in SVC, an increase in the duration of electrically evoked action potentials (APs), a decrease in the maximum upstroke velocity (dV/dtmax) and depolarization of the resting membrane potential (RMP) in SVC to a greater extent than in atria. The effects induced by α1‐ARs activation in SVC were attenuated by protein kinase C inhibition (PKC). The whole‐cell patch clamp revealed PHE‐induced suppression of outward component of IK1 inward rectifier current in isolated SVC, but not atrial myocytes. These effects can be mediated by α1A subtype of α‐ARs found in abundance in rat SVC. The basal IK1 level in SVC was much lower than in atria as a result of the weaker expression of Kir2.2 channels. Conclusion Therefore, the reduced density of IK1 in rat SVC cardiomyocytes and sensitivity of this current to α1A‐AR stimulation via PKC‐dependent pathways might lead to proarrhythmic conduction in SVC myocardium by inducing RMP depolarization, AP prolongation, CV and dV/dtmax decrease.

show abstract

Section: Introductionmentioning

confidence: 85%

Section: Introductionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Attenuation of inward rectifier potassium current contributes to the α1‐adrenergic receptor‐induced proarrhythmicity in the caval vein myocardium

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…It has been demonstrated in many species including rats that both PV and SVC myocardium in adult animals is characterized by an unstable and depolarized RMP level if compared to atrial myocardium (Ito et al 1967;Tsuneoka et al 2012;Ivanova et al 2019). The low density of the Kir2.X channels and inwardly rectifier I K1 (Chen et al 2001(Chen et al , 2002aTsuneoka et al 2017), increased resting Na + permeability (Malécot et al 2015) and enhanced chloride conduction (Okamoto et al 2014) are suggested as the mechanisms responsible for a reduced RMP in PV.…”

Section: Developmental Changes Of the Resting Membrane Potential In Svc And Pv Myocardiummentioning

confidence: 99%

The susceptibility of the rat pulmonary and caval vein myocardium to the catecholamine‐induced ectopy changes oppositely in postnatal development

Kuzmin

Ivanova

Потехина

et al. 2021

The Journal of Physiology

Self Cite

View full text Add to dashboard Cite

The developmental changes of the caval (SVC) and pulmonary vein (PV) myocardium electrophysiology are traced throughout postnatal ontogenesis.r The myocardium in SVC as well as in PV demonstrate age-dependent differences in the ability to maintain resting membrane potential, to manifest automaticity in a form of ectopic action potentials in basal condition and in responses to the adrenergic stimulation.r Electrophysiological characteristics of two distinct types of thoracic vein myocardium change in an opposite manner during early postnatal ontogenesis with increased proarrhythmicity of pulmonary and decreased automaticity in caval veins.r Predisposition of PV cardiac tissue to proarrhythmycity develops during ontogenesis in time correlation with the establishment of sympathetic innervation of the tissue.r The electrophysiological properties of caval vein cardiac tissue shift from a pacemaker-like phenotype to atrial phenotype in accompaniment with sympathetic nerve growth and adrenergic receptor expression changes.

show abstract

α1-adrenergic receptors accompanied by GATA4 expression are related to proarrhythmic conduction and automaticity in rat interatrial septum

Pustovit

Samoilova²,

Abramochkin

et al. 2022

J Physiol Biochem

View full text Add to dashboard Cite

Rat caval vein myocardium undergoes changes in conduction characteristics during postnatal ontogenesis

Cited by 5 publications

References 58 publications

Attenuation of inward rectifier potassium current contributes to the α1‐adrenergic receptor‐induced proarrhythmicity in the caval vein myocardium

Attenuation of inward rectifier potassium current contributes to the α1‐adrenergic receptor‐induced proarrhythmicity in the caval vein myocardium

The susceptibility of the rat pulmonary and caval vein myocardium to the catecholamine‐induced ectopy changes oppositely in postnatal development

α1-adrenergic receptors accompanied by GATA4 expression are related to proarrhythmic conduction and automaticity in rat interatrial septum

Contact Info

Product

Resources

About