A perfused canine right bundle branch-septal model for electrophysiological studies

Arbel, Emanuel R.; Prabhu, Rama; Ramesh, Venkatapura J.; Pick, Ruth; Glick, Gerald

doi:10.1152/ajpheart.1979.236.2.h379

Cited by 4 publications

(4 citation statements)

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“…In our Langendorff-perfused ventricle preparations (without ischemia), it reduced V IS relative to control (Fig. 3), consistent with previous studies (2,31).…”

Section: Perfusate Effects On Myocardiumsupporting

confidence: 92%

“…In all experiments, control Tyrode's solution was perfused for 35 min followed by Tyrode's solution containing either albumin (4 g/l) or mannitol (26.1 g/l/143.2 mOsm), compounds demonstrated to reduce myocardial tissue water content (2,31,35), for 15 min. The osmolarity of the Tyrode's solution with albumin was not significantly different relative to control (290.7 Ϯ 1.8 and 291.0 Ϯ 4.2 mOsm, respectively), whereas the osmolarity of the mannitol solution was significantly higher than both (406.7 Ϯ 1.9 mOsm; P Ͻ 0.05).…”

Section: Guinea Pig Langendorff Preparationsmentioning

confidence: 99%

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Interstitial volume modulates the conduction velocity-gap junction relationship

Veeraraghavan

Salama

Poelzing

2012

American Journal of Physiology-Heart and Circulatory Physiology

126

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Cardiac conduction through gap junctions is an important determinant of arrhythmia susceptibility. Yet, the relationship between degrees of Gj uncoupling and conduction velocity (θ) remains controversial. Conflicting results in similar experiments are normally attributed to experimental differences. We hypothesized that interstitial volume modulates conduction velocity and its dependence on Gj. Interstitial volume (VIS) was quantified histologically from guinea pig right ventricle. Optical mapping was used to quantify conduction velocity and anisotropy (ARθ). Albumin (4 g/l) decreased histologically assessed VIS, increased transverse θ by 71 ± 10%, and lowered ARθ. Furthermore, albumin did not change isolated cell size. Conversely, mannitol increased VIS, decreased transverse θ by 24 ± 4%, and increased ARθ. Mannitol also decreased cell width by 12%. Furthermore, mannitol was associated with spontaneous ventricular tachycardias in three of eight animals relative to zero of 15 during control. The θ-Gj relationship was assessed using the Gj uncoupler carbenoxolone (CBX). Whereas 13 μM CBX did not significantly affect θ during control, it slowed transverse θ by 38 ± 9% during mannitol (edema). These data suggest changes in VIS modulate θ, ARθ, and the θ-Gj relationship and thereby alter arrhythmia susceptibility. Therefore, VIS may underlie arrhythmia susceptibility, particularly in diseases associated with gap junction remodeling.

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“…In our Langendorff-perfused ventricle preparations (without ischemia), it reduced V IS relative to control (Fig. 3), consistent with previous studies (2,31).…”

Section: Perfusate Effects On Myocardiumsupporting

confidence: 92%

Section: Guinea Pig Langendorff Preparationsmentioning

confidence: 99%

Interstitial volume modulates the conduction velocity-gap junction relationship

Veeraraghavan

Salama

Poelzing

2012

American Journal of Physiology-Heart and Circulatory Physiology

126

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“…Myocardial contraction was partially inhibited by an electromechanical uncoupler, 2,3-butanedione monoxime (7.5 mM). Bovine serum albumin (0.4% wt/wt) was added to the perfusate to minimize interstitial edema (28).…”

Section: Isolated Heart Preparationmentioning

confidence: 99%

Orientation dependence of microcirculation‐induced diffusion signal in anisotropic tissues

Abdullah

Gomez

Merchant

et al. 2015

Magnetic Resonance in Med

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Purpose To seek a better understanding of the effect of organized capillary flow on the MR diffusion-weighted signal. Methods A theoretical framework was proposed to describe the diffusion-weighted MR signal, which was then validated both numerically using a realistic model of capillary network and experimentally in an animal model of isolated perfused heart preparation with myocardial blood flow verified by means of direct arterial spin labeling measurements. Results Microcirculation in organized tissues gave rise to an MR signal that could be described as a combination of the bi-exponential behavior of conventional intravoxel incoherent motion (IVIM) theory and diffusion tensor imaging (DTI) -like anisotropy of the vascular signal, with the flow-related pseudo diffusivity represented as the linear algebraic product between the encoding directional unit vector and an appropriate tensor entity. Very good agreement between theoretical predictions and both numerical and experimental observations were found. Conclusion These findings suggest that the DTI formalism of anisotropic spin motion can be incorporated into the classical IVIM theory to describe the MR signal arising from diffusion and microcirculation in organized tissues.

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“…Myocardial edema is common in isolated heart preparations as a consequence of interstitial fluid accumulation and cell swelling 39 . It is known that cell swelling affects several ion channels, including volume-sensitive channels (e.g.…”

Section: Discussionmentioning

confidence: 99%

Effects of gadolinium on cardiac mechanosensitivity in whole isolated swine hearts

Zhang

Walcott

Rogers

2018

Sci Rep

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Mechanical stimulation can elicit electrical activation of the heart. This mechanosensitivity can start life-threatening arrhythmias (commotio cordis) or terminate them (precordial thump). Mechanosensitivity may also be involved in arrhythmogenesis in other settings. Stretch-activated ion channels (SACs) are thought to be important in mechanosensitivity and a number of agents that block them have been identified. Such agents could potentially be used as tools in experimental investigation of mechanosensitivity. However, studies using them in intact-heart preparations have yielded inconsistent results. In the present study, we used isolated, perfused hearts from 25–35 kg pigs and a computer-controlled device that repeatably delivered focal mechanical stimuli. The concentration-dependent ability of the SAC blocker gadolinium to suppress mechanical activation was assessed by the success rate of mechanical stimulation and by the delay between successful mechanical stimulation and electrical activation. In six hearts, perfusate was recirculated. In an additional six hearts, perfusate was not recirculated to prevent gadolinium from forming complexes with metabolic waste and possibly precipitating. Gadolinium did not suppress mechanically-induced activation. Although gadolinium has been shown to be an effective SAC blocker in isolated cells, using it to probe the role of mechanical stimulation in whole heart preparations should be done with great caution.

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A perfused canine right bundle branch-septal model for electrophysiological studies

Abstract: 1) a viable, perfused septal muscle preparation was developed for electrophysiological studies, and 2) colloid oncotic pressure in the perfusion medium is essential to preserve the integrity of the capillary circulation and to eliminate edema formation and tissue death.

Cited by 4 publications

References 0 publications

Interstitial volume modulates the conduction velocity-gap junction relationship

Interstitial volume modulates the conduction velocity-gap junction relationship

Orientation dependence of microcirculation‐induced diffusion signal in anisotropic tissues

Effects of gadolinium on cardiac mechanosensitivity in whole isolated swine hearts

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