Conduction between isolated rabbit Purkinje and  ventricular myocytes coupled by a variable resistance

Huelsing, Delilah J.; Spitzer, Kenneth W.; Cordeiro, Jonathan M.; Pollard, Andrew E.

doi:10.1152/ajpheart.1998.274.4.h1163

Cited by 46 publications

(73 citation statements)

References 29 publications

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“…The single LR model represents in our experiments a T cell, while the strand of LR model cells represents a layer of subendocardial V cells. The present study thus extends the previous studies of Huelsing et al [9,10,11] and Verkerk et al [12] to conditions more closely representing those of the anatomically complex P-V junction. In those previous studies, the "analog coupling clamp" technique was used to study interactions between one real P cell and one real V cell [9,10] or a real P cell, with or without EADs, coupled to a resistance-capacitance circuit, which represented a passive V cell [11,12].…”

Section: Discussionsupporting

confidence: 89%

Action potential transfer at the Purkinje-ventricular junction: role of transitional cells

Verkerk

Veldkamp²,

Ginneken³

et al.

2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society

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-At the Purkinje (P) -ventricular (V) junction a zone of "transitional (T)" cells is found. In the present study we investigated the role of these T cells in P-to-V conduction. Using the "model clamp" technique, an experimentally recorded rabbit P cell was coupled to a phase-2 Luo and Rudy (LR) model cell, which in turn was coupled to a strand of phase-2 LR model cells. In our experiments, the single LR model represents the T cell, while the strand of LR models represents subendocardial V cells. This approach enabled us to change selectively coupling conductance (G c ) between cells, presence of T cell, and relative size of cells. We demonstrated that: 1) a decrease of G c between P-T and T-V increases the delay of V activation, 2) the delay of V activation is importantly due to conduction between T and V cells, 3) there is a critical G c for successful conduction at the P-V junction, 4) the critical value of G c for conduction at the P-V junction is lower in presence (11.0±0.7 nS) than in absence (13.7±0.8 nS) of the T cell, and 5) enlargement of the T zone size hampers successful P-to-V conduction. Keywords -Heart, electrophysiology, gap junction, Purkinjeventricular junction, conduction I. INTRODUCTIONAt the junction between Purkinje (P) fibers and ventricular (V) myocardium a tiny zone is found populated with cells that are called "transitional (T)" [1,2]. The P fibers are connected via short thin branches to sheets of these T cells, which in turn are connected via short thin branches to the V myocardium [3]. This anatomic arrangement is thought to form a high-resistance barrier [3], which may benefit P-to-V conduction by shielding a relatively small P fiber from the electrical load imposed by a relatively large V mass [4]. In addition, it is thought to contribute to the discontinuous conduction at the P-V junction [4,5]. In the present study, we measured the effects of the presence of T cells on action potential transfer at the P-V junction. Using an extended version of the "model clamp" technique [6], we electrically coupled an isolated rabbit cardiac P cell by any desired value of "gap junctional conductance" to a strand of ventricular cells of the phase-2 Luo and Rudy (LR) model [7]. In between, we can add another LR model cell, representing in our experimental set-up the T cell. This approach allowed us to study selectively the importance of T cells in conduction at the P-V junction. II. METHODOLOGYCell preparation. Single P cells were isolated from rabbit hearts by enzymatic dissociation. Hearts were quickly removed from anaesthetized rabbits (1 ml/kg Hypnorm), mounted on a Langendorff perfusion apparatus, and perfused with the following solutions: 1) Tyrode's solution for 10 min; 2) nominally 'Ca 2+ -free' Tyrode's solution for 10 min; and 3) nominally 'Ca 2+ -free' Tyrode's solution with collagenase (59 U/L type B and 150 U/L type P; Boehringer) and 250 mg/L trypsin inhibitor (Boehringer) for 30 min. Subsequently, freerunning P fibers, free from ventricular tissue, were excised from both ven...

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Section: Discussionsupporting

confidence: 89%

Action potential transfer at the Purkinje-ventricular junction: role of transitional cells

Verkerk

Veldkamp²,

Ginneken³

et al.

2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society

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“…By setting R PMJ and K, it is possible to recreate asymmetric propagation across the PMJ with an anterograde transmission delay on the order of 5 ms and retrograde transmission delay on the order of 1 ms as observed experimentally Huelsing et al (1998);Wiedmann et al (1996).…”

Section: Modeling Methodsmentioning

confidence: 99%

The Role of the Purkinje System in Defibrillation

Vigmond¹,

Boyle²,

Deo³

2011

Cardiac Defibrillation - Mechanisms, Challenges and Implications

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“…The coupling clamp has been used to study e.g. electrotonic modulation of the pacemaker activity of the sinoatrial node by the atrial muscle (Watanabe et al 1995), or the interaction between Purkinje cells and ventricular cardiomyocytes (Huelsing et al 1998). In some of these studies (e.g.…”

Section: Ap Clampmentioning

confidence: 99%

Advances in patch clamp technique: towards higher quality and quantity

Bébarová¹

2012

gpb

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Abstract. The patch clamp technique, developed in late 1970s, started a new period of experimental cardiac electrophysiology enabling measurement of ionic currents on isolated cardiomyocytes down to the level of single channels. Since that time, the technique has been substantially improved by development of several upgraded modifications providing so far unavailable data (e.g. action potential clamp, dynamic clamp, high-resolution scanning patch clamp), or facilitating the patch clamp technique by increasing its efficiency (planar patch clamp, automated patch clamp). The current review summarizes the leading new patch clamp based techniques used in cardiac cellular electrophysiology, their principles and prominent related papers.

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Conduction between isolated rabbit Purkinje and ventricular myocytes coupled by a variable resistance

Cited by 46 publications

References 29 publications

Action potential transfer at the Purkinje-ventricular junction: role of transitional cells

Action potential transfer at the Purkinje-ventricular junction: role of transitional cells

The Role of the Purkinje System in Defibrillation

Advances in patch clamp technique: towards higher quality and quantity

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